Extension inventory

This page serves to inventory and assess the mix of extensions that are in use for the DCS wiki:

Regular

Code for "regular" extensions are hosted on Gerrit at the WMF (which is also mirrored to GitHub) with documentation at https://www.mediawiki.org/wiki. Regular is in quotes because all extensions modify the behavior and capabilities of MediaWiki. Those that are used by the WMF in their projects or are distributed in the official download should be considered stable, tested, and maintained. Over time, some extensions become part of MediaWiki core; and rarely core features are extracted into extensions.

DCS Custom

Code for the DCS extensions is in the private Debt Compliance GitHub repo

Organic Design

Organic Design extensions are in the 'MediaWiki' tree of the Organic Design GitHub repo. Just because it's an OD extension doesn't mean it's not used by the wider MediaWiki community. We try to note usage below.

The ultimate goal is two-fold: not only understand 'What does it do?', but also understand related questions like:

• "How critical is it? (Used all the time / occasionally, but still essential / never)"
• "Does it need work? (known bugs or missing functionality)"
• "Can or should this extension be replaced (with a more widely supported "regular" extension) to improve maintainability, features, security and lower cost?

Of course some features or functions are not really "user-centric" but might provide security or other features important to stakeholders like "Owner" or "Developer". For example: The DcsSkin provides a look and feel that is consistent with the company brand and makes the user experience more seamless while navigating between Website / Rails App / Wiki.

I've put information about "Source lines of code" into a sub-article.

