View source for Other parameters

{{DPL manual|section=Parameters|subsection=Other parameters}}
{{tocright}}


==debug==
{{DPL parameter
 |name   = debug
 |purpose= Sets debugging level.
}}


'''Syntax:'''

<code>debug=<i>n</i></code>, where {{tt|n}} is one of:
* <code>''0''</code> – Silent mode, shows nothing.
* <code>''1''</code> – Quiet mode, shows (fatal) errors.
* <code>''2''</code> – Default mode, like 1 + shows warnings; – '''(default)'''.
* <code>''3''</code> – Verbose mode, like 2.
* <code>''4''</code> – Dump raw SQL Query; only if ''$wgDebugDumpSql'' is set to true.
* <code>''5''</code> – Show wiki text output from DPL4 instead of parsed wiki text.


{{note|'''Note:''' If the debug parameter is '''not''' used in the first position of the DPL4 statement, the new debug settings are not applied before all previous parameters have been parsed and checked.''' This generates a warning for <code>debug{{=}}2</code> and above.}}


'''Example:'''<br><br><!-- transclude example from subpage-->{{#lsth:Examples/Parameter: debug (example 1)|Example}}
{{ViewTest|Examples|Parameter: debug (example 1)}}

'''Result:'''<br><br><!-- transclude example from subpage-->{{#lsth:Examples/Parameter: debug (example 1)|Result}}


'''Notes:'''
* DPL4 debug messages are translatable in ''DynamicPageList2.i18n.php''.
* <code>debug=''1''</code> suppresses warning messages (e.g., if the result set of a DPL4 query is empty).


==allowcachedresults==
{{DPL Parameter
 |name   = allowcachedresults
 |purpose= Cache query results to improve performance, keep servers from crashing under high load.
}}


'''Syntax:'''

<code>allowcachedresults=''value''</code> where {{tt|value}} is one of:
* <code>''true''</code> – ('''default''', need not be set).
* <code>''false''</code> – prevent caching.


'''Notes:'''
* 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, such as for displaying {{DPL|scroll}} navigation via {{DPL|URL parameters}}, then set this parameter to false. 
* Cache period is handled by the <code>{{DPL|cacheperiod}}</code> parameter.


==cacheperiod==
{{DPL Parameter
 |name   = cacheperiod
 |purpose= Defines the expiration period for the DPL4 cache.
}}


'''Syntax:'''

<code>cacheperiod=''number of seconds''</code> – ('''default''' is 3600, meaning 1 hour).


==goal==
{{DPL Parameter
 |name   = goal
 |purpose= Set the goal for DPL4 to either show '''pages''' (default) or '''categories''' these pages belong to.
}}


'''Syntax:'''

<code>goal=''goaltype''</code> where {{tt|goaltype}} can be one of:
* <code>''pages''</code> – ('''default''', need not be set).
* <code>''categories''</code>.


DPL4 produces a list of pages by default, and this is precisely what the name DPL4 promises.


If the goal parameter is set to 'categories' the list of pages is still be produced, but is not seen. Instead, it is used to '''calculate a unique ordered list of all categories these pages belong to'''.


This allows the asking of question like: Given all pages that are a 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 a question like: "To which categories do the pages belong which contain a reference to the current page?"


The output of <code>goal=categories</code> is technically a ''list of pages of type category''. This means that all DPL4 formatting options can be used (<code>mode=userformat</code>, <code>listseparators</code>, <code>columns</code> etc.) and pseudo variables (<code>%TITLE%</code>, <code>%PAGE%</code>) to customize the layout of the 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.


==eliminate==
{{DPL Parameter
 |name   = eliminate
 |purpose= Suppress references to pages, templates, images, categories in DPL4 output
}}


'''Syntax:'''

<code>eliminate=''keyword,..''</code> where {{tt|keyword}} is one of:
* <code>''categories''</code>
* <code>''templates''</code>
* <code>''images''</code>
* <code>''links''</code>
* <code>''all''</code> – A synonym for all of the above.


The output of a DPL4 statement typically creates links to all pages which are part of the result set. The inclusion of contents from other pages via DPL4 (using <code>{{DPL|include}}</code>) normally has these consequences:
* The page containing the DPL4 query becomes part of the categories of the transcluded page.
* It shares ('adopts') their use of templates.
* It shares their references to images.
* It shares their references to other articles.


In some cases, this may be useful. But in many cases, this is not wanted. Especially when DPL4 is used to create a printable document which contains the full text of other articles, duplicating all links, template uses etc., of those articles is probably undesired.

The <code>eliminate</code> parameter suppresses all or some of the effects described above.

For further explanation, see <code>{{DPL|reset}}</code>.

'''Note:''' The use of <code>eliminate</code> needs a considerable amount of extra computing power as it performs a second parser step for each included document.


==reset==
{{DPL Parameter
 |name   = reset
 |purpose= Suppress references to pages, templates, images, categories in DPL4 output
}}


'''Syntax:'''

<code>reset=''keyword,..''</code>, where {{tt|keyword}} is one of:
* <code>''categories''</code>
* <code>''templates''</code>
* <code>''images''</code>
* <code>''links''</code>
* <code>''all''</code> – A synonym for all of the above.


The output of a DPL4 statement typically creates links to all pages which are part of the result set. The inclusion of contents from other pages via DPL4 (using <code>include</code>) normally has the consequences:
* The page containing the DPL4 query becomes part of the categories of the transcluded page.
* It shares ('adopts') their use of templates
* It shares their references to images
* It shares their references to other articles.


