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| author | richard <richard@57a73879-2fb5-44c3-a270-3262357dd7e2> | |
| Tue, 30 Jul 2002 01:32:35 +0000 (01:32 +0000) | ||
| committer | richard <richard@57a73879-2fb5-44c3-a270-3262357dd7e2> | |
| Tue, 30 Jul 2002 01:32:35 +0000 (01:32 +0000) |
git-svn-id: http://svn.roundup-tracker.org/svnroot/roundup/trunk@927 57a73879-2fb5-44c3-a270-3262357dd7e2
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+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" SYSTEM "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html lang="en">
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+<meta name="generator" content="Docutils: http://docutils.sourceforge.net/">
+<link rel="stylesheet" href="default.css" type="text/css" />
+<title>Roundup - An Issue-Tracking System for Knowledge Workers</title>
+<meta name="author" content="Ka-Ping Yee (original)" />
+<meta name="author" content="Richard Jones (implementation)" />
+</head>
+<body>
+<div class="document" id="roundup-an-issue-tracking-system-for-knowledge-workers" name="roundup-an-issue-tracking-system-for-knowledge-workers">
+<h1 class="title">Roundup - An Issue-Tracking System for Knowledge Workers</h1>
+<table class="docinfo" frame="void" rules="none">
+<col class="docinfo-name" />
+<col class="docinfo-content" />
+<tbody valign="top">
+<tr><td class="docinfo-name">Author: </td><td>
+Ka-Ping Yee (original)</td></tr>
+<tr><td class="docinfo-name">Author: </td><td>
+Richard Jones (implementation)</td></tr>
+</tbody>
+</table>
+<div class="contents topic" id="contents" name="contents">
+<p class="topic-title">Contents</p>
+<ul class="simple">
+<li id="id2" name="id2"><a class="reference" href="#introduction">Introduction</a></li>
+<li id="id3" name="id3"><a class="reference" href="#the-layer-cake">The Layer Cake</a></li>
+<li id="id4" name="id4"><a class="reference" href="#hyperdatabase">Hyperdatabase</a><ul>
+<li id="id5" name="id5"><a class="reference" href="#dates-and-date-arithmetic">Dates and Date Arithmetic</a></li>
+<li id="id6" name="id6"><a class="reference" href="#nodes-and-classes">Nodes and Classes</a></li>
+<li id="id7" name="id7"><a class="reference" href="#identifiers-and-designators">Identifiers and Designators</a></li>
+<li id="id8" name="id8"><a class="reference" href="#property-names-and-types">Property Names and Types</a></li>
+<li id="id9" name="id9"><a class="reference" href="#hyperdb-interface-specification">Hyperdb Interface Specification</a></li>
+<li id="id10" name="id10"><a class="reference" href="#hyperdatabase-implementations">Hyperdatabase Implementations</a></li>
+<li id="id11" name="id11"><a class="reference" href="#application-example">Application Example</a></li>
+</ul>
+</li>
+<li id="id12" name="id12"><a class="reference" href="#roundup-database">Roundup Database</a><ul>
+<li id="id13" name="id13"><a class="reference" href="#reserved-classes">Reserved Classes</a><ul>
+<li id="id14" name="id14"><a class="reference" href="#users">Users</a></li>
+<li id="id15" name="id15"><a class="reference" href="#messages">Messages</a></li>
+<li id="id16" name="id16"><a class="reference" href="#files">Files</a></li>
+</ul>
+</li>
+<li id="id17" name="id17"><a class="reference" href="#issue-classes">Issue Classes</a></li>
+<li id="id18" name="id18"><a class="reference" href="#roundupdb-interface-specification">Roundupdb Interface Specification</a></li>
+<li id="id19" name="id19"><a class="reference" href="#default-schema">Default Schema</a></li>
+</ul>
+</li>
+<li id="id20" name="id20"><a class="reference" href="#detector-interface">Detector Interface</a><ul>
+<li id="id21" name="id21"><a class="reference" href="#detector-interface-specification">Detector Interface Specification</a></li>
+<li id="id22" name="id22"><a class="reference" href="#detector-example">Detector Example</a></li>
+</ul>
+</li>
+<li id="id23" name="id23"><a class="reference" href="#command-interface">Command Interface</a><ul>
+<li id="id24" name="id24"><a class="reference" href="#command-interface-specification">Command Interface Specification</a></li>
+<li id="id25" name="id25"><a class="reference" href="#usage-example">Usage Example</a></li>
+</ul>
+</li>
+<li id="id26" name="id26"><a class="reference" href="#e-mail-user-interface">E-mail User Interface</a><ul>
+<li id="id27" name="id27"><a class="reference" href="#message-processing">Message Processing</a></li>
+<li id="id28" name="id28"><a class="reference" href="#nosy-lists">Nosy Lists</a></li>
+<li id="id29" name="id29"><a class="reference" href="#setting-properties">Setting Properties</a></li>
+</ul>
+</li>
+<li id="id30" name="id30"><a class="reference" href="#web-user-interface">Web User Interface</a><ul>
+<li id="id31" name="id31"><a class="reference" href="#views-and-view-specifiers">Views and View Specifiers</a></li>
+<li id="id32" name="id32"><a class="reference" href="#displaying-properties">Displaying Properties</a></li>
+<li id="id33" name="id33"><a class="reference" href="#index-views">Index Views</a><ul>
+<li id="id34" name="id34"><a class="reference" href="#index-view-specifiers">Index View Specifiers</a></li>
+<li id="id35" name="id35"><a class="reference" href="#filter-section">Filter Section</a></li>
+<li id="id36" name="id36"><a class="reference" href="#index-section">Index Section</a></li>
+<li id="id37" name="id37"><a class="reference" href="#sorting">Sorting</a></li>
+</ul>
+</li>
+<li id="id38" name="id38"><a class="reference" href="#issue-views">Issue Views</a><ul>
+<li id="id39" name="id39"><a class="reference" href="#issue-view-specifiers">Issue View Specifiers</a></li>
+<li id="id40" name="id40"><a class="reference" href="#editor-section">Editor Section</a></li>
+<li id="id41" name="id41"><a class="reference" href="#spool-section">Spool Section</a></li>
+</ul>
+</li>
+</ul>
+</li>
+<li id="id42" name="id42"><a class="reference" href="#deployment-scenarios">Deployment Scenarios</a></li>
+<li id="id43" name="id43"><a class="reference" href="#acknowledgements">Acknowledgements</a></li>
+<li id="id44" name="id44"><a class="reference" href="#changes-to-this-document">Changes to this document</a></li>
+</ul>
+</div>
+<div class="section" id="introduction" name="introduction">
+<h1><a class="toc-backref" href="#id2">Introduction</a></h1>
+<p>This document presents a description of the components
+of the Roundup system and specifies their interfaces and
+behaviour in sufficient detail to guide an implementation.
+For the philosophy and rationale behind the Roundup design,
+see the first-round Software Carpentry submission for Roundup.