#	Extension	What does it do? (explain functionality by role: regular-user, talk-editor, client-admin, or sysop)	Maintenance / Last release	Used by WMF	Used by Meza	Used by QualityBox	Example / Notes / Alternatives?
1	CirrusSearch	Extends the core search for MediaWiki to be able to use Elasticsearch. Elasticsearch provides a much better search capability to all users of the wiki. In particular, it allows DCS to index documents (file uploads).	Continuous	Yes	Yes	Yes	CirrusSearch (Elasticsearch) is vital to the ability to index uploaded files
2	Elastica	Base Elasticsearch functionality by providing the Elastica library; required by CirrusSearch.	Continuous	Yes	Yes	Yes	Required as part of Search
3	Nuke	The Nuke extension makes it possible for sysops to mass delete pages.	Continuous	Bundled	No	Yes	For whatever reason, the DCSNuke extension intercepts page requests for the Nuke special page. DCSNuke has no added functionality. The DCSNuke code is roughly equivalent to the REL1_20 release of Nuke; and the current Nuke extension offers more functionality. I thought that potentially the reason to use a cloned extension was to totally customize the interface language strings, but that's not the case. Remove DCSNuke. DcsNuke is not just a clone, as described in the Github wiki Extensions page: it adds a new field for supplying a title pattern to select the deletion candidates by. Other criteria could be added later such as restricting to category. The custom DcsNuke extension does not provide features different from the regular Nuke extension. The regular Nuke extension shall be included for DCS.
4	ParserFunctions	Enhances the wikitext parser with helpful functions, mostly related to logic and string-handling.	Continuous maintenance	Bundled	Yes	Yes	At the bottom of the Special:Version page, you'll see a list of "Parser Function Hooks" that includes the following custom parser functions defined by DCS extensions: amendments, companycomments, compliancechecklist, loans, loansinuse, section. Many of the others are provided by the Parser Functions extension: if, ifeq, switch, ifexist, ifexpr, iferror, time, timel, expr, rel2abs, titleparts, len, pos, rpos, sub, count, replace, explode
5	PipeEscape	The Pipe Escape extension allows for pipe characters in parser function arguments (and template argument calls) avoid being interpreted as an argument delimiter. This is primarily for the purpose of using wiki tables (or parts thereof) inside parser function calls or templates.	Old but stable	Bundled	Yes	Yes	Included via DcsSetup
6	SimpleMathJax	The SimpleMathJax extension enables MathJax, a Javascript library, for typesetting TeX formula in MediaWiki inside math environments. This extension will load resources from cdnjs.cloudflare.com on all wiki pages that have math or chem tags.	Regular maintenance	No, WMF uses the Math extension	Yes	Yes	included by DcsSetup.php
7	WikiEditor	The WikiEditor extension provides an improved interface for editing wikitext. It is the wikitext editing interface that Wikipedia started using in 2010 for desktop users, and so it is sometimes called the "2010 wikitext editor".	0.5.1 (2016-04-15) some oversight by WMF	Bundled	Yes	Yes
8	DcsAmmendments	Adds ammendments section to DCS loan pages. Sysop (only) can add/delete/edit/re-order (up/down) the ammendments; UX implemented in JavaScript. Extends the API with the same functions. Adds new log type: amendments; and logs all actions.	Jan 2018 - new sort functionality ready for testing	no	no	no	https://clienttest.dm.dcstemporary.com/ARCA14:1.5_Time_References
9	DcsBaskets	This extension allows the utilization column of the Baskets tables to be edited directly using AJAX and saving values into 'basket' tables rather than in the traditional wiki-text revision tables.	1.4.3, 2018-05-25	no	no	no	"Baskets" can be found in the hierarchy list of the leftnav under the 'Compliance' folder. The page name, by convention, is 'Baskets' e.g. https://clienttest.dm.dcstemporary.com/Baskets This is really neat, and very advanced. However, now that Visual Editor is available, I'd suspect that the user experience of editing large tables in Visual Editor would be much better. Replace Baskets with Visual Editor We've tested the Visual Editor and found it to be to "clunky" for practical use, that was a year or so back, but based on my own experience I think it would still be considered that way if it was tested again now
10	DcsCommon	Cookie handling was added on June 14, 2017. The code (the cookie.js part) is from a project called js-cookie. So, we could update that code. Or, we could replace it with internal functions so we don't rely on 3rd party code. See the API documentation for mw.cookie (Does not use the $wgCookieSecure configuration variable since 'detect' could not work with ResourceLoaderStartUpModule; as module cache is not fragmented by protocol.) The mw.cookie (JavaScript) code is syntactically and functionally similar to the server-side cookie API (`WebRequest#getCookie` and `WebResponse#setcookie`). https://www.mediawiki.org/wiki/Manual:Hooks/UserSetCookies is deprecated as of REL1_27, and session-handling extensions should be subclassing CookieSessionProvider. $wgSessionProviders The class creates methods for outputting messages, notices, dates, getting raw content. It loads some javascript (through resource loader). That javascript could more easily be maintained as MediaWiki:Common.js? although there may be load order issues. The JS