In some cases, this may be useful. But in many cases, this is not wanted. Especially when DPL4 is used to create a printable document which contains the full text of other articles, duplicating all links, template uses etc., of those articles is probably undesired.

The <code>reset</code> parameter suppresses all or some of the effects described above.

There are some subtle differences here depending on the mode in which DPL4 is used. These differences affect the question of how links, and categories etc., are treated which are direct part of the document containing the DPL4 query.
Example:
<pre><nowiki>
[[Category:Q Cat]] linking to [[Q Link]] and showing [[Image:Q Image]] and using {{Q Template}}
... DPL4 query which includes contents from other articles.
    assuming that this contents contains links and images, 
             that it uses templates and that the articles are part of one or more categories
    RESET statement at the end of the DPL4 query with one or more of 'categories,templates,images,links'
...
</nowiki></pre>


'''In parser extension mode''' (tag like <code><nowiki><dpl></nowiki></code>):
* <code>reset=''categories''</code> – Ignores categories of included contents but keeps 'own' categories like 'Q Cat'.
* <code>reset=''images''</code> – Throws away references to images contained in included contents but keeps 'own' images like 'Q Image'.
* <code>reset=''templates''</code> – Ignores templates used in included contents but keeps 'own' template usage ('Q Template').
* <code>reset=''links''</code> – Throws away all references to other pages, i.e., links contained in included contents and links like 'Q Link' are ignored. This means all links can be used in the normal "FORWARD" way, but no "BACKLINKS" are available for them.


To avoid the above described effect of <code>reset</code> on one's 'own' links, <code>{{DPL|eliminate}}</code> can be used. However, it is important to note that ''eliminate'' is rather expensive in terms of computer power, as it does a second parse for all included contents.


''' In parser function mode''' (<code><nowiki>{{#dpl:....}}</nowiki></code>):
* <code>reset=''categories''</code> – Ignores all categories.<br>
* <code>reset=''images''</code> – Throws away all references to images.
* <code>reset=''templates''</code> – Ignores all template invocations.
* <code>reset=''links''</code> – Throws away all references to other pages.


Using <code>reset</code> in parser function mode clears everything, regardless of whether it comes from included contents or whether it is direct part of the document containing the DPL4 query.

To avoid the above described effect of <code>reset</code>, <code>{{DPL|eliminate}}</code> can be used. However, ''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 ''eliminate'' is specified. In terms of extra processing needed, it does not make a difference whether one or more arguments are specified for the ''eliminate'' command.

If there is '''more than one DPL4 query''' in a page, the effects 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, only a simple rule of thumb is given here: Once 'reset' is used in parser function mode or <code>reset=links</code> in parser extension mode, the effect of these statements dominates the rest.


==fixcategory==
{{DPL Parameter
 |name   = fixcategory
 |purpose= Assign the article containing a DPL4 statement to a category, although <code>reset</code> was used.
}}


'''Syntax:'''

<code>fixcategory=''category name''</code>


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

If <code>reset=''all''</code> or <code>reset=''categories''</code> are used, the article containing the DPL4 statement is not be recorded in the MediaWiki link database. This may be quite useful if an article transcludes content from other pages. Without the <code>{{DPL|reset}}</code> command, the article would appear in a category if a text portion containing an assignment to that category was used.

As a side effect of using <code>reset=''all''</code>, the article does not appear in a category, even if one is literally assigned to it.
<code>fixcategory</code> allows a category assignment to be made which is not blocked by the <code>reset</code> command.


==execandexit==
{{DPL Parameter
 |name   = execandexit
 |purpose= Process the command given as an argument and then exit immediately.
}}


'''Syntax:'''

<code>execandexit=''wiki text''</code>
<br>or<br>
<code>execandexit=''geturlargs''</code>


If no wiki text is given, the command is ignored. Otherwise, DPL4 outputs the wiki text and exits immediately.
Note that the wiki text may be a parser function call which evaluates to an empty string.

'''Example:'''<br><br><!-- transclude example from subpage-->{{#lsth:Examples/Parameter: execandexit (example 1)|Example}}
{{ViewTest|Examples|Parameter: execandexit (example 1)}}

'''Result:'''<br><br><!-- transclude example from subpage-->{{#lsth:Examples/Parameter: execandexit (example 1)|Result}}

The special word ''geturlargs'' can be used as a wiki text to transform URL arguments starting with <code>DPL_</code> into variables, which can then be accessed via #var (if the [[mw:Extension:Variables|Variables]] extension is installed) or via #dplvar.

Using this command, DPL4 can be prevented from executing a database query; this may be useful if the user did not give a necessary parameter. Note that an <code><nowiki>{{#if:}}</nowiki></code> ([[mw:Help:Extension:ParserFunctions|Parser Functions]] extension) function call would NOT help in that case because <code>#if</code> evaluates its complete content before taking the "if" or the "else" path. So, embedding a DPL4 call within an <code>#if</code> is much less efficient than using the ''execandexit'' function.


'''Example:'''<br><br><!-- transclude example from subpage-->{{#lsth:Examples/Parameter: execandexit (example 2)|Example}}
{{ViewTest|Examples|Parameter: execandexit (example 2)}}


'''Result:'''<!-- transclude example from subpage-->{{#lsth:Examples/Parameter: execandexit (example 2)|Result}}


'''See also:''' [[Template:DPL4 scroll]] and {{DPL|scrolling}}.


{{note|'''Note:''' <code>execandexit</code> acts like a short-circuit evaluation. This means, for example, that successive statements to influence caching behavior (like <code>{{DPL|allowcachedresults}}</code>) are not interpreted.}}

[[Category:Primary Module|05]]