Help:DPL3/Parameters: Other parameters

updaterules
Syntax:

updaterules= rule; ...    rule;

Where rule is one of the following:

replace pattern; by    replacement; before pattern; insert text; after  pattern; insert text;
 * rules for batch update of articles

template template name; legend   legend article name; table    table format; editform form parameters; action   form action; hidden   value; submit   submit button; commit   commit button; parameter parameter name; value    value; format   display format; tooltip  text; optional value; afterparm parameter name;
 * rules for interactive update of articles

summary edit summary text; exec   value;
 * common rules

The first group of rules is intended for batch updates of articles. A DPL query can select a group of articles and perform updates like inserting a piece of text at a certain position or changing text portions based on regular expressions.

The second group of rules is intended for interactive form-based editing of template values.

The third group of rules is common to both other groups and controls the update process.

The  feature is intended for wiki expert users only. It is recommended that articles using this statement are 'protected':

replace pattern;
Defines a regular expression which matches text portions that shall be replaced. It is in the responsibility of the user to provide enclosing characters for the regexp; modifiers line 'U' or 'm' can be used.

by replacement;
Defines the replacement for the above pattern; back references like \1 can be used.

before pattern;
Defines locations where text will be inserted. The location(s) will be immediately before the match(es) of the pattern. If a pattern matches multiple times, multiple inserts will be performed.

The regexp will implicitly be enclosed in slashes. Hence literal slash characters must be escaped by backslashes.

after pattern;
Defines locations where text will be inserted. The location(s) will be immediately after the match(es) of the pattern. If a pattern matches multiple times, multiple inserts will be performed.

The regexp will implicitly be enclosed in slashes. Hence literal slash characters must be escaped by backslashes.

insert text;
Defines the text to be inserted.

A DPL statement may contain replacement, insertion before and after at the same time. replace /([a-z]+])-cat/; by     \1-dog; before foo; insert bar; after  foo; insert bar2;

Only one 'replace'-'by' sequence, one insertion 'before' and one insertion 'after' can be specified. 'replace' is always executed first, followed by 'insert before' and 'insert after', regardless of the sequence in which the rules appear in the DPL source ´text.

template template name;
The name of the template; the prefix "Template:" must be given.

be inserted. The location(s) will be immediately before the match(es) of the pattern. If a pattern matches multiple times, multiple inserts will be performed.

The regexp will implicitly be enclosed in slashes. Hence literal slash characters must be escaped by backslashes.

a regular expression after  pattern; insert text; replace pattern; by     replacement;

For safety reasons the update statements will only be performed if "exec yes" is specified. So, leaving this away, you can check what would happen if the update were to be executed.

Note that if "exec yes" is present the update will be performed each time the page is rendered which contains the DPL statement with the. So it is advisable to set "exec yes" only via a command line argument and not as part of the statioc article text. Thus you stay in control when the update happens. Typically one would use an URL parameter like DPL_arg1 for that purpose.

The size of the form fields will dapt to the size of the displayed content.

text is plain text; replacement is text which may contain references (like \1) to the matching pattern (provided that this pattern contains match groups).

deleterules
deleterules= reason text; exec  true;

This command is experimental at the moment.

This will delete the selected pages; If "exec true" is missing, nothing will happen.

goal
Syntax:

Explanation:

Default is 'pages', which means that DPL produces a list of pages. And this is exactly what the name DPL promises.

If you set the goal parameter to 'categories' the list of pages will still be produced but you won't see it. Instead it will be used to calculate a unique ordered list of all categories these pages belong to.

This allows you to ask a question like: Given all pages that are member of category X with a title matching "y%" and which use template "Z": to which categories do these pages belong?

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?"

The output of "goal=categories" is technically a list of pages of type category. This means that you can use all DPL formatting options (mode=userformat, listseparators, columns etc.) and pseudo variables (%TITLE%, %PAGE%) to customise the layout of your report.