+This document fleshes out that design as well as specifying
+interfaces so that the components can be developed separately.</p>
+</div>
+<div class="section" id="the-layer-cake" name="the-layer-cake">
+<h1><a class="toc-backref" href="#id3">The Layer Cake</a></h1>
+<p>Lots of software design documents come with a picture of
+a cake. Everybody seems to like them. I also like cakes
+(i think they are tasty). So i, too, shall include
+a picture of a cake here:</p>
+<pre class="literal-block"> _________________________________________________________________________
+| E-mail Client | Web Browser | Detector Scripts | Shell |
+|------------------+-----------------+----------------------+-------------|
+| E-mail User | Web User | Detector | Command |
+|-------------------------------------------------------------------------|
+| Roundup Database Layer |
+|-------------------------------------------------------------------------|
+| Hyperdatabase Layer |
+|-------------------------------------------------------------------------|
+| Storage Layer |
+ -------------------------------------------------------------------------</pre>
+<p>The colourful parts of the cake are part of our system;
+the faint grey parts of the cake are external components.</p>
+<p>I will now proceed to forgo all table manners and
+eat from the bottom of the cake to the top. You may want
+to stand back a bit so you don't get covered in crumbs.</p>
+</div>
+<div class="section" id="hyperdatabase" name="hyperdatabase">
+<h1><a class="toc-backref" href="#id4">Hyperdatabase</a></h1>
+<p>The lowest-level component to be implemented is the hyperdatabase.
+The hyperdatabase is intended to be
+a flexible data store that can hold configurable data in
+records which we call nodes.</p>
+<p>The hyperdatabase is implemented on top of the storage layer,
+an external module for storing its data. The storage layer could
+be a third-party RDBMS; for a "batteries-included" distribution,
+implementing the hyperdatabase on the standard bsddb
+module is suggested.</p>
+<div class="section" id="dates-and-date-arithmetic" name="dates-and-date-arithmetic">
+<h2><a class="toc-backref" href="#id5">Dates and Date Arithmetic</a></h2>
+<p>Before we get into the hyperdatabase itself, we need a
+way of handling dates. The hyperdatabase module provides
+Timestamp objects for
+representing date-and-time stamps and Interval objects for
+representing date-and-time intervals.</p>
+<p>As strings, date-and-time stamps are specified with
+the date in international standard format
+(<tt class="literal">yyyy-mm-dd</tt>)
+joined to the time (<tt class="literal">hh:mm:ss</tt>)
+by a period "<tt class="literal">.</tt>". Dates in
+this form can be easily compared and are fairly readable
+when printed. An example of a valid stamp is
+"<tt class="literal">2000-06-24.13:03:59</tt>".
+We'll call this the "full date format". When Timestamp objects are
+printed as strings, they appear in the full date format with
+the time always given in GMT. The full date format is always
+exactly 19 characters long.</p>
+<p>For user input, some partial forms are also permitted:
+the whole time or just the seconds may be omitted; and the whole date
+may be omitted or just the year may be omitted. If the time is given,
+the time is interpreted in the user's local time zone.
+The Date constructor takes care of these conversions.
+In the following examples, suppose that <tt class="literal">yyyy</tt> is the current year,
+<tt class="literal">mm</tt> is the current month, and <tt class="literal">dd</tt> is the current
+day of the month; and suppose that the user is on Eastern Standard Time.</p>
+<ul class="simple">
+<li>"2000-04-17" means <Date 2000-04-17.00:00:00></li>
+<li>"01-25" means <Date yyyy-01-25.00:00:00></li>
+<li>"2000-04-17.03:45" means <Date 2000-04-17.08:45:00></li>
+<li>"08-13.22:13" means <Date yyyy-08-14.03:13:00></li>
+<li>"11-07.09:32:43" means <Date yyyy-11-07.14:32:43></li>
+<li>"14:25" means</li>
+<li><Date yyyy-mm-dd.19:25:00></li>
+<li>"8:47:11" means</li>
+<li><Date yyyy-mm-dd.13:47:11></li>
+<li>the special date "." means "right now"</li>
+</ul>
+<p>Date intervals are specified using the suffixes
+"y", "m", and "d". The suffix "w" (for "week") means 7 days.
+Time intervals are specified in hh:mm:ss format (the seconds
+may be omitted, but the hours and minutes may not).</p>
+<ul class="simple">
+<li>"3y" means three years</li>
+<li>"2y 1m" means two years and one month</li>
+<li>"1m 25d" means one month and 25 days</li>
+<li>"2w 3d" means two weeks and three days</li>
+<li>"1d 2:50" means one day, two hours, and 50 minutes</li>
+<li>"14:00" means 14 hours</li>
+<li>"0:04:33" means four minutes and 33 seconds</li>
+</ul>
+<p>The Date class should understand simple date expressions of the form
+<em>stamp</em> <tt class="literal">+</tt> <em>interval</em> and <em>stamp</em> <tt class="literal">-</tt> <em>interval</em>.
+When adding or subtracting intervals involving months or years, the
+components are handled separately. For example, when evaluating
+"<tt class="literal">2000-06-25 + 1m 10d</tt>", we first add one month to
+get 2000-07-25, then add 10 days to get
+2000-08-04 (rather than trying to decide whether
+1m 10d means 38 or 40 or 41 days).</p>
+<p>Here is an outline of the Date and Interval classes:</p>
+<pre class="literal-block">class Date:
+ def __init__(self, spec, offset):
+ """Construct a date given a specification and a time zone offset.
+
+ 'spec' is a full date or a partial form, with an optional
+ added or subtracted interval. 'offset' is the local time
+ zone offset from GMT in hours.
+ """
+
+ def __add__(self, interval):
+ """Add an interval to this date to produce another date."""
+
+ def __sub__(self, interval):
+ """Subtract an interval from this date to produce another date."""
+
+ def __cmp__(self, other):
+ """Compare this date to another date."""
+
+ def __str__(self):
+ """Return this date as a string in the yyyy-mm-dd.hh:mm:ss format."""
+
+ def local(self, offset):
+ """Return this date as yyyy-mm-dd.hh:mm:ss in a local time zone."""
+
+class Interval:
+ def __init__(self, spec):
+ """Construct an interval given a specification."""
+
+ def __cmp__(self, other):
+ """Compare this interval to another interval."""
+
+ def __str__(self):
+ """Return this interval as a string."""</pre>
+<p>Here are some examples of how these classes would behave in practice.
+For the following examples, assume that we are on Eastern Standard
+Time and the current local time is 19:34:02 on 25 June 2000:</p>
+<pre class="literal-block">>>> Date(".")
+<Date 2000-06-26.00:34:02>
+>>> _.local(-5)
+"2000-06-25.19:34:02"
+>>> Date(". + 2d")
+<Date 2000-06-28.00:34:02>
+>>> Date("1997-04-17", -5)
+<Date 1997-04-17.00:00:00>
+>>> Date("01-25", -5)
+<Date 2000-01-25.00:00:00>
+>>> Date("08-13.22:13", -5)
+<Date 2000-08-14.03:13:00>
+>>> Date("14:25", -5)
+<Date 2000-06-25.19:25:00>
+>>> Interval(" 3w 1 d 2:00")
+<Interval 22d 2:00>
+>>> Date(". + 2d") - Interval("3w")
+<Date 2000-06-07.00:34:02></pre>
+</div>
+<div class="section" id="nodes-and-classes" name="nodes-and-classes">
+<h2><a class="toc-backref" href="#id6">Nodes and Classes</a></h2>
+<p>Nodes contain data in properties. To Python, these
+properties are presented as the key-value pairs of a dictionary.
+Each node belongs to a class which defines the names
+and types of its properties. The database permits the creation
+and modification of classes as well as nodes.</p>
+</div>
+<div class="section" id="identifiers-and-designators" name="identifiers-and-designators">
+<h2><a class="toc-backref" href="#id7">Identifiers and Designators</a></h2>
+<p>Each node has a numeric identifier which is unique among
+nodes in its class. The nodes are numbered sequentially
+within each class in order of creation, starting from 1.
