Extension:DynamicPageList (third-party)

NOTE : Since the last publication of DPL by the author several useful changes have been made in the SVN system. These changes are not included in DPL 2.0. They will be re-merged into that revision, however, within the next weeks. Also the security risk of manipulating files in the dpl-cache described above will be eliminated soon.


 * This is a third-party extension, not to be confused with the DynamicPageList used on Wikimedia sites.

DynamicPageList (DPL) is a reporting tool for MediaWiki, listing category members and intersections with various formats and details. For full documentation, see the manual (German Manual Hilfe:DynamicPageList).

In its most basic form, DPL displays a list of pages in one or more categories. Selections may also be based on factors such as author, namespace, date, name pattern, usage of templates or references to other articles. Output takes a variety of forms, some of which incorporate elements of selected articles.

This extension is invoked with the parser function  or parser tag. A Wikimedia-compatible implementation of certain features can be invoked with.

DPL can result in computationally-expensive database queries. For best performance, use the optional parameters allowcachedresults and/or dplcache where possible.

Installation
The extended dynamic page list (DPL) is now in Wikimedia's SVN. To install: LocalSettings.php must not include Wikimedia's version of DPL (Intersection). If you want to run them in parallel, include DynamicPageListMigration.php instead to prevent this extension from overriding.
 * download the extension files for your version of MediaWiki, and place them in the  directory
 * add  to LocalSettings.php
 * set overrides for DPL configuration variables, if desired

Configuration
DPL configuration settings and their default values, from the manual:

The global variable is also respected by DPL. It will prevent the contents of the listed namespaces from appearing in DPL's output.
 * || 500
 * ||  for &lt;dpl&gt; but   for &lt;DynamicPageList&gt;. If set to 'true' DPL will no longer behave dynamically because its output is taken from the ParserCache.
 * || no options
 * || 4  
 * colspan=2|
 * }
 * || 500
 * ||  for &lt;dpl&gt; but   for &lt;DynamicPageList&gt;. If set to 'true' DPL will no longer behave dynamically because its output is taken from the ParserCache.
 * || no options
 * || 4  
 * colspan=2|
 * }
 * ||  for &lt;dpl&gt; but   for &lt;DynamicPageList&gt;. If set to 'true' DPL will no longer behave dynamically because its output is taken from the ParserCache.
 * || no options
 * || 4  
 * colspan=2|
 * }
 * colspan=2|
 * }
 * }

'Note:  is a LIMIT on the SQL query itself''. Some DPL query parameters like  are applied after the SQL query, however, so results here may easily be misleading.'''

Functional richness
DynamicPageList has many features; some are expensive, or dangerous in the wrong hands. It is important to choose an appropriate level of functionality for your wiki.


 * is equivalent to Wikimedia's DPL
 * adds additional formatting parameters
 * adds performance equivalent features for templates and pagelinks
 * allows more-expensive page inclusion features and regular expression queries; expect to use the dplcache parameter
 * permits exotic and potentially dangerous batch update and delete operations; not recommended for public websites

'''Note: Functional Richness parameters have been removed in the latest versions of the extension. There is no function for setting functional richness in these versions.'''

Extended DPL functionality
Extended DPL is invoked by using the parser function, or the parser extension tag.


 * See: Manual - General Usage and Invocation Syntax and Manual - DPL parameters

Backwards-compatible functionality
Functionality compatible with Wikimedia's DPL extension can be invoked with.
 * See: Extension:DynamicPageList (Wikimedia)

Overview
Assume you have written some articles about countries. Typically these articles will have three things in common:
 * They will belong to a common category
 * They will have a similar chapter structure, i.e. they will contain paragraphs named 'Religion' or 'History'
 * They will use a template which is used to present highly structured short data items ('Capital', 'Inhabitants', ..) in a nice way (e.g. as a wikitable)

DPL generates reports on articles
Let us assume that there is an article on Islam. You want to give some information about the spreading of this religion over various countries. But you do not want to create redundancy by repeating information that was already given in the articles on the countries.

In our scenario the natural approach with DPL would be to generate a list of 'countries' (=category) where Islam plays a role (i.e. restrict your selection to articles of category 'Country' which contain a link to 'Islam'). Typically you would want to include part of the text chapter on 'Religion' from each of the relevant countries. You might also want to give the number of inhabitants for each country. The output should be shown as an alphabetically ordered table. It would be nice if the user could easily sort the table by inhabitants or some other criteria.

With DPL you can ..


