Help:ParserFunctions

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The MediaWiki extension ParserFunctions is a collection of parser functions (note the difference between the name of the collection, and the general term). These parser functions have a hash character in front of the function name, so they typically have the syntax:

Please note that ParserFunctions are unavailable in some MediaWiki installations, check out Special:Version below Parser hooks, individual functions such as expr and switch are listed below Parser function hooks.

Functions
The extension defines nine functions: expr, if, ifeq, ifexist, ifexpr, switch, time, rel2abs, and titleparts</tt>.

<h3 style="background: beige">#expr:
 * syntax:

The expr</tt> function computes mathematical expressions based on permutations of numbers (or variables/parameters that translate to numbers) and operators. It does not recognize strings (use ifeq</tt> below instead). The accuracy and format of numeric results varies with the server's operating system.

Operators are listed below. In a complex expression, operators are evaluated from left to right with the following precedence (explained in more detail in Help:Calculation):
 * 1) grouping (parentheses);
 * 2) unary (+/- signs and NOT);
 * 3) multiplicative (*, /, div, mod);
 * 4) additive (+ and -);
 * 5) round;
 * 6) comparative (=, !=, &lt;, &gt;, etc.);
 * 7) logical AND;
 * 8) logical OR.

When evaluating as boolean, "0" is considered false and any other non-space value is true (boolean true is represented as "").

Decimal numbers use "." as a decimal point ( can be used to change the decimal point to a comma for the appropriate locales). Scientific notation with E</tt> plus exponent is not yet supported on input for expressions, but used on output (see Help:Calculation).

<h3 style="background: beige">#if:
 * syntax:
 * {{ft|#if| |  function is an if-then-else construct. The condition is always true unless it is empty or whitespace-only. The code in the second argument is parsed if the condition is true, and the third argument is parsed if the condition is false (either or both may be blank, and the code-if-false argument can be omitted entirely).

The condition is evaluated as text, so mathematical expressions will always evaluate as true; to use expressions as conditions, see #ifexpr</tt>. It is not possible to distinguish between an undefined parameter in a template and a blank one (it is possible with #ifexpr</tt>).

Examples:
 * {{ft|#if| foo | do if true | do if false }} = {{#if:foo| do if true | do if false}}
 * {{ft|#if| 0  | do if true | do if false }} = {{#if:0  | do if true | do if false}}
 * {{ft|#if|   | do if true | do if false }} = {{#if:   | do if true | do if false}}

<h3 style="background: beige">#ifeq:
 * syntax:
 * {{ft|#ifeq| | |  function compares two strings or numbers, and returns the second argument if they are equal and the third argument if not equal (either or both may be blank, and the code-if-not-equal argument can be omitted entirely).

Comparison of strings is case-sensitive (for example, {{#ifeq:A|a|A = a|A != a}}). If both strings can be interpreted numerically, they will be compared numerically (for example, {{#ifeq:01|1|01 = 1|01 != 1}}); To force a string-based comparison, add non-numerical characters (such as quotes ) to both compared arguments.

It is possible to distinguish between undefined and empty template parameters by comparing default values (if the parameter is defined, it will overwrite the default value even if blank):
 * {{ft|#ifeq| {{{parameter|default}}} | default | parameter not defined | parameter defined }} = {{#ifeq:{{{parameter|default}}} | default | parameter not defined | parameter defined}}

Issues:
 * Text between &lt;nowiki&gt; tags is temporarily replaced by a unique code. This affects comparisons: {{ft|#ifeq| &lt;nowiki&gt;abc&lt;/nowiki&gt; | &lt;nowiki&gt;abc&lt;/nowiki&gt; | equal | not equal }} returns "{{#ifeq: abc | abc | equal | not equal}}".

<h3 style="background: beige">#ifexist:

{{ft|#ifexist}} returns one of two results based on whether or not a particular page exists.