+The designator
+for a node is a way to identify a node in the database, and
+consists of the name of the node's class concatenated with
+the node's numeric identifier.</p>
+<p>For example, if "spam" and "eggs" are classes, the first
+node created in class "spam" has id 1 and designator "spam1".
+The first node created in class "eggs" also has id 1 but has
+the distinct designator "eggs1". Node designators are
+conventionally enclosed in square brackets when mentioned
+in plain text. This permits a casual mention of, say,
+"[patch37]" in an e-mail message to be turned into an active
+hyperlink.</p>
+</div>
+<div class="section" id="property-names-and-types" name="property-names-and-types">
+<h2><a class="toc-backref" href="#id8">Property Names and Types</a></h2>
+<p>Property names must begin with a letter.</p>
+<p>A property may be one of five basic types:</p>
+<ul class="simple">
+<li>String properties are for storing arbitrary-length strings.</li>
+<li>Boolean properties are for storing true/false, or yes/no values.</li>
+<li>Number properties are for storing numeric values.</li>
+<li>Date properties store date-and-time stamps.
+Their values are Timestamp objects.</li>
+<li>A Link property refers to a single other node
+selected from a specified class. The class is part of the property;
+the value is an integer, the id of the chosen node.</li>
+<li>A Multilink property refers to possibly many nodes
+in a specified class. The value is a list of integers.</li>
+</ul>
+<p><em>None</em> is also a permitted value for any of these property
+types. An attempt to store None into a Multilink property stores an empty list.</p>
+<p>A property that is not specified will return as None from a <em>get</em>
+operation.</p>
+</div>
+<div class="section" id="hyperdb-interface-specification" name="hyperdb-interface-specification">
+<h2><a class="toc-backref" href="#id9">Hyperdb Interface Specification</a></h2>
+<p>The hyperdb module provides property objects to designate
+the different kinds of properties. These objects are used when
+specifying what properties belong in classes:</p>
+<pre class="literal-block">class String:
+ def __init__(self, indexme='no'):
+ """An object designating a String property."""
+
+class Boolean:
+ def __init__(self):
+ """An object designating a Boolean property."""
+
+class Number:
+ def __init__(self):
+ """An object designating a Number property."""
+
+class Date:
+ def __init__(self):
+ """An object designating a Date property."""
+
+class Link:
+ def __init__(self, classname, do_journal='yes'):
+ """An object designating a Link property that links to
+ nodes in a specified class.
+
+ If the do_journal argument is not 'yes' then changes to
+ the property are not journalled in the linked node.
+ """
+
+class Multilink:
+ def __init__(self, classname, do_journal='yes'):
+ """An object designating a Multilink property that links
+ to nodes in a specified class.
+
+ If the do_journal argument is not 'yes' then changes to
+ the property are not journalled in the linked node(s).
+ """</pre>
+<p>Here is the interface provided by the hyperdatabase:</p>
+<pre class="literal-block">class Database:
+ """A database for storing records containing flexible data types."""
+
+ def __init__(self, storagelocator, journaltag):
+ """Open a hyperdatabase given a specifier to some storage.
+
+ The meaning of 'storagelocator' depends on the particular
+ implementation of the hyperdatabase. It could be a file name,
+ a directory path, a socket descriptor for a connection to a
+ database over the network, etc.
+
+ The 'journaltag' is a token that will be attached to the journal
+ entries for any edits done on the database. If 'journaltag' is
+ None, the database is opened in read-only mode: the Class.create(),
+ Class.set(), and Class.retire() methods are disabled.
+ """
+
+ def __getattr__(self, classname):
+ """A convenient way of calling self.getclass(classname)."""
+
+ def getclasses(self):
+ """Return a list of the names of all existing classes."""
+
+ def getclass(self, classname):
+ """Get the Class object representing a particular class.
+
+ If 'classname' is not a valid class name, a KeyError is raised.
+ """
+
+class Class:
+ """The handle to a particular class of nodes in a hyperdatabase."""
+
+ def __init__(self, db, classname, **properties):
+ """Create a new class with a given name and property specification.
+
+ 'classname' must not collide with the name of an existing class,
+ or a ValueError is raised. The keyword arguments in 'properties'
+ must map names to property objects, or a TypeError is raised.
+ """
+
+ # Editing nodes:
+
+ def create(self, **propvalues):
+ """Create a new node of this class and return its id.
+
+ The keyword arguments in 'propvalues' map property names to values.
+ The values of arguments must be acceptable for the types of their
+ corresponding properties or a TypeError is raised. If this class
+ has a key property, it must be present and its value must not
+ collide with other key strings or a ValueError is raised. Any other
+ properties on this class that are missing from the 'propvalues'
+ dictionary are set to None. If an id in a link or multilink
+ property does not refer to a valid node, an IndexError is raised.
+ """
+
+ def get(self, nodeid, propname):
+ """Get the value of a property on an existing node of this class.
+
+ 'nodeid' must be the id of an existing node of this class or an
+ IndexError is raised. 'propname' must be the name of a property
+ of this class or a KeyError is raised.
+ """
+
+ def set(self, nodeid, **propvalues):
+ """Modify a property on an existing node of this class.
+
+ 'nodeid' must be the id of an existing node of this class or an
+ IndexError is raised. Each key in 'propvalues' must be the name
+ of a property of this class or a KeyError is raised. All values
+ in 'propvalues' must be acceptable types for their corresponding
+ properties or a TypeError is raised. If the value of the key
+ property is set, it must not collide with other key strings or a
+ ValueError is raised. If the value of a Link or Multilink
+ property contains an invalid node id, a ValueError is raised.
+ """
+
+ def retire(self, nodeid):
+ """Retire a node.
+
+ The properties on the node remain available from the get() method,
+ and the node's id is never reused. Retired nodes are not returned
+ by the find(), list(), or lookup() methods, and other nodes may
+ reuse the values of their key properties.
+ """
+
+ def history(self, nodeid):
+ """Retrieve the journal of edits on a particular node.
+
+ 'nodeid' must be the id of an existing node of this class or an
+ IndexError is raised.
+
+ The returned list contains tuples of the form
+
+ (date, tag, action, params)
+
+ 'date' is a Timestamp object specifying the time of the change and
+ 'tag' is the journaltag specified when the database was opened.
+ 'action' may be:
+
+ 'create' or 'set' -- 'params' is a dictionary of property values
+ 'link' or 'unlink' -- 'params' is (classname, nodeid, propname)
+ 'retire' -- 'params' is None
+ """
+
+ # Locating nodes:
+
+ def setkey(self, propname):
+ """Select a String property of this class to be the key property.
+
+ 'propname' must be the name of a String property of this class or
+ None, or a TypeError is raised. The values of the key property on
+ all existing nodes must be unique or a ValueError is raised.
+ """
+
+ def getkey(self):
+ """Return the name of the key property for this class or None."""
+
+ def lookup(self, keyvalue):
+ """Locate a particular node by its key property and return its id.
+
+ If this class has no key property, a TypeError is raised. If the
+ 'keyvalue' matches one of the values for the key property among
+ the nodes in this class, the matching node's id is returned;
+ otherwise a KeyError is raised.
+ """
+
+ def find(self, propname, nodeid):
+ """Get the ids of nodes in this class which link to a given node.
+
+ 'propname' must be the name of a property in this class, or a
+ KeyError is raised. That property must be a Link or Multilink
+ property, or a TypeError is raised. 'nodeid' must be the id of
+ an existing node in the class linked to by the given property,
+ or an IndexError is raised.
