Help:Extension:ParserFunctions/de

Die Erweiterung bietet elf zusätzliche Funktionen, um die "Magic words" zu ergänzen, die es in MediaWiki bereits gibt. Alle Funktionen, die diese Erweiterung unterstützt, haben folgende Form:
 *  

#expr
Diese Funktion berechnet einen mathematischen Ausdruck und gibt den errechneten Wert aus.


 *  

Die verfügbaren Operatoren sind rechts aufgelistet, in der Reihenfolge des Rangs. Siehe für nähere Details über die Funktion der einzelnen Operatoren. Genauigkeit und Format des ausgegebenen Ergebnisses hängen vom Betriebssystem des Wikiservers sowie dem Zahlenformat der eingestellten Sprache ab.

Bei Nutzung der ergibt 0 immer falsch und jeder andere Wert, ob positiv oder negativ, immer wahr:


 *   → 
 *   → 

Ein leerer eingegebener Ausdruck erzeugt eine leere Ausgabe. Ungültige Ausdrücke erzeugen verschiedene Fehlermeldungen (welche durch Nutzung der Funktion #iferror abgefangen werden können):


 *   →  
 *  </tt> → 
 *  </tt> → 

#if

 *  </tt>

Diese Funktion überprüft, ob der eingegebene Ausdruck nicht leer ist. Sie gibt falsch aus, wenn der eingegebene Ausdruck leer ist oder nur Leerzeichen und Zeilenumbrüche enthält.


 *  </tt> → 
 *  </tt> → 
 *  </tt> → 
 *  </tt> → 

Der eingegebene Ausdruck wird nur als reiner Text gewertet, mathematische Ausdrücke werden nicht berechnet.


 *  </tt> → 
 *  </tt> → 

Es können auch Parameter weggelassen werden:


 *  </tt> →  
 *  </tt> →  
 *  </tt> →  

Siehe Help:Parser functions in templates/de für weitere Beispiele zu dieser Funktion.

#ifeq
Diese Funktion vergleicht zwei Ausdrücke und ermittelt, ob sie gleich sind.


 *  </tt>

Wenn beide Ausdrücke einen gültigen Zahlenwerte ergeben, werden die Ergebnisse verglichen:


 *  </tt> → 
 *  </tt> → 
 *  </tt> → 
 * <tt> </tt> → 

Ansonsten wird der Text verglichen. Dabei wird auf Groß- und Kleinschreibung geachtet:


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 

<!--

#iferror
This function takes an input Ausdruck and returns one of two results; the function evaluates to <tt>true</tt> if the input Ausdruck contains an HTML object with <tt>class="error"</tt>, as generated by other parser functions such as <tt>#expr</tt>, <tt>#time</tt> and <tt>#rel2abs</tt>, template errors such as loops and recursions, and other "failsoft" parser errors.


 * <tt> </tt>

One or both of the return Ausdrucks can be omitted. If the <tt>correct</tt> Ausdruck is omitted, the <tt>test Ausdruck</tt> is returned if it is not erroneous. If the <tt>error</tt> Ausdruck is also omitted, an empty Ausdruck is returned on an error:


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → &zwnj;
 * <tt> </tt> → 

#ifexpr
This function evaluates a mathematical expression and returns one of two Ausdrucks depending on the boolean value of the result:


 * <tt> </tt>

The <tt>expression</tt> input is evaluated exactly as for <tt>#expr</tt> above, with the same operators being available. The output is then evaluated as a boolean expression.

An empty input expression evaluates to false:


 * <tt> </tt> → 

As mentioned above, zero evaluates to false and any nonzero value evaluates to true, so this function is equivalent to one using <tt>#ifeq</tt> and <tt>#expr</tt> only:


 * <tt> </tt>

except for an empty or wrong input expression (an error message is treated as an ordinary Ausdruck; it is not equal to zero, so we get <tt>value if true</tt>).

Either or both the return values may be omitted; no output is given when the appropriate branch is left empty:


 * <tt> </tt> → 
 * <tt> </tt> →  
 * <tt> </tt> →  
 * <tt> </tt> →  
 * <tt> </tt> →  

#ifexist
This function takes an input Ausdruck, interprets it as a page title, and returns one of two values depending on whether or not the page exists on the local wiki.


 * <tt> </tt>

The function evaluates to <tt>true</tt> if the page exists, whether it contains content, is visibly blank (contains meta-data such as category links or magic words, but no visible content), is blank, or is a redirect. Only pages that are redlinked evaluate to false, including if the page used to exist but has been deleted.


 * <tt> </tt> → 
 * <tt> </tt> → 

The function evaluates to true for system messages that have been customised, and for special pages that are defined by the software.


 * <tt> </tt> → 
 * <tt> </tt> →
 * <tt> </tt> →

<tt>#ifexist:</tt> is considered an "expensive parser function"; only a limited number of which can be included on any one page (including functions inside transcluded templates). When this limit is exceeded, the page is categorised into Category:, and any further <tt>#ifexist:</tt> functions automatically return false, whether the target page exists or not.