{{ft|#ifexist| &lt;page name&gt; | &lt;wikitext if page exists&gt; | &lt;wikitext if page does not exist&gt; }}

The usual case-sensitivity applies: if a page exists then also a non-canonical name for that page gives a positive result. E.g. on Meta:
 * {{ft|#ifexist| Bugs|Foo|RFC 3092 }} gives {{#ifexist:Bugs|Foo|RFC 3092}}, because Bugs exists
 * {{ft|#ifexist| bugs|Foo|RFC 3092 }} gives {{#ifexist:bugs|Foo|RFC 3092}}, because bugs is in canonical form the existing Bugs
 * {{ft|#ifexist| BUGS|Foo|RFC 3092 }} gives {{#ifexist:BUGS|Foo|RFC 3092}} because BUGS does not exist
 * {{ft|#ifexist| m:Help:Calculation|Yes|Oops }} gives {{#ifexist:m:Help:Calculation|Yes|Oops}} although m:Help:Calculation exists, because of the interwiki prefix.

The first parameter is the title to check for, the second is the positive result, and the third, the negative result. If the parameter passed does not produce a valid title object, then the result is negative.

{{tim|exists}} gives the same result, except that the result is positive for an interwiki link. You can also handle an interwiki link differently with {{tim|if interwiki link}}.

{{ft|#ifexist}} doesn't handle relative paths (like '../foo'), for that, use it in combination of {{ft|#rel2abs}}.

The page where {{#ifexist:foo}} appears is listed on Special:Whatlinkshere/foo (as a page which links to foo), see below.

On Wikimedia wikis there is a maximum for the number of distinct pages for which #ifexist is called on a page. A call of #ifexist after a transclusion of the same page does not require an extra database query and is therefore not counted. A call beyond the maximum returns "false". The html-source of each page shows the counted number of calls, as well as the maximum. The maximum is currently 500, and it has been announced that this will be lowered to 100. .

{{ft|#ifexist}} always returns the false condition with Special pages:
 * {{ft|#ifexist| Special:Version|works|doesn't work }} gives {{#ifexist:Special:Version|works|doesn't work}}

<h3 style="background: beige">#ifexpr: {{ft|#ifexpr}} evaluates a mathematical expression (see #expr) and returns one of two strings depending on the result.

{{ft|#ifexpr| &lt;expression&gt; | &lt;then text&gt; | &lt;else text&gt; }}

If the expression evaluates to zero, then the else text is returned, otherwise the then text is returned. Expression syntax is the same as for expr</tt>.

Example:
 * {{ft|#ifexpr| 10 > 9 | yes | no }} {{#ifexpr: 10 > 9|yes|no}} -- Because 10 is greater than 9.


 * At the moment the else text is also returned for an empty expression&#58;
 * {{ft|#ifexpr| {{ns:0}}|Toast| or else }} gives {{#ifexpr: {{ns:0}}|Toast|or else}}


 * Omitting both then text and else text gives no output except possibly an error message; this can be used to check the correctness of an expression, or to check the wording of the error message (emulated assertions, forced errors)&#58;
 * {{ft|#ifexpr|1/{{ft sub|#ifeq|{{ft sub|ns|4}} | Meta | 1 | 0 }}}} {{#ifexpr: 1/{{#ifeq: {{ns:4}}|Meta|1|0}}}} -- no result, hence " 1/{{#ifeq: {{ns:4}}|Meta|1|0}}" is a correct expression
 * {{ft|#ifexpr|1/{{ft sub|#ifeq|{{ft sub|ns|0}} | Meta | 1 | 0 }}}} {{#ifexpr: 1/{{#ifeq: {{ns:0}}|Meta|1|0}}}}
 * {{ft|#if|{{ft sub|#ifexpr| 1=2 }} | wrong | correct }} {{#if:{{#ifexpr: 1=2}}|wrong|correct}} -- "1=2" is a correct Boolean expression (not to be confused with one with the value 1, representing "true")
 * {{ft|#if|{{ft sub|#ifexpr|1E2}} | wrong | correct }} {{#if:{{#ifexpr: 1E2}}|wrong|correct}} -- "1E2" not allowed in expressions
 * {{ft|#if|{{ft sub|#ifexpr|1/0}} | wrong | correct }} {{#if:{{#ifexpr: 1/0}}|wrong|correct}} -- "1/0" not allowed