+ """
+
+ def list(self):
+ """Return a list of the ids of the active nodes in this class."""
+
+ def count(self):
+ """Get the number of nodes in this class.
+
+ If the returned integer is 'numnodes', the ids of all the nodes
+ in this class run from 1 to numnodes, and numnodes+1 will be the
+ id of the next node to be created in this class.
+ """
+
+ # Manipulating properties:
+
+ def getprops(self):
+ """Return a dictionary mapping property names to property objects."""
+
+ def addprop(self, **properties):
+ """Add properties to this class.
+
+ The keyword arguments in 'properties' must map names to property
+ objects, or a TypeError is raised. None of the keys in 'properties'
+ may collide with the names of existing properties, or a ValueError
+ is raised before any properties have been added.
+ """</pre>
+<p>TODO: additional methods</p>
+</div>
+<div class="section" id="hyperdatabase-implementations" name="hyperdatabase-implementations">
+<h2><a class="toc-backref" href="#id10">Hyperdatabase Implementations</a></h2>
+<p>Hyperdatabase implementations exist to create the interface described in the
+<a class="reference" href="#hyperdb-interface-specification">hyperdb interface specification</a>
+over an existing storage mechanism. Examples are relational databases,
+*dbm key-value databases, and so on.</p>
+<p>TODO: finish</p>
+</div>
+<div class="section" id="application-example" name="application-example">
+<h2><a class="toc-backref" href="#id11">Application Example</a></h2>
+<p>Here is an example of how the hyperdatabase module would work in practice:</p>
+<pre class="literal-block">>>> import hyperdb
+>>> db = hyperdb.Database("foo.db", "ping")
+>>> db
+<hyperdb.Database "foo.db" opened by "ping">
+>>> hyperdb.Class(db, "status", name=hyperdb.String())
+<hyperdb.Class "status">
+>>> _.setkey("name")
+>>> db.status.create(name="unread")
+1
+>>> db.status.create(name="in-progress")
+2
+>>> db.status.create(name="testing")
+3
+>>> db.status.create(name="resolved")
+4
+>>> db.status.count()
+4
+>>> db.status.list()
+[1, 2, 3, 4]
+>>> db.status.lookup("in-progress")
+2
+>>> db.status.retire(3)
+>>> db.status.list()
+[1, 2, 4]
+>>> hyperdb.Class(db, "issue", title=hyperdb.String(), status=hyperdb.Link("status"))
+<hyperdb.Class "issue">
+>>> db.issue.create(title="spam", status=1)
+1
+>>> db.issue.create(title="eggs", status=2)
+2
+>>> db.issue.create(title="ham", status=4)
+3
+>>> db.issue.create(title="arguments", status=2)
+4
+>>> db.issue.create(title="abuse", status=1)
+5
+>>> hyperdb.Class(db, "user", username=hyperdb.Key(), password=hyperdb.String())
+<hyperdb.Class "user">
+>>> db.issue.addprop(fixer=hyperdb.Link("user"))
+>>> db.issue.getprops()
+{"title": <hyperdb.String>, "status": <hyperdb.Link to "status">,
+ "user": <hyperdb.Link to "user">}
+>>> db.issue.set(5, status=2)
+>>> db.issue.get(5, "status")
+2
+>>> db.status.get(2, "name")
+"in-progress"
+>>> db.issue.get(5, "title")
+"abuse"
+>>> db.issue.find("status", db.status.lookup("in-progress"))
+[2, 4, 5]
+>>> db.issue.history(5)
+[(<Date 2000-06-28.19:09:43>, "ping", "create", {"title": "abuse", "status": 1}),
+ (<Date 2000-06-28.19:11:04>, "ping", "set", {"status": 2})]
+>>> db.status.history(1)
+[(<Date 2000-06-28.19:09:43>, "ping", "link", ("issue", 5, "status")),
+ (<Date 2000-06-28.19:11:04>, "ping", "unlink", ("issue", 5, "status"))]
+>>> db.status.history(2)
+[(<Date 2000-06-28.19:11:04>, "ping", "link", ("issue", 5, "status"))]</pre>
+<p>For the purposes of journalling, when a Multilink property is
+set to a new list of nodes, the hyperdatabase compares the old
+list to the new list.
+The journal records "unlink" events for all the nodes that appear
+in the old list but not the new list,
+and "link" events for
+all the nodes that appear in the new list but not in the old list.</p>
+</div>
+</div>
+<div class="section" id="roundup-database" name="roundup-database">
+<h1><a class="toc-backref" href="#id12">Roundup Database</a></h1>
+<p>The Roundup database layer is implemented on top of the
+hyperdatabase and mediates calls to the database.
+Some of the classes in the Roundup database are considered
+issue classes.
+The Roundup database layer adds detectors and user nodes,
+and on issues it provides mail spools, nosy lists, and superseders.</p>
+<p>TODO: where functionality is implemented.</p>
+<div class="section" id="reserved-classes" name="reserved-classes">
+<h2><a class="toc-backref" href="#id13">Reserved Classes</a></h2>
+<p>Internal to this layer we reserve three special classes
+of nodes that are not issues.</p>
+<div class="section" id="users" name="users">
+<h3><a class="toc-backref" href="#id14">Users</a></h3>
+<p>Users are stored in the hyperdatabase as nodes of
+class "user". The "user" class has the definition:</p>
+<pre class="literal-block">hyperdb.Class(db, "user", username=hyperdb.String(),
+ password=hyperdb.String(),
+ address=hyperdb.String())
+db.user.setkey("username")</pre>
+</div>
+<div class="section" id="messages" name="messages">
+<h3><a class="toc-backref" href="#id15">Messages</a></h3>
+<p>E-mail messages are represented by hyperdatabase nodes of class "msg".
+The actual text content of the messages is stored in separate files.
+(There's no advantage to be gained by stuffing them into the
+hyperdatabase, and if messages are stored in ordinary text files,
+they can be grepped from the command line.) The text of a message is
+saved in a file named after the message node designator (e.g. "msg23")
+for the sake of the command interface (see below). Attachments are
+stored separately and associated with "file" nodes.
+The "msg" class has the definition:</p>
+<pre class="literal-block">hyperdb.Class(db, "msg", author=hyperdb.Link("user"),
+ recipients=hyperdb.Multilink("user"),
+ date=hyperdb.Date(),
+ summary=hyperdb.String(),
+ files=hyperdb.Multilink("file"))</pre>
+<p>The "author" property indicates the author of the message
+(a "user" node must exist in the hyperdatabase for any messages
+that are stored in the system).
+The "summary" property contains a summary of the message for display
+in a message index.</p>
+</div>
+<div class="section" id="files" name="files">
+<h3><a class="toc-backref" href="#id16">Files</a></h3>
+<p>Submitted files are represented by hyperdatabase
+nodes of class "file". Like e-mail messages, the file content
+is stored in files outside the database,
+named after the file node designator (e.g. "file17").