defines like-named methods with varying features. E.g. Check if the passed page title string is in a loan namespace, returns boolean. Note that this function only checks if the namespace is in the list of all loan namespaces, it doesn't do any checks for whether the namespace is in use, or whether the title is in a DCS_TOC article like the DcsCommon::isLoanPage PHP function. The series of extensions create DcsInit() (in DcsEmailLink), DcsBlockPageAccess(), and DcsReady() hook functions. DcsReady() implementations are different across different classes from Basket to DcsSingleSignOn. The 'common' extension creates a singleton instance of the DcsCommon class that does a bunch of things according to notes in the wiki. The permissions shouldn't really be hidden away in the class code. They should simply be in LocalSettings.php. onUserGetRights() is a big function. The 'self:cache' is mostly called in connection with 'isLocal'. Any true caching should just be offloaded to APC and memcache. Although there is no 'dcs' table in the database on dcsTemporary, the setData() method is used throughout the codebase so should update wiki about where this data is stored. set/getData is for storing arbitrary DCS data in the dcs db table. Agreed that this extension needs cleaning up.	recent	no	no	no	pervasive
11	DcsComplianceChecklist	Provides a dropdown list of loans and responsibility terms by which the table can be filtered on the Checklist page (by convention). The parser function creates the page contents and form controls.	recent (2017 - 2018)	no	no	no	e.g. https://clienttest.dm.dcstemporary.com/Checklist
12	DcsComplianceChecklist2	purpose?	release?	no	no	no	only used in the checktest subdomain, or when `wgLocalTesting`; intention is to use a timestamp condition. This is in progress, the requirements of the checklist are simpler now and version 2 is just about stripping out a bunch of obsolete functionality.
13	DcsEmailLink	Allows you to send a link to a page in the wiki. Activated by the "Email Link" item in the primary navigation across the top of the page. Similar to the "Email Page" extension by Aran, which is also used.	11 months ago	no	no	no	visit any page
14	DcsExportTerms	Allows terms to be downloaded in Comma Separated Value (CSV) format. CSV is easily imported to a spreadsheet.	recent	no	no	no	Visit https://clienttest.dm.dcstemporary.com/Category:Terms and you will see a "Export Terms" action in the primary navigation across the top of the page.
15	DcsFindTitle	helps to find a title regardless of case-sensitivity of the system.	recent	no	no	no	integrates with the API, however I'm unsure where it's visible/usable to the user. I believe it's used from the Ruby side to create links that will match a wiki page even if there is a case mismatch. If you wish to navigate to https://clienttest.dm.dcstemporary.com/ARCA14:TOC but request https://clienttest.dm.dcstemporary.com/arca14:toc instead, you'll get a 404 Not Found error. If you request https://clienttest.dm.dcstemporary.com/arca14:toc?action=findtitle then you will be redirected to the proper article. This uses ApiBeforeMain and APIAfterExecute hooks to modify the API query prop=info to make it case-insensitive.
16	DcsGroupAdmin	Leverages the DcsBlockPageAccess hook to allow/disallow access to files and namespaces.	recent	no	no	no	https://clienttest.dm.dcstemporary.com/Special:DcsGroupAdmin/equality
17	DcsJobAdmin	See Background info on Background jobs. Creates a Special Page Special:DcsJobAdmin where you can start a new job; or view current and historical jobs. Each job type loads it's own form into the Admin page. The job runner extends the Maintenance class, and loops over running jobs to provide some progress reporting. It saves the most recent 10 jobs to a 'history' list. There are functions in the code for: Return a list of the currently running jobs sorted by start time. Add a job to the 'history' list of jobs executed (list is limited to 10 items). Get a 'history' list of the last 10 jobs Get job data (both current and history) shell_exec() to the process table to find DcsJobRunner. Return the currently running jobs by Process ID (PID) register the PHP code classes for each job type: Change Namespace EditTest Import ImportXML Links PhpTest ReplaceText UpgradeAttachments Each (or almost all?) PHP file is backed by a perl file which was the basis for the PHP development. Everything is written twice because it all started back when the best framework for handling MediaWiki jobs was a perl bot framework. Things have changed significantly over the recent past for MediaWiki's job queue. According to the documentation, it allows you to manage jobs. But, I'm wondering how much this is actually used? The job queue should be run automatically by cron, and the administrative user shouldn't have to worry about it really. If there is a usage pattern where job execution is time sensitive, there is a use for an Admin function; but I'm curious about the usage patterns that create large or numerous jobs. Otherwise, set wgJobRunRate to zero, and put it into cron `0 0 * * * root /usr/bin/php /var/www/example.com/www/w/maintenance/runJobs.php > /var/log/runJobs.log 2>&1` These jobs aren't just the standard MW maintenance jobs, they're DCS-specific jobs that need to run in the background as they often need to do intensive manipulation of thousands of articles. The special page is the interface to these jobs allowing parameters to be set for them and stopping/starting/cancelling/pausing them etc, as well as getting feedback on their progress or errors etc.	2018-05-25	no	no	no