 * {{ft|#if|{{ft sub|#ifexpr| a=b }} | wrong | correct }} {{#if:{{#ifexpr: a=b}}|wrong|correct}} ("a=b" not allowed, to compare strings use #ifeq)

Example of an application: {{ #if: {{#ifexpr: {{PAGENAME}} }} || action if PAGENAME is a number (or correct numeric expression) }}

For another application, see also {{tim|evalns}}.

<h3 style="background: beige">#switch:

compares a single value against multiple others, returning a string if a match is found. The syntax is basically:

{{ft begin|#switch}} &lt;comparison value&gt; | &lt;value{{sub|1}}&gt; = &lt;result{{sub|1}}&gt; | &lt;value{{sub|2}}&gt; = &lt;result{{sub|2}}&gt; | ... | &lt;value{{sub|n}}&gt; = &lt;result{{sub|n}}&gt; | &lt;default result&gt; {{ft_end}}

will search through each value passed until a match is found with the comparison value. When found, the result for that value is returned (the text string after the equal sign). If no match is found, but the last item has no equal sign in it, it will be returned as the default result. If your default result must have an equal sign, you may use :

{{ft begin|#switch}} &lt;comparison value&gt; | &lt;value&gt; = &lt;result&gt; | #default = &lt;default result&gt; {{ft end}}

Note that it's also possible to have "fall through" for values (reducing the need to duplicate results). For example:

{{ft begin|#switch}} &lt;comparison value&gt; | &lt;value{{sub|1}}&gt; | &lt;value{{sub|2}}&gt; | &lt;value{{sub|3}}&gt; = &lt;result{{sub|1, 2, 3}}&gt; | ... | &lt;value{{sub|n}}&gt; = &lt;result{{sub|n}}&gt; | &lt;default result&gt; {{ft end}}

Note how value{{sub|1}} and value{{sub|2}} contain no equal sign. If they're matched, they are given the result for value{{sub|3}} (that is, whatever is in result{{sub|3}}).


 * As for #ifeq: the comparison is numerical where possible&#58;
 * {{ft|#switch| +07 | 7 = Yes | 007 = Bond | No }} gives {{ #switch: +07 | 7 = Yes | 007 = Bond | No }}
 * {{ft|#switch| "+07"|"7"= Yes |"007"= Bond | No }} gives {{ #switch:"+07"|"7"= Yes |"007"= Bond | No }}


 * The matched value can be empty, therefore the following constructs are equivalent&#58;
 * {{ft|#if| {&#123;ns:0&#125;} | not empty | empty }} gives {{ #if: {{ns:0}} | not empty | empty }}
 * {{ft|#switch| {&#123;ns:0&#125;}|=empty|not empty }} gives {{ #switch:{{ns:0}}|=empty|not empty }}

Comparison of strings is case-sensitive:
 * {{ft|#switch| A | a=lower | A=UPPER }} gives {{#switch: A | a=lower | A=UPPER }}
 * {{ft|#switch| A | a=lower | UPPER }} gives {{#switch: A | a=lower | UPPER }}
 * {{ft|#switch| a | a=lower | UPPER }} gives {{#switch: a | a=lower | UPPER }}

This is not to be confused with the fact that parser function names are case-insensitive:
 * {{ft|#swItch| A | a=lower | UPPER }} gives {{#swItch: A | a=lower | UPPER }}

To have the #switch statement be case-insensitive, use the construct {{lc:}} or {{uc:}}
 * {{ft|#switch| {{lc:A}} | a=lower | A=UPPER }} gives {{#switch: {{lc:A}} | a=lower | A=UPPER }}
 * {{ft|#switch| {{lc:A}} | a=lower | UPPER }} gives {{#switch: {{lc:A}} | a=lower | UPPER }}
 * {{ft|#switch| {{lc:a}} | a=lower | UPPER }} gives {{#switch: {{lc:a}} | a=lower | UPPER }}