+The "file" class has the definition:</p>
+<pre class="literal-block">hyperdb.Class(db, "file", user=hyperdb.Link("user"),
+ name=hyperdb.String(),
+ type=hyperdb.String())</pre>
+<p>The "user" property indicates the user who submitted the
+file, the "name" property holds the original name of the file,
+and the "type" property holds the MIME type of the file as received.</p>
+</div>
+</div>
+<div class="section" id="issue-classes" name="issue-classes">
+<h2><a class="toc-backref" href="#id17">Issue Classes</a></h2>
+<p>All issues have the following standard properties:</p>
+<table frame="border" rules="all">
+<colgroup>
+<col colwidth="30%" />
+<col colwidth="70%" />
+</colgroup>
+<thead valign="bottom">
+<tr><th>Property</th>
+<th>Definition</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr><td>title</td>
+<td>hyperdb.String()</td>
+</tr>
+<tr><td>messages</td>
+<td>hyperdb.Multilink("msg")</td>
+</tr>
+<tr><td>files</td>
+<td>hyperdb.Multilink("file")</td>
+</tr>
+<tr><td>nosy</td>
+<td>hyperdb.Multilink("user")</td>
+</tr>
+<tr><td>superseder</td>
+<td>hyperdb.Multilink("issue")</td>
+</tr>
+</tbody>
+</table>
+<p>Also, two Date properties named "creation" and "activity" are
+fabricated by the Roundup database layer. By "fabricated" we
+mean that no such properties are actually stored in the
+hyperdatabase, but when properties on issues are requested, the
+"creation" and "activity" properties are made available.
+The value of the "creation" property is the date when an issue was
+created, and the value of the "activity" property is the
+date when any property on the issue was last edited (equivalently,
+these are the dates on the first and last records in the issue's journal).</p>
+</div>
+<div class="section" id="roundupdb-interface-specification" name="roundupdb-interface-specification">
+<h2><a class="toc-backref" href="#id18">Roundupdb Interface Specification</a></h2>
+<p>The interface to a Roundup database delegates most method
+calls to the hyperdatabase, except for the following
+changes and additional methods:</p>
+<pre class="literal-block">class Database:
+ def getuid(self):
+ """Return the id of the "user" node associated with the user
+ that owns this connection to the hyperdatabase."""
+
+class Class:
+ # Overridden methods:
+
+ def create(self, **propvalues):
+ def set(self, **propvalues):
+ def retire(self, nodeid):
+ """These operations trigger detectors and can be vetoed. Attempts
+ to modify the "creation" or "activity" properties cause a KeyError.
+ """
+
+ # New methods:
+
+ def audit(self, event, detector):
+ def react(self, event, detector):
+ """Register a detector (see below for more details)."""
+
+class IssueClass(Class):
+ # Overridden methods:
+
+ def __init__(self, db, classname, **properties):
+ """The newly-created class automatically includes the "messages",
+ "files", "nosy", and "superseder" properties. If the 'properties'
+ dictionary attempts to specify any of these properties or a
+ "creation" or "activity" property, a ValueError is raised."""
+
+ def get(self, nodeid, propname):
+ def getprops(self):
+ """In addition to the actual properties on the node, these
+ methods provide the "creation" and "activity" properties."""
+
+ # New methods:
+
+ def addmessage(self, nodeid, summary, text):
+ """Add a message to an issue's mail spool.
+
+ A new "msg" node is constructed using the current date, the
+ user that owns the database connection as the author, and
+ the specified summary text. The "files" and "recipients"
+ fields are left empty. The given text is saved as the body
+ of the message and the node is appended to the "messages"
+ field of the specified issue.
+ """
+
+ def sendmessage(self, nodeid, msgid):
+ """Send a message to the members of an issue's nosy list.
+
+ The message is sent only to users on the nosy list who are not
+ already on the "recipients" list for the message. These users
+ are then added to the message's "recipients" list.
+ """</pre>
+</div>
+<div class="section" id="default-schema" name="default-schema">
+<h2><a class="toc-backref" href="#id19">Default Schema</a></h2>
+<p>The default schema included with Roundup turns it into a
+typical software bug tracker. The database is set up like this:</p>
+<pre class="literal-block">pri = Class(db, "priority", name=hyperdb.String(), order=hyperdb.String())
+pri.setkey("name")
+pri.create(name="critical", order="1")
+pri.create(name="urgent", order="2")
+pri.create(name="bug", order="3")
+pri.create(name="feature", order="4")
+pri.create(name="wish", order="5")
+
+stat = Class(db, "status", name=hyperdb.String(), order=hyperdb.String())
+stat.setkey("name")
+stat.create(name="unread", order="1")
+stat.create(name="deferred", order="2")
+stat.create(name="chatting", order="3")
+stat.create(name="need-eg", order="4")
+stat.create(name="in-progress", order="5")
+stat.create(name="testing", order="6")
+stat.create(name="done-cbb", order="7")
+stat.create(name="resolved", order="8")
+
+Class(db, "keyword", name=hyperdb.String())
+
+Class(db, "issue", fixer=hyperdb.Multilink("user"),
+ topic=hyperdb.Multilink("keyword"),
+ priority=hyperdb.Link("priority"),
+ status=hyperdb.Link("status"))</pre>
+<p>(The "order" property hasn't been explained yet. It
+gets used by the Web user interface for sorting.)</p>
+<p>The above isn't as pretty-looking as the schema specification
+in the first-stage submission, but it could be made just as easy
+with the addition of a convenience function like Choice
+for setting up the "priority" and "status" classes:</p>
+<pre class="literal-block">def Choice(name, *options):
+ cl = Class(db, name, name=hyperdb.String(), order=hyperdb.String())
+ for i in range(len(options)):
+ cl.create(name=option[i], order=i)
+ return hyperdb.Link(name)</pre>
+</div>
+</div>
+<div class="section" id="detector-interface" name="detector-interface">
+<h1><a class="toc-backref" href="#id20">Detector Interface</a></h1>
+<p>Detectors are Python functions that are triggered on certain
+kinds of events. The definitions of the
+functions live in Python modules placed in a directory set aside
+for this purpose. Importing the Roundup database module also
+imports all the modules in this directory, and the <tt class="literal">init()</tt>
+function of each module is called when a database is opened to
+provide it a chance to register its detectors.</p>
+<p>There are two kinds of detectors:</p>
+<ol class="arabic simple">
+<li>an auditor is triggered just before modifying an node</li>
+<li>a reactor is triggered just after an node has been modified</li>
+</ol>
+<p>When the Roundup database is about to perform a
+<tt class="literal">create()</tt>, <tt class="literal">set()</tt>, or <tt class="literal">retire()</tt>
+operation, it first calls any <em>auditors</em> that
+have been registered for that operation on that class.
+Any auditor may raise a <em>Reject</em> exception
+to abort the operation.</p>
+<p>If none of the auditors raises an exception, the database
+proceeds to carry out the operation. After it's done, it
+then calls all of the <em>reactors</em> that have been registered
+for the operation.</p>
+<div class="section" id="detector-interface-specification" name="detector-interface-specification">
+<h2><a class="toc-backref" href="#id21">Detector Interface Specification</a></h2>
+<p>The <tt class="literal">audit()</tt> and <tt class="literal">react()</tt> methods
+register detectors on a given class of nodes:</p>
+<pre class="literal-block">class Class:
+ def audit(self, event, detector):
+ """Register an auditor on this class.
+
+ 'event' should be one of "create", "set", or "retire".
+ 'detector' should be a function accepting four arguments.
+ """
+
+ def react(self, event, detector):
+ """Register a reactor on this class.
+
+ 'event' should be one of "create", "set", or "retire".
+ 'detector' should be a function accepting four arguments.