 * generate a list of all those articles (or a random sample)
 * show metadata of the articles (popularity, date of last update, ..)
 * show one or more chapters of the articles ('transclude' content)
 * show parameter values which are passed to the common template
 * order articles appropriately
 * present the result in a sortable table (e.g.)
 * use multi column output

Which steps are necessary?
Find the articles you want to list:
 * select by a logical combination (AND,OR,NOT) of categories
 * specify a range for the number of categories the article must be assigned to
 * select by a logical combination (AND,OR,NOT) of namespaces
 * define a pattern which must match the article´s name
 * name a page to which the article must or must not refer
 * name a template which the article must or must not use
 * name a text pattern which must occur within external links from a page
 * exclude or include redirections
 * restrict your search to stable pages or quality pages ("flagged revisions")
 * use other criteria for selection like author, date of last change etc.
 * define regular expressions to match the contents of pages you want to include

Order the result list of articles according to
 * name
 * date of last change
 * popularity
 * user who changed them last
 * size
 * restrict the output to the first n articles or to a random sample
 * use descending or ascending sequence

Define attributes you want to see
 * article name
 * article namespace
 * article size
 * date of last change
 * date of last access
 * user who changed them last

Define contents you want to show
 * whole article
 * contents of certain chapters (identified by headings)
 * text portions (defined by special marker tags in the article)
 * values of template calls
 * substitute the original template by a different one and show the output of that template

Define the output format
 * specify headline and footer for your report
 * use ordered list, unordered list
 * use tables, sorted tables (using javascript)
 * format table fields individually by applying templates to their content
 * use category style listing
 * create "tag clouds" by varying output text size depending on popularity of pages
 * multi column output
 * truncate title or contents to a certain maximum length
 * add a link to the article or to one or more of its chapters

DPL generates reports on categories
Apart from producing a list of pages which match certain criteria, DPL can also create a list of categories a selected set of pages belongs to. This can be useful to get an idea of the semantic scope of a group of pages (which can be defined by some arbitrary criteria). One of the more useful applications would be question like: "To which categories do the pages belong which contain a reference to the current page?"

DPL can be used for bulk editing
Sometimes you want to perform a similar editing task on many articles (like adding a template at the beginning of the text). DPL has a feature which allows you to update other articles based on regular expressions. This feature is experimental and can be disabled in the DPL config file.

DPL extracts objects and relations for generation of graphs with Extension:Wgraph
With DPL you can generate output which is then fed into other MediaWiki extensions. An especially useful application of this kind is graph generation. DPL can analyze your wiki and prepare output which is then used by Extension:Wgraph to visualize it.

DPL interacts with other extensions
There is a special mechanism which allows you to call your own extension inside the result loop of a DPL query. This opens doors for assembling new 'applications' without having to program on php level. For example you can create menu trees for Extension:Treeview, you can create dependency graphs or timebars with Extension:Wgraph, you can generate nice bar graphs or pie charts using DPL together with Ploticus, you can call 'gallery' or whatever you want...

DPL is a platform for building other applications
The power of DPL makes it possible to create applications on wiki template level which would normally require PHP programming.
 * See for example the Extension:DPL Calendar. The advantage is that these applications can be more easily modified and localized.
 * Another example is a light-weight "semantic wiki" approach. See the DPL demo page for details.

DPL and performance
With a few lines of DPL code it is possible to create huge output and CPU load (think of a DPL query which tries to include the contents of all articles in your mediawiki ;-)). Normally this is not a problem because users who write DPL queries have some level of expertise. If you are afraid, however, you can restrict the execution of DPL queries to protected articles.

Apart from that the general performance of DPL on medium-size wikis is quite acceptable (see the performance tests on the dpldemo website). Use of allowcachedresults and/or dplcache where possible can improve performance.

MediaWiki SVN Version of DPL2
The instructions on this page were written for the code that is available from http://semeb.com/dpldemo/Download and is different than the version available in MediaWiki's SVN. Some of the differences include:
 * There is not a  tag, just a DPL and section tag.
 * There is no setFunctionalRichness function.
 * The main class is named ExtDynamicPageList2 and not ExtDynamicPageList.

Call extension
The website where DPL is offered for download also contains the Call extension which allows to call an arbitrary MediaWiki article from the command line or from a wiki link and pass parameters to that article at the same time.

Other applications

 * DPL Page Name S/N Maker-Use this extension to create pages with serial number page names

Comparisons

 * Comparison of Dynamic Pagelist x Semantic Mediawiki

Related extensions

 * BackLinksFunctions counts backlinks
 * News creates reports on page changes
 * Semantic MediaWiki turns links and data in wiki pages into queryable information
 * TemplateTable creates tables from template fields
 * Ploticus can be used to create charts from DPL query results
 * Wgraph creates graphs from DPL output
 * Extension:Todo Tasks creates/maintains todo tasks and notifies users to whom the task is assigned
 * Extension:DPL Calendar a highly configurable calendar
 * Extension:CategoryLink Creates a table of the wiki's categories

Older versions of this extension

 * Extension:DynamicPageList2 (older version)
 * Extension:DynamicPageList (Wikimedia) (the one used on Wikinews and Wikibooks. Note this extension is a fork of the other extension, and not exactly an older version)