This is usually used in templates, when you want to have case-insensitivity on in param values: {{ft begin|#switch}} {{ft sub|lc| {{{1| B }}} }} | a | b | c = abc or ABC | A | B | C = Memory corruption due to cosmic rays | #default = N/A {{ft end}} gives {{#switch: {{lc: {{{1| B }}} }} }}
 * a
 * b
 * c = abc or ABC
 * A
 * B
 * C = Memory corruption due to cosmic rays
 * #default = N/A

#switch may be used instead of #ifeq:
 * {{ft|#switch| a | a=true | false }} gives {{#switch: a | a=true | false }}
 * {{ft|#ifeq| a | a | true | false }} gives {{#ifeq: a | a | true | false }}

<h3 style="background: beige">#time:

{{ft|#time}} is a time and date formatting function (for dates from 1 Jan 1970 only!). The syntax is:

{{ft|#time|format}} {{ft|#time|format &#124; time}}

If the time is not specified, the time at which the article is converted to HTML is used. Note that due to caching, this may be up to a week different to the time at which the article is viewed. Manual updates may be required, this can be achieved by saving the page without making any changes (a "null edit") or viewed with  in search string of URL or viewed by a user whose option is "Disable page caching".

The format parameter is a format string similar to the one used by PHP's date.

The following format codes have the same meaning as in PHP. Significant differences from PHP's behaviour, apart from internationalisation (i.e. language and locale differences), should be considered an error of ParserFunctions and should be reported. All numeric format codes return numbers formatted according to the local language, use the xn code described below to override this.

The following format codes are extensions to the PHP syntax:

Any unrecognised character will be passed through to the output unmodified. There are also two quoting conventions which can be used to output literal characters.


 * Characters enclosed in double quotes will be considered literal (with the quotes themselves removed). Unmatched quotes will be considered literal quotes. Example:
 * {{ft|#time|"The month is" F}} &rarr; {{ #time: "The month is" F }}
 * {{ft|#time|i's"}} &rarr; {{ #time: i's" }}
 * Backslash escaping as in PHP's date is supported. \H produces a literal H, \" produces a literal ".

More format codes may be added in the future, as demanded by the users of this extension. This may come in the form of either a more complete implementation of PHP's format codes, or additional "x" codes.

The format of the time parameter is identical to the one used by PHP's function strtotime. It supports both absolute and relative dates, such as "December 11</tt>" and/or "+10 hours</tt>", which can be used for timezone translation. See also the GNU tar manual for more information.

Examples

 * gives ""
 * gives ""
 * gives ""
 * gives "" (32 days ago)
 * gives "" (6 hours later than UTC)
 * gives ""
 * gives "" (17 months ago)

In combination with user-specified date formatting:
 * gives ""
 * gives ""

Both give the user-specified format; the two are different if no preference has been specified.

Range
The range of proper functioning is 01 January 1970 00:00:01 through 19 January 2038 03:14:07, or 1 through $$2^{31}-1$$ seconds after the start of 1970 (the Year 2038 problem). For arbitrary dates that may exceed this range, use date computing templates such as instead.

Dates before 1901 give an error message, dates between 1901 and 1970 even give (perhaps depending on the server) a wrong result (!):


 * 5 April 1967
 * 5 April 1867

Incomplete dates

 * (not a year but a time: today, 20:07)
 * (19:97 is not a valid time, therefore interpreted as year, giving the current date and time in that year)
 * (19:67 is not a valid time, therefore interpreted as year; this gives a date that is out of range which is changed to the start of the valid range)
 * (start of the month)
 * (specified date of the current year)

February 29
Caution should be taken with February 29, as will vary with the year. For example


 * gives
 * gives

Timezones
Give UTC for a specified time, expressed in time zone UTC-3:

Give the UTC 3 hours ago:

Give the UTC 3 hours before a specified time expressed as UTC:

Give the UTC 3 hours before a specified time expressed in time zone UTC-3:

Thus "-0300" and "-3" add 3 hours, while "-3 hours" subtracts them.