+ """</pre>
+<p>Auditors are called with the arguments:</p>
+<pre class="literal-block">audit(db, cl, nodeid, newdata)</pre>
+<p>where <tt class="literal">db</tt> is the database, <tt class="literal">cl</tt> is an
+instance of Class or IssueClass within the database, and <tt class="literal">newdata</tt>
+is a dictionary mapping property names to values.</p>
+<p>For a <tt class="literal">create()</tt>
+operation, the <tt class="literal">nodeid</tt> argument is None and newdata
+contains all of the initial property values with which the node
+is about to be created.</p>
+<p>For a <tt class="literal">set()</tt> operation, newdata
+contains only the names and values of properties that are about
+to be changed.</p>
+<p>For a <tt class="literal">retire()</tt> operation, newdata is None.</p>
+<p>Reactors are called with the arguments:</p>
+<pre class="literal-block">react(db, cl, nodeid, olddata)</pre>
+<p>where <tt class="literal">db</tt> is the database, <tt class="literal">cl</tt> is an
+instance of Class or IssueClass within the database, and <tt class="literal">olddata</tt>
+is a dictionary mapping property names to values.</p>
+<p>For a <tt class="literal">create()</tt>
+operation, the <tt class="literal">nodeid</tt> argument is the id of the
+newly-created node and <tt class="literal">olddata</tt> is None.</p>
+<p>For a <tt class="literal">set()</tt> operation, <tt class="literal">olddata</tt>
+contains the names and previous values of properties that were changed.</p>
+<p>For a <tt class="literal">retire()</tt> operation, <tt class="literal">nodeid</tt> is the
+id of the retired node and <tt class="literal">olddata</tt> is None.</p>
+</div>
+<div class="section" id="detector-example" name="detector-example">
+<h2><a class="toc-backref" href="#id22">Detector Example</a></h2>
+<p>Here is an example of detectors written for a hypothetical
+project-management application, where users can signal approval
+of a project by adding themselves to an "approvals" list, and
+a project proceeds when it has three approvals:</p>
+<pre class="literal-block"># Permit users only to add themselves to the "approvals" list.
+
+def check_approvals(db, cl, id, newdata):
+ if newdata.has_key("approvals"):
+ if cl.get(id, "status") == db.status.lookup("approved"):
+ raise Reject, "You can't modify the approvals list " \
+ "for a project that has already been approved."
+ old = cl.get(id, "approvals")
+ new = newdata["approvals"]
+ for uid in old:
+ if uid not in new and uid != db.getuid():
+ raise Reject, "You can't remove other users from the "
+ "approvals list; you can only remove yourself."
+ for uid in new:
+ if uid not in old and uid != db.getuid():
+ raise Reject, "You can't add other users to the approvals "
+ "list; you can only add yourself."
+
+# When three people have approved a project, change its
+# status from "pending" to "approved".
+
+def approve_project(db, cl, id, olddata):
+ if olddata.has_key("approvals") and len(cl.get(id, "approvals")) == 3:
+ if cl.get(id, "status") == db.status.lookup("pending"):
+ cl.set(id, status=db.status.lookup("approved"))
+
+def init(db):
+ db.project.audit("set", check_approval)
+ db.project.react("set", approve_project)</pre>
+<p>Here is another example of a detector that can allow or prevent
+the creation of new nodes. In this scenario, patches for a software
+project are submitted by sending in e-mail with an attached file,
+and we want to ensure that there are text/plain attachments on
+the message. The maintainer of the package can then apply the
+patch by setting its status to "applied":</p>
+<pre class="literal-block"># Only accept attempts to create new patches that come with patch files.
+
+def check_new_patch(db, cl, id, newdata):
+ if not newdata["files"]:
+ raise Reject, "You can't submit a new patch without " \
+ "attaching a patch file."
+ for fileid in newdata["files"]:
+ if db.file.get(fileid, "type") != "text/plain":
+ raise Reject, "Submitted patch files must be text/plain."
+
+# When the status is changed from "approved" to "applied", apply the patch.
+
+def apply_patch(db, cl, id, olddata):
+ if cl.get(id, "status") == db.status.lookup("applied") and \
+ olddata["status"] == db.status.lookup("approved"):
+ # ...apply the patch...
+
+def init(db):
+ db.patch.audit("create", check_new_patch)
+ db.patch.react("set", apply_patch)</pre>
+</div>
+</div>
+<div class="section" id="command-interface" name="command-interface">
+<h1><a class="toc-backref" href="#id23">Command Interface</a></h1>
+<p>The command interface is a very simple and minimal interface,
+intended only for quick searches and checks from the shell prompt.
+(Anything more interesting can simply be written in Python using
+the Roundup database module.)</p>
+<div class="section" id="command-interface-specification" name="command-interface-specification">
+<h2><a class="toc-backref" href="#id24">Command Interface Specification</a></h2>
+<p>A single command, roundup, provides basic access to
+the hyperdatabase from the command line:</p>
+<pre class="literal-block">roundup get [-list] designator[, designator,...] propname
+roundup set designator[, designator,...] propname=value ...
+roundup find [-list] classname propname=value ...</pre>
+<p>TODO: more stuff here</p>
+<p>Property values are represented as strings in command arguments
+and in the printed results:</p>
+<ul class="simple">
+<li>Strings are, well, strings.</li>
+<li>Numbers are displayed the same as strings.</li>
+<li>Booleans are displayed as 'Yes' or 'No'.</li>
+<li>Date values are printed in the full date format in the local
+time zone, and accepted in the full format or any of the partial
+formats explained above.</li>
+<li>Link values are printed as node designators. When given as
+an argument, node designators and key strings are both accepted.</li>
+<li>Multilink values are printed as lists of node designators
+joined by commas. When given as an argument, node designators
+and key strings are both accepted; an empty string, a single node,
+or a list of nodes joined by commas is accepted.</li>
+</ul>
+<p>When multiple nodes are specified to the
+roundup get or roundup set
+commands, the specified properties are retrieved or set
+on all the listed nodes.</p>
+<p>When multiple results are returned by the roundup get
+or roundup find commands, they are printed one per
+line (default) or joined by commas (with the -list) option.</p>
+</div>
+<div class="section" id="usage-example" name="usage-example">
+<h2><a class="toc-backref" href="#id25">Usage Example</a></h2>
+<p>To find all messages regarding in-progress issues that
+contain the word "spam", for example, you could execute the
+following command from the directory where the database
+dumps its files:</p>
+<pre class="literal-block">shell% for issue in `roundup find issue status=in-progress`; do
+> grep -l spam `roundup get $issue messages`
+> done
+msg23
+msg49
+msg50
+msg61
+shell%</pre>
+<p>Or, using the -list option, this can be written as a single command:</p>
+<pre class="literal-block">shell% grep -l spam `roundup get \
+ \`roundup find -list issue status=in-progress\` messages`
+msg23
+msg49
+msg50
+msg61
+shell%</pre>
+</div>
+</div>
+<div class="section" id="e-mail-user-interface" name="e-mail-user-interface">
+<h1><a class="toc-backref" href="#id26">E-mail User Interface</a></h1>
+<p>The Roundup system must be assigned an e-mail address
+at which to receive mail. Messages should be piped to
+the Roundup mail-handling script by the mail delivery
+system (e.g. using an alias beginning with "|" for sendmail).</p>
+<div class="section" id="message-processing" name="message-processing">
+<h2><a class="toc-backref" href="#id27">Message Processing</a></h2>
+<p>Incoming messages are examined for multiple parts.
+In a multipart/mixed message or part, each subpart is
+extracted and examined. In a multipart/alternative
+message or part, we look for a text/plain subpart and
+ignore the other parts. The text/plain subparts are
+assembled to form the textual body of the message, to
+be stored in the file associated with a "msg" class node.
+Any parts of other types are each stored in separate
+files and given "file" class nodes that are linked to
+the "msg" node.</p>
+<p>The "summary" property on message nodes is taken from
+the first non-quoting section in the message body.