Technical Note:

Due to some limitations in MySQL it is currently not possible to restrict the intermediate result set of pages to a certain maximum (using the LIMIT clause). In addition the generated SQL code is not in all cases optimal (as its structure provides for complex selection criteria and therefore is unnecessarily complex in simple cases). So be careful and apply precise selection criteria.

allowcachedresults
Syntax:

Explanation:

Default: true All queries are cached by default to reduce server load as generally articles do not change often enough to require updating every page load. If immediate updates are required every page load then set this parameter to false. The cache period is handled by the parameter.

This parameter has no effect on Fandom projects since cached results is always set to true to reduce server load. The default cacheperiod is quite short though: One hour instead of 14 days for a page without DPL. In the vast majority or cases this default can be increased by one or even two orders of magnitude.

reset
Syntax:

, where keyword is one of:
 * categories
 * templates
 * images
 * links
 * all &mdash; a synonym for all of the above

The output of a DPL statement typically creates links to all pages which are part of the result set. The inclusion of contents from other pages via DPL (using 'include') normally has the consequence
 * that the page containing the DPL query becomes part of the categories of the transcluded page
 * that it shares ('adopts') their use of templates
 * that it shares their references to images
 * that it shares their references to other articles.

In some cases this may be useful. But in many cases this is not wanted. Especially when you use DPL to create a printable document which contains the full text of other articles you will probably not want to duplicate all links, template uses etc. of those articles.

The  parameter will suppress all or some of the effects described above.

There are some subtle differences here depending on the mode in which you use DPL. These differences affect the question how links, and categories etc. are treated which are direct part of the document containing the DPL query. Example: linking to Q Link and showing and using ... DPL query which includes contents from other articles. assuming that this contents contains links and images, that it uses templates and thatthe articles are part of one or more categories RESET statement at the end of the DPL query with one or more of 'categories,templates,images,links' ...

In parser extension mode (DPL tag like &lt;DPL&gt;):
 * reset=categories: will ignore categories of included contents but keep 'own' categories like 'Q Cat'.
 * reset=images: will throw away references to images contained in included contents but keep 'own' images like 'Q Image'.
 * reset=templates: will ignore templates used in included contents but keep 'own' template usage ('Q Template').
 * reset=links: will throw away all references to other pages, i.e. links contained in included contents and links like 'Q Link' will be ignored. This means that all links can be used in the normal "FORWARD" way, but no "BACKLINKS" are available for them.

If you want to avoid the above described effect of  on your 'own' links you can use. But you should know that eliminate is rather expensive in terms of computer power as it does a second parse for all included contents.

In parser function mode ( ):


 * reset=categories: will ignore all categories
 * reset=images: will throw away all references to images
 * reset=templates: will ignore all template invocations
 * reset=links: will throw away all references to other pages

As you see, using  in parser function mode will clear everything regardless whether it comes from included contents or whether it is direct part of the document containing the DPL query.

If you want to avoid the above described effect of, you can use. But you should know that eliminate is rather expensive in terms of computing power as it does a second parse for all included contents. The extra parser step is conducted as soon as you specify. In terms of extra processing needed it does not make a difference whether you specify one or more arguments for the 'eliminate' command.

If you have more than one DPL query in a document the effects will depend on the exact mode (parser extension or parser function mode), on the sequence of the statements and on the presence of 'reset' or 'eliminate' statements in each of the queries and on their individual arguments. As this is a very rare case we only give a simple rule of thumb here: Once you have used 'reset' in parser function mode or 'reset=links' in parser extension mode the effect of these statements will dominate the rest.

fixcategory
Syntax:

Use multiple commands to assign the article to more than one category.

If you use  or   the article containing your DPL statement will not be recorded in the  mediawiki link database. This may be quite useful if your article transcludes content from other pages. Without the  command your article would appear in a category if you included a text portion containing an assignment to that category.