<h3 style="background: beige">#rel2abs:

converts a relative path to an absolute path.

A relative path is a path starting with '/', './', '../'. or is containing '/../' or '/.' or is simply the strings '..' or '.'.

If a base path</tt> is given, is should be defined in an absolute syntax.

Example:
 * If standing in Help:Foo/bar</tt> and is calling, the result will be </tt>
 * If standing in Help:Foo</tt> and is calling, the result will be </tt>
 * If standing in Help:Foo</tt> and is calling, the result will be </tt>
 * If calling, the result will be <tt></tt>
 * If calling, the result will be <tt></tt>

There is no checks if the path do exist, for that you might use in combination:
 * gives <tt></tt>
 * gives <tt></tt>

<h3 style="background: beige">#titleparts:

 

returns n_of_segments slash-separated segments of pagename, starting from the specified starting segment.
 * if starting_from is omitted, it is considered to be equal 1
 * namespace part of pagename is converted into localized namespace name

Examples with one numeric parameter:

Examples with two numeric parameters:
 * This gives two parts of the title, starting at the second part. Likewise:
 * This gives two parts of the title, starting at the second part. Likewise:



Examples with negative parameters (which means "counting from the right"):

Introduced in r22711, fixed to allow negative parameters in r28708. See also bug 6067.

<h3 style="background: beige">#iferror:

returns error if the expression contains a as generated by #expr, #ifexpr, #time, #rel2abs, and some other MediaWiki situations (such as recursive depth and template loop checks). This is most useful in catching bad input passed to such parserfunctions. For example:


 * gives
 * gives

The last two parameters are also optional. If the success parameter is omitted, then the expression is returned on success. If the error parameter is also omitted, then no output is generated on error, and expression is returned on success.
 * gives
 * gives
 * gives
 * gives

Thus:
 * means "render wikitext if it is correct, and otherwise alternative".
 * means "render wikitext if it is correct".


 * Note: this functionality replaces a bug in the older preprocessor allowing #switch to catch expression errors.

See also: r29774, r29775, r29877.

Caveats
Like other parser functions the parser functions in this extension are affected by 5678 in a predictable way. Summary: undefined parameters can be overwritten by corresponding parameters, for details see 5678 and Substitution. Substitution is the only case where this is critical with respect to parameter defaults. It doesn't affect defined parameters.

Substitution
Applying "subst:" to a parser function works, provided that there is no space between "subst:" and "#". For details see Help:Substitution. Note that unless a technique like optional substitution is used, substituting a template which uses a parser function does not replace that parser function with its result. This is often undesirable.

See also the previous section.

Tables
Currently wiki pipe table syntax doesn't work inside conditionals, but there are some workarounds. Note that "<tt>|</tt>" and "<tt>=</tt>" were always tricky within templates, this is no new issue.
 * Hide the pipe from parser functions by putting it in a template, e.g..
 * Use html style table syntax instead of wiki style table syntax. NB: $wgUserHtml must be true (this has since been removed, and thus should not need to be set to 'true' - check if it is relevant for your version). This may not work without setting .
 * See also Help:Table, completely empty rows or columns are not displayed. Empty cells could be also transformed into dummy <tt>&amp;nbsp;</tt> cells on pages not affected by 5569.

If all else fails, try setting in your.

useTidy
If you decide to use this, you will need to download the HTML tidy programme from http://tidy.sourceforge.net/.

Expressions

 * div is not integer division and is redundant, use / (slash) for real divisions.
 * mod uses PHP's % operator, which is different from modulo-operators in all other programming languages, see also and 6068.
 * mod sometimes returns wrong results for the same input values, see 6356 and /MOD10000. Update: values less than 1E+12 are apparently not affected.
 * Valid #expr: results like are not yet supported as #expr: input:
 * yields .
 * Under certain conditions round 0 results in -0 instead of 0. For an expression x using 0+(x) fixes this oddity.