+The message body is divided into sections by blank lines.
+Sections where the second and all subsequent lines begin
+with a ">" or "|" character are considered "quoting
+sections". The first line of the first non-quoting
+section becomes the summary of the message.</p>
+<p>All of the addresses in the To: and Cc: headers of the
+incoming message are looked up among the user nodes, and
+the corresponding users are placed in the "recipients"
+property on the new "msg" node. The address in the From:
+header similarly determines the "author" property of the
+new "msg" node.
+The default handling for
+addresses that don't have corresponding users is to create
+new users with no passwords and a username equal to the
+address. (The web interface does not permit logins for
+users with no passwords.) If we prefer to reject mail from
+outside sources, we can simply register an auditor on the
+"user" class that prevents the creation of user nodes with
+no passwords.</p>
+<p>The subject line of the incoming message is examined to
+determine whether the message is an attempt to create a new
+issue or to discuss an existing issue. A designator enclosed
+in square brackets is sought as the first thing on the
+subject line (after skipping any "Fwd:" or "Re:" prefixes).</p>
+<p>If an issue designator (class name and id number) is found
+there, the newly created "msg" node is added to the "messages"
+property for that issue, and any new "file" nodes are added to
+the "files" property for the issue.</p>
+<p>If just an issue class name is found there, we attempt to
+create a new issue of that class with its "messages" property
+initialized to contain the new "msg" node and its "files"
+property initialized to contain any new "file" nodes.</p>
+<p>Both cases may trigger detectors (in the first case we
+are calling the set() method to add the message to the
+issue's spool; in the second case we are calling the
+create() method to create a new node). If an auditor
+raises an exception, the original message is bounced back to
+the sender with the explanatory message given in the exception.</p>
+</div>
+<div class="section" id="nosy-lists" name="nosy-lists">
+<h2><a class="toc-backref" href="#id28">Nosy Lists</a></h2>
+<p>A standard detector is provided that watches for additions
+to the "messages" property. When a new message is added, the
+detector sends it to all the users on the "nosy" list for the
+issue that are not already on the "recipients" list of the
+message. Those users are then appended to the "recipients"
+property on the message, so multiple copies of a message
+are never sent to the same user. The journal recorded by
+the hyperdatabase on the "recipients" property then provides
+a log of when the message was sent to whom.</p>
+</div>
+<div class="section" id="setting-properties" name="setting-properties">
+<h2><a class="toc-backref" href="#id29">Setting Properties</a></h2>
+<p>The e-mail interface also provides a simple way to set
+properties on issues. At the end of the subject line,
+<tt class="literal">propname=value</tt> pairs can be
+specified in square brackets, using the same conventions
+as for the roundup <tt class="literal">set</tt> shell command.</p>
+</div>
+</div>
+<div class="section" id="web-user-interface" name="web-user-interface">
+<h1><a class="toc-backref" href="#id30">Web User Interface</a></h1>
+<p>The web interface is provided by a CGI script that can be
+run under any web server. A simple web server can easily be
+built on the standard CGIHTTPServer module, and
+should also be included in the distribution for quick
+out-of-the-box deployment.</p>
+<p>The user interface is constructed from a number of template
+files containing mostly HTML. Among the HTML tags in templates
+are interspersed some nonstandard tags, which we use as
+placeholders to be replaced by properties and their values.</p>
+<div class="section" id="views-and-view-specifiers" name="views-and-view-specifiers">
+<h2><a class="toc-backref" href="#id31">Views and View Specifiers</a></h2>
+<p>There are two main kinds of views: <em>index</em> views and <em>issue</em> views.
+An index view displays a list of issues of a particular class,
+optionally sorted and filtered as requested. An issue view
+presents the properties of a particular issue for editing
+and displays the message spool for the issue.</p>
+<p>A view specifier is a string that specifies
+all the options needed to construct a particular view.
+It goes after the URL to the Roundup CGI script or the
+web server to form the complete URL to a view. When the
+result of selecting a link or submitting a form takes
+the user to a new view, the Web browser should be redirected
+to a canonical location containing a complete view specifier
+so that the view can be bookmarked.</p>
+</div>
+<div class="section" id="displaying-properties" name="displaying-properties">
+<h2><a class="toc-backref" href="#id32">Displaying Properties</a></h2>
+<p>Properties appear in the user interface in three contexts:
+in indices, in editors, and as filters. For each type of
+property, there are several display possibilities. For example,
+in an index view, a string property may just be printed as
+a plain string, but in an editor view, that property should
+be displayed in an editable field.</p>
+<p>The display of a property is handled by functions in
+a displayers module. Each function accepts at
+least three standard arguments -- the database, class name,
+and node id -- and returns a chunk of HTML.</p>
+<p>Displayer functions are triggered by <display>
+tags in templates. The call attribute of the tag
+provides a Python expression for calling the displayer
+function. The three standard arguments are inserted in
+front of the arguments given. For example, the occurrence of:</p>
+<pre class="literal-block"><display call="plain('status', max=30)"></pre>
+<p>in a template triggers a call to:</p>
+<pre class="literal-block">plain(db, "issue", 13, "status", max=30)</pre>
+<p>when displaying issue 13 in the "issue" class. The displayer
+functions can accept extra arguments to further specify
+details about the widgets that should be generated. By defining new
+displayer functions, the user interface can be highly customized.</p>
+<p>Some of the standard displayer functions include:</p>
+<table frame="border" rules="all">
+<colgroup>
+<col colwidth="12%" />
+<col colwidth="88%" />
+</colgroup>
+<thead valign="bottom">
+<tr><th>Function</th>
+<th>Description</th>
+</tr>
+</thead>
+<tbody valign="top">
+<tr><td>plain</td>
+<td>display a String property directly;
+display a Date property in a specified time zone with an option
+to omit the time from the date stamp; for a Link or Multilink
+property, display the key strings of the linked nodes (or the
+ids if the linked class has no key property)</td>
+</tr>
+<tr><td>field</td>
+<td>display a property like the
+plain displayer above, but in a text field
+to be edited</td>
+</tr>
+<tr><td>menu</td>
+<td>for a Link property, display
+a menu of the available choices</td>
+</tr>
+<tr><td>link</td>
+<td>for a Link or Multilink property,
+display the names of the linked nodes, hyperlinked to the
+issue views on those nodes</td>
+</tr>
+<tr><td>count</td>
+<td>for a Multilink property, display
+a count of the number of links in the list</td>
+</tr>
+<tr><td>reldate</td>
+<td>display a Date property in terms
+of an interval relative to the current date (e.g. "+ 3w", "- 2d").</td>
+</tr>
+<tr><td>download</td>
+<td>show a Link("file") or Multilink("file")
+property using links that allow you to download files</td>
+</tr>
+<tr><td>checklist</td>
+<td>for a Link or Multilink property,
+display checkboxes for the available choices to permit filtering</td>
+</tr>
+</tbody>
+</table>
+</div>
+<div class="section" id="index-views" name="index-views">
+<h2><a class="toc-backref" href="#id33">Index Views</a></h2>
+<p>An index view contains two sections: a filter section
+and an index section.
+The filter section provides some widgets for selecting
+which issues appear in the index. The index section is
+a table of issues.</p>
+<div class="section" id="index-view-specifiers" name="index-view-specifiers">
+<h3><a class="toc-backref" href="#id34">Index View Specifiers</a></h3>
+<p>An index view specifier looks like this (whitespace
+has been added for clarity):</p>
+<pre class="literal-block">/issue?status=unread,in-progress,resolved&amp;
+ topic=security,ui&amp;
+ :group=+priority&amp;
+ :sort=-activity&amp;
+ :filters=status,topic&amp;
+ :columns=title,status,fixer</pre>
+<p>The index view is determined by two parts of the
+specifier: the layout part and the filter part.