As a side effect of using  your article will not appear in a category even if you literally assign it to one. The  allows you to make a category assignment which is not blocked by the  command.

eliminate
Syntax:

Where  is one of:


 * &mdash; a synonym for all of the above
 * &mdash; a synonym for all of the above
 * &mdash; a synonym for all of the above
 * &mdash; a synonym for all of the above
 * &mdash; a synonym for all of the above

The output of a DPL statement typically creates links to all pages which are part of the result set. The inclusion of contents from other pages via DPL (using ) normally has these consequences:
 * the page containing the DPL query becomes part of the categories of the transcluded page
 * shares ('adopts') their use of templates
 * shares their references to images
 * shares their references to other articles

In some cases this may be useful. But in many cases this is not wanted. Especially when you use DPL to create a printable document which contains the full text of other articles you will probably not want to duplicate all links, template uses etc. of those articles.

The  parameter will suppress all or some of the effects described above.

For further explanation see.

Please note that the use of  needs a considerable amount of extra computing power as it performs a second parser step for each included document.

debug
Syntax:

, where n is one of:
 * 0 &mdash; Silent mode, shows nothing
 * 1 &mdash; Quiet mode, shows (fatal) errors
 * 2 &mdash; Default mode, like 1 + shows warnings; &mdash; (default)
 * 3 &mdash; Verbose mode, like 2
 * 4 &mdash; Dump raw SQL Query; only if $wgDebugDumpSql is set to true.
 * 5 &mdash; Show wiki text output from DPL instead of parsed wiki text.

If you use debug param but not in first position in the DPL element, the new debug settings are not applied before all previous parameters have been parsed and checked. This will generate a warning for  and above.

Example:

This list will output the error for the first namespace: Media is not a valid namespace value (pseudo-namespace). Assuming you haven't changed the default debug value (2), you will also get a warning:  is not input first (before  ). So it did not apply to  but only to what's after. Indeed, you won't get the warning for the second namespace (Special) since  changed debug settings to silent mode.

DPL debug messages are translatable in. See also.

'debug=1' will suppress warning messages (e.g. if the result set of a DPL query is empty). As an alternative, you can use the statement.

execandexit
Syntax:

or

If no wiki text is given the command will be ignored. Otherwise DPL will output the wiki text and exit immediately. Note that the wiki text may be a parser function call which evaluates to an empty string.

The special word geturlargs can be used as a wiki text to transform URL arguments starting with  into variables which can then be accessed via #var (if the Variables extension is installed) or via #dplvar. Purpose:

Using this command you can prevent DPL from executing a database query; this may be useful if a necessary parameter was not given by the user. Note that an #if function call would NOT help in that case because #if evaluates its complete content before taking the "if" or the "else" path. So, emebdding a DPL call within a #if is much less efficient than using the execandexit function.

A typical use would look like this (note the double pipe symbols within the #if. Calling the following page with &DPL_cat=Country would list countries, omitting the &cat parameter would trigger the error text message (without DPL going to the database):

See also: Template:Extension DPL scroll and

Note  acts like a short-circuit evaluation. This means, for example, that successive statements to influence caching behaviour (like ) will not be interpreted.

cacheperiod
Syntax:

The default is 3600 seconds which is one hour. By comparison, the default expiration period when DPL is not involved is 1,209,600 seconds on Fandom, or 14 days. The DPL cache gets invalidated (and the page rebuilt before cacheperiod ends) when the page that hosts the DPL query is edited or whenever a page already in the results is. On the other hand, if a page that is not part of the results gets edited and starts matching the DPL query, it will not be picked up until cacheperiod ends or something else invalidates the DPL cache.

So it is perfectly fine to set the cache to 14 days for DPL queries that aren't expected to grow their number of results quickly. In most other cases, a cache of 1 day (86,400 seconds) is probably good enough.

DPL is a resource-intensive tool. Longer cache periods reduce computing costs and greenhouse gas emissions. With that said, only the first person(s) to load a page containing a DPL query whose cache has expired or is invalidated will have to wait for Fandom servers to rebuild it.