Newlines and spaces
Newlines and spaces are stripped from the start and end of parameters of all parser functions. In cases where these matter, e.g. in wikitable syntax, for conditionals use as a workaround.

See also Help:Newlines and spaces.

Code execution
Oddly, the page to which #ifexist is applied (i.e. the page whose existence is the condition) is registered as link target of a link from the page with #ifexist. (See bug #12019.)

See also.

Installation
Download all 4 of these files and put them in a new directory called ParserFunctions in your extensions directory.


 * Expr.php
 * ParserFunctions.php
 * ParserFunctions.i18n.php
 * ParserFunctions.i18n.magic.php

If you don't have php5 use these files instead (older revision):
 * Expr.php
 * ParserFunctions.php

Then put the following at the end of your LocalSettings.php:

require_once( "$IP/extensions/ParserFunctions/ParserFunctions.php" );

If you get errors such as "Warning: require_once(/extensions/ParserFunctions/ParserFunctions.php) [function.require-once]: failed to open stream:", you should substitute the line for:

require_once( 'extensions/ParserFunctions/ParserFunctions.php' );

You can also browse the code tree here:


 * ParserFunctions in MediaWiki SVN

Troubleshooting

 * ''The Current version of ParserFunctions requires php5 to function.

INSTALLATION WARNING: MediaWiki: 1.9.1, PHP: 5.1.2-Debian-0.1~sarge1 (apache2handler) function ctype_alpha not available, had to add the following to Expr.php if ( !function_exists('ctype_alpha') ) { function ctype_alpha($string) { //if ( !preg_match('|[^\pL]|', $string) ) /* Warning: preg_match [function.preg-match]: Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset 3 in        /.../extensions/ParserFunctions/Expr.php on line 6 */       /* alternative: */ // if ( !preg_match('|[^A-Za-z]|', $string) ) return true; else return false; } }

If you are using Gentoo Linux's portage system to install php, be sure to have the "ctype" USE flag set for dev-lang/php to avoid the above error.

Bugs
In version 1.6 and 1.7 if a user has the Cite.php extension already installed, an error is created when running ParserFunctions, "Unknown datatype in hooks for ParserClearState", a simple fix has been found by editing Cite.php. ]

1.11.0
I found that the files above didn't work and that I needed the latest from the svn trunk http://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions/ParserFunctions/

1.8 and up
All the ParserFunctions work under 1.8 and up, also in the localised forms.

1.7
All the ParserFunctions work under 1.7, but only in English. However, the extension may cause problems when used together with the Cite extension; cf. . For the #time parser functions to work, you must also download SprintfDateCompat.php to the extensions/ParserFunctions directory.

1.6
When including the ParserFunctions in 1.6, some notices may be shown. Removing the following line (line 10) in ParserFunctions.php fixes the problem:

$wgHooks['LanguageGetMagic'][]      = 'wfParserFunctionsLanguageGetMagic';

Or alternatively adding the default language to the header function on line 169 may solve the problem:

function wfParserFunctionsLanguageGetMagic( &$magicWords, $langCode='en' ) {

For the #time parser functions to work, you must also download SprintfDateCompat.php to the extensions/ParserFunctions directory. But actually that won't fix the problem.

If you're not planning to support #time, you may find removing this line helps avoid an error in the ParserClearState call chain:

$wgHooks['ParserClearState'][] = array( &$wgExtParserFunctions, 'clearState' );

Most ParserFunctions (except #if, which does not work at all) work just as well on MediaWiki 1.6, but the syntax of ParserFunctions is without the '#' character. If you want to use the '#' character, find this section of ParserFunctions.php: $wgParser->setFunctionHook( 'expr', array( &$wgExtParserFunctions, 'expr' ) ); $wgParser->setFunctionHook( 'if', array( &$wgExtParserFunctions, 'ifHook' ) ); $wgParser->setFunctionHook( 'ifeq', array( &$wgExtParserFunctions, 'ifeq' ) ); $wgParser->setFunctionHook( 'ifexpr', array( &$wgExtParserFunctions, 'ifexpr' ) ); $wgParser->setFunctionHook( 'switch', array( &$wgExtParserFunctions, 'switchHook' ) ); $wgParser->setFunctionHook( 'ifexist', array( &$wgExtParserFunctions, 'ifexist' ) );