+The layout part consists of the query parameters that
+begin with colons, and it determines the way that the
+properties of selected nodes are displayed.
+The filter part consists of all the other query parameters,
+and it determines the criteria by which nodes
+are selected for display.</p>
+<p>The filter part is interactively manipulated with
+the form widgets displayed in the filter section. The
+layout part is interactively manipulated by clicking
+on the column headings in the table.</p>
+<p>The filter part selects the union of the
+sets of issues with values matching any specified Link
+properties and the intersection of the sets
+of issues with values matching any specified Multilink
+properties.</p>
+<p>The example specifies an index of "issue" nodes.
+Only issues with a "status" of either
+"unread" or "in-progres" or "resolved" are displayed,
+and only issues with "topic" values including both
+"security" and "ui" are displayed. The issues
+are grouped by priority, arranged in ascending order;
+and within groups, sorted by activity, arranged in
+descending order. The filter section shows filters
+for the "status" and "topic" properties, and the
+table includes columns for the "title", "status", and
+"fixer" properties.</p>
+<p>Associated with each issue class is a default
+layout specifier. The layout specifier in the above
+example is the default layout to be provided with
+the default bug-tracker schema described above in
+section 4.4.</p>
+</div>
+<div class="section" id="filter-section" name="filter-section">
+<h3><a class="toc-backref" href="#id35">Filter Section</a></h3>
+<p>The template for a filter section provides the
+filtering widgets at the top of the index view.
+Fragments enclosed in <tt class="literal"><property>...</property></tt>
+tags are included or omitted depending on whether the
+view specifier requests a filter for a particular property.</p>
+<p>Here's a simple example of a filter template:</p>
+<pre class="literal-block"><property name=status>
+ <display call="checklist('status')">
+</property>
+<br>
+<property name=priority>
+ <display call="checklist('priority')">
+</property>
+<br>
+<property name=fixer>
+ <display call="menu('fixer')">
+</property></pre>
+</div>
+<div class="section" id="index-section" name="index-section">
+<h3><a class="toc-backref" href="#id36">Index Section</a></h3>
+<p>The template for an index section describes one row of
+the index table.
+Fragments enclosed in <tt class="literal"><property>...</property></tt>
+tags are included or omitted depending on whether the
+view specifier requests a column for a particular property.
+The table cells should contain <display> tags
+to display the values of the issue's properties.</p>
+<p>Here's a simple example of an index template:</p>
+<pre class="literal-block"><tr>
+ <property name=title>
+ <td><display call="plain('title', max=50)"></td>
+ </property>
+ <property name=status>
+ <td><display call="plain('status')"></td>
+ </property>
+ <property name=fixer>
+ <td><display call="plain('fixer')"></td>
+ </property>
+</tr></pre>
+</div>
+<div class="section" id="sorting" name="sorting">
+<h3><a class="toc-backref" href="#id37">Sorting</a></h3>
+<p>String and Date values are sorted in the natural way.
+Link properties are sorted according to the value of the
+"order" property on the linked nodes if it is present; or
+otherwise on the key string of the linked nodes; or
+finally on the node ids. Multilink properties are
+sorted according to how many links are present.</p>
+</div>
+</div>
+<div class="section" id="issue-views" name="issue-views">
+<h2><a class="toc-backref" href="#id38">Issue Views</a></h2>
+<p>An issue view contains an editor section and a spool section.
+At the top of an issue view, links to superseding and superseded
+issues are always displayed.</p>
+<div class="section" id="issue-view-specifiers" name="issue-view-specifiers">
+<h3><a class="toc-backref" href="#id39">Issue View Specifiers</a></h3>
+<p>An issue view specifier is simply the issue's designator:</p>
+<pre class="literal-block">/patch23</pre>
+</div>
+<div class="section" id="editor-section" name="editor-section">
+<h3><a class="toc-backref" href="#id40">Editor Section</a></h3>
+<p>The editor section is generated from a template
+containing <display> tags to insert
+the appropriate widgets for editing properties.</p>
+<p>Here's an example of a basic editor template:</p>
+<pre class="literal-block"><table>
+<tr>
+ <td colspan=2>
+ <display call="field('title', size=60)">
+ </td>
+</tr>
+<tr>
+ <td>
+ <display call="field('fixer', size=30)">
+ </td>
+ <td>
+ <display call="menu('status')>
+ </td>
+</tr>
+<tr>
+ <td>
+ <display call="field('nosy', size=30)">
+ </td>
+ <td>
+ <display call="menu('priority')>
+ </td>
+</tr>
+<tr>
+ <td colspan=2>
+ <display call="note()">
+ </td>
+</tr>
+</table></pre>
+<p>As shown in the example, the editor template can also
+request the display of a "note" field, which is a
+text area for entering a note to go along with a change.</p>
+<p>When a change is submitted, the system automatically
+generates a message describing the changed properties.
+The message displays all of the property values on the
+issue and indicates which ones have changed.
+An example of such a message might be this:</p>
+<pre class="literal-block">title: Polly Parrot is dead
+priority: critical
+status: unread -> in-progress
+fixer: (none)
+keywords: parrot,plumage,perch,nailed,dead</pre>
+<p>If a note is given in the "note" field, the note is
+appended to the description. The message is then added
+to the issue's message spool (thus triggering the standard
+detector to react by sending out this message to the nosy list).</p>
+</div>
+<div class="section" id="spool-section" name="spool-section">
+<h3><a class="toc-backref" href="#id41">Spool Section</a></h3>
+<p>The spool section lists messages in the issue's "messages"
+property. The index of messages displays the "date", "author",
+and "summary" properties on the message nodes, and selecting a
+message takes you to its content.</p>
+</div>
+</div>
+</div>
+<div class="section" id="deployment-scenarios" name="deployment-scenarios">
+<h1><a class="toc-backref" href="#id42">Deployment Scenarios</a></h1>
+<p>The design described above should be general enough
+to permit the use of Roundup for bug tracking, managing
+projects, managing patches, or holding discussions. By
+using nodes of multiple types, one could deploy a system
+that maintains requirement specifications, catalogs bugs,
+and manages submitted patches, where patches could be
+linked to the bugs and requirements they address.</p>
+</div>
+<div class="section" id="acknowledgements" name="acknowledgements">
+<h1><a class="toc-backref" href="#id43">Acknowledgements</a></h1>
+<p>My thanks are due to Christy Heyl for
+reviewing and contributing suggestions to this paper
+and motivating me to get it done, and to
+Jesse Vincent, Mark Miller, Christopher Simons,
+Jeff Dunmall, Wayne Gramlich, and Dean Tribble for
+their assistance with the first-round submission.</p>
+</div>
+<div class="section" id="changes-to-this-document" name="changes-to-this-document">
+<h1><a class="toc-backref" href="#id44">Changes to this document</a></h1>
+<ul class="simple">
+<li>Added Boolean and Number types</li>
+<li>Added section Hyperdatabase Implementations</li>
+<li>"Item" has been renamed to "Issue" to account for the more specific nature
+of the Class.</li>
+</ul>
+</div>
+</div>
+<hr class="footer"/>
+<div class="footer">
+Generated on: 2002-07-29. </div>
+</body>
+</html>