18	DcsLoanPages	creates "backlinks" which are links to content that contain a particular keyword or phrase found in a loan document. It also creates the "< Prev" and "Next >" navigation links (called 'breadcrumbs' in the code, but actually these are 'pager' links not breadcrumbs).	recent	no	no	no	If you go to a page like https://clienttest.dm.dcstemporary.com/ARCA14:Agreement You will see a large section of content called 'Index to ARCA14 pages containing "Agreement"" So, in other words, it's a list of links to pages of the ARCA14 loan that have the word "Agreement" in them. These links are created by the extension. They wanted the backlinks at the bottom of the page not in a separate special page
19	DcsNamespaces	Manages the segregation of loan documents into their own separate namespaces. Also provides some functionality around moving/deleting/renaming namespaces via the https://clienttest.dm.dcstemporary.com/Special:DcsNamespaces special page.	recent	no	no	no	e.g. https://clienttest.dm.dcstemporary.com/Special:DcsNamespaces
20	DcsNuke	purpose?	release?	no	no	no	REPLACE with standard Nuke extension See notes in Nuke above, this is not a replica of Nuke
21	DcsSearch	Extends the Elasticsearch backend with additional business logic, and new features and UX (saving search "favorites" and indexing link paths traversed in connection with a search query). See https://github.com/debtcompliance/mediawiki/wiki/Search-&-sorting	a year ago	no	no	no	e.g. See the "heart" symbol next to the search box which implements the "favorites" feature.
22	DcsSection	Allows for loan documents to be imported into the wiki as multiple articles. Creates a 'section reference' capability.	in progress (v2)	no	no	no
23	DcsSection2	purpose?	release?	no	no	no	Unused - at least not on the development machine which is a clone of production. There is a lot of obsolete and patched functionality in this extension, a version 2 was about to be started to strip all this out
24	DcsSingleSignOn	Create a master/slave relationship with the Ruby on Rails application as the authentication and group mangement source; with the MediaWiki application synchronizing user information into it's local database.	2017 major update	no	no	no	For testing, you can access /wiki/extensions/dcs/DcsSingleSignOn/testLogin.php
25	DcsSkin	Custom 'style' to match DCS website / frontend QAR app	3.0.2, 2016-07-01	no	no	no	Skin by Aran Dunkley
26	DcsTitle	Extends the regular MediaWiki title object class. Creates a custom cache of the TOC.	recent	no	no	no	yes
27	DcsUploadedFiles	Creates a special page listing all the files uploaded to loan documents orderd by loan namepsace then by article	a year ago	no	no	no	https://clienttest.dm.dcstemporary.com/Special:DcsUploadedFiles
28	DcsUserDisable	Adds 'enable/disable' links to the User list	a year ago	no	no	no	https://clienttest.dm.dcstemporary.com/Special:ListUsers Why not use the Special:Block functionality built into core?I believe it's every bit as accessible through the API and thus could be used from QAR.
29	DcsWatchComments	Adds subscription to talk pages.	release?	no	no	no	When I view my normal MediaWiki 'WatchList', I don't see any loan talk pages added. I only see my user page. This functionality doesn't apply to the MW watchlist, it's on the Company Comments page
30	AjaxComments
31	EmailPage	Adds a special page that allows you to send the rendered HTML contents of a wiki page to a recipient (or list). Dependant on PHPMailer (5.2.23)	2.4.4 (2017-04-26)	Used by at least 38 wikis	no	no	Activated by the "Email" item in the primary navigation across the top of the page.
32	ExtraMagic	Adds extra Magic Words and Parser functions.
33	jQueryUpload		v1.4.5, 2016-08-28		no	no
34	PdfBook	The PdfBook extension composes a book from articles in a category, bullet list, or DPL query; and exports as a PDF file. Depends on HTMLDoc	1.5.1 (2017-05-14)	Used by at least 154 wikis	no	no
35	TreeAndMenu	Makes bullet lists into folder trees or dynamic drop-down menus. The drop-down menu functionality uses Son of Suckerfish which is 99% CSS, and the tree component is now using the FancyTree jQuery plugin rather than the dTree used in previous version of the TreeAndMenu extension. The new FancyTree has many options and plugins and is very extendable, please view the site and examples for more detail.	4.2.2 (2018-01-31)	Used by at least 137 wikis	no	no

Double Check

You can visit the "Special:Version" page of the wiki. This page shows you exactly what extensions and versions of software are installed and activated on your wiki.

WikiMedia Foundation = the organization which runs various projects including Wikipedia.org

Application Programming Interface

Asynchronous JavaScript and XML = A means to exchange data with a server without loading a whole new page.

JavaScript = A computer language.

PHP is the HyperText Preprocessor = the most popular programming language for the web

HyperText Markup Language = structured text that uses logical links (hyperlinks) between nodes containing text.

Dynamic Page Lists = Like a Cuisinart food processor, it allows you to slice and dice the contents of your wiki.

Portable Document Format = a widely used standard for representing documents electronically and print. PDF

Cascading Style Sheets = A technology that deals with the presentation of content on the web