Then, replace it with this:

$wgParser->setFunctionHook( '#expr', array( &$wgExtParserFunctions, 'expr' ) ); $wgParser->setFunctionHook( '#if', array( &$wgExtParserFunctions, 'ifHook' ) ); $wgParser->setFunctionHook( '#ifeq', array( &$wgExtParserFunctions, 'ifeq' ) ); $wgParser->setFunctionHook( '#ifexpr', array( &$wgExtParserFunctions, 'ifexpr' ) ); $wgParser->setFunctionHook( '#switch', array( &$wgExtParserFunctions, 'switchHook' ) ); $wgParser->setFunctionHook( '#ifexist', array( &$wgExtParserFunctions, 'ifexist' ) );

A simple fix for #if in this version -

Replace:

function ifHook( &$parser, $test = , $then = , $else = '' ) { if ($test !== '') {

on line 57 with:

function ifHook( &$parser, $test = , $then = , $else = '' ) { if ( (string)$test !== '' ){

Although the above fix doesn't appear to work on PHP 4.3.9

If you find some template responses are being unexpectedly wrapped in &lt;pre&gt;&lt;/pre&gt;

I saw this problem in 1.6.10 using the workarounds here and worked around it by making sure all results from ParserFunction callbacks were trimmed. If a result had a leading space character, then that portion of the template would be wrapped in pre tags. Couldn't figure out what part of the parser was doing this. But force trimming might be a potential workaround based on your needs.

Alteration and localization
The file ParserFunctions.i18n.php contains the localization for the parserfunctions. Adding more may be done by editing it according to the following guidelines.

In the latest MediaWiki versions, a new case for the language code should be added to function efParserFunctionsWords, for example: $words['fr'] = array(	   'expr'       => array( 0, 'calcul',        'expr' ),            'if'         => array( 0, 'si',            'if' ),            'ifeq'       => array( 0, 'si-similaire',  'ifeq' ),            'ifexpr'     => array( 0, 'si-calcul',     'ifexpr' ),            'switch'     => array( 0, 'achemine',      'switch' ),	    'default'    => array( 0, '#default' ); // same            'ifexist'    => array( 0, 'si-existe',     'ifexist' ),	    'time'       => array( 0, 'temps',         'time' ),	    'rel2abs'    => array( 0, 'rel-a-abso',    'rel2abs' ),	    'titleparts' => array( 0, 'part-titre',    'titleparts' ),        );
 * Please note that every hook established in function wfSetupParserFunctions must have an associated magic-words statement for it to work. Failure to associate a magic word may result in PHP warning messages (see bug #10166).

This method may not work on older version. Alternatively, hooks may be established in function wfSetupParserFunctions, as follows. // fr $wgParser->setFunctionHook( '#calcul', array( &$wgExtParserFunctions, 'expr' ) ); $wgParser->setFunctionHook( '#si', array( &$wgExtParserFunctions, 'ifHook' ) ); $wgParser->setFunctionHook( '#si-similaire', array( &$wgExtParserFunctions, 'ifeq' ) ); $wgParser->setFunctionHook( '#si-calcul', array( &$wgExtParserFunctions, 'ifexpr' ) ); $wgParser->setFunctionHook( '#achemine', array( &$wgExtParserFunctions, 'switchHook' ) ); $wgParser->setFunctionHook( '#si-existe', array( &$wgExtParserFunctions, 'ifexist' ) ); $wgParser->setFunctionHook( '#temps', array( &$wgExtParserFunctions, 'time' ) );
 * Tested on MediaWiki 1.6.10