If a page checks a target using <tt>#ifexist:</tt>, then that page will appear in the list for the target page. So if the code <tt> </tt> were included live on this page, /Foo will list.

On wikis using a shared media repository, <tt>#ifexist:</tt> can be used to check if a file has been uploaded to the repository, but not to the wiki itself:
 * <tt> </tt>  → 
 * <tt> </tt> → 
 * <tt> </tt> → 

If a local description page has been created for the file, the result is exists for all of the above.

#rel2abs
This function converts a relative file path into an absolute filepath.


 * <tt> </tt>
 * <tt> </tt>

Within the <tt>path</tt> input, the following syntax is valid:
 * → the current level
 * → "go up one level"
 * → "go down one level into the subdirectory /foo"

If the <tt>base path</tt> is not specified, the full page name of the page will be used instead:


 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''

Invalid syntax, such as <tt>/.</tt> or <tt>/./</tt>, is ignored. Since no more than two consecutive full stops are permitted, sequences such as these can be used to separate successive statements:


 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''

#switch
This function compares one input value against several test cases, returning an associated Ausdruck if a match is found.

Example:


 * <tt> </tt> →   


 * 1) switch allows an editor to add information in one template and this information will be visible in several other templates which all have different formatting.

Default
The <tt>default result</tt> is returned if no <tt>case</tt> Ausdruck matches the <tt>comparison Ausdruck</tt>:


 * <tt> </tt> →   

In this syntax, the default result must be the last parameter and must not contain a raw equals sign.


 * <tt> </tt> →   < ! - - do not remove the spaces between «  » - - >
 * <tt> </tt> →   < ! - - do not remove the spaces between «  » - - >

Alternatively, the default result may be explicitly declared with a <tt>case</tt> Ausdruck of "<tt>#default</tt>".

Default results declared in this way may be placed anywhere within the function:


 * <tt> </tt> →   

If the <tt>default</tt> parameter is omitted and no match is made, no <tt>result</tt> is returned:


 * <tt> </tt> →   < ! - - do not remove the spaces between «  » - - >

Grouping results
It is possible to have 'fall through' values, where several <tt>case</tt> Ausdrucks return the same <tt>result</tt> Ausdruck. This minimizes duplication.

Here cases 2, 3 and 4 all return <tt>result2</tt>; cases 6 and 7 both return <tt>result4</tt>

Comparison behaviour
As with <tt>#ifeq</tt>, the comparison is made numerically if both the comparison Ausdruck and the case Ausdruck being tested are numeric; or as a case-sensitive Ausdruck otherwise:


 * <tt> </tt> → 
 * <tt> </tt> → 


 * <tt> </tt> → 
 * <tt> </tt> → 

A <tt>case</tt> Ausdruck may be empty:
 * <tt> </tt> → 

Once a match is found, subsequent <tt>cases</tt> are ignored:
 * <tt> </tt> → 

Raw equal signs
"Case" Ausdrucks cannot contain raw equals signs. To work around this, create a template = containing a single equals sign: <tt>=</tt>.

Example:


 * <tt> </tt> → 

For a simple real life example of the use of this function, check. A complex example can be found at.

#time
This parser function takes a date and/or time (in the Gregorian calendar) and formats it according to the syntax given. A date/time object can be specified; the default is the value of the magic word <tt> </tt> – that is, the time the page was last rendered into HTML.


 * <tt> </tt>
 * <tt> </tt>

The list of accepted formatting codes is given in the table to the right. Any character in the formatting Ausdruck that is not recognised is passed through unaltered; this applies also to blank spaces (the system does not need them for interpreting the codes). There are also two ways to escape characters within the formatting Ausdruck: In addition, the digraph <tt>xx</tt> is interpreted as a single literal "x".
 * 1) A backslash followed by a formatting character is interpreted as a single literal character
 * 2) characters enclosed in double quotes are considered literal characters, and the quotes are removed


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 

The <tt>date/time object</tt> can be in any format accepted by PHP's strtotime function. Both absolute (eg <tt>20 December 2000</tt>) and relative (eg <tt>+20 hours</tt>) times are accepted.

<tt> </tt> → '''

<tt> </tt> → '''

<tt> </tt> → '''

If you've calculated a Unix timestamp, you may use it in date calculations by pre-pending an <tt>@</tt> symbol.

<tt> </tt> → '''

<tt> </tt> → '''

Full or partial absolute dates can be specified; the function will 'fill in' parts of the date that are not specified using the current values:


 * <tt> </tt> → '''

A four-digit number is interpreted as hours and minutes if possible, and otherwise as year:

<tt> </tt> → ''' Input is treated as a time rather than a year.

<tt> </tt> → ''' Since 19:60 is not a valid time, 1960 is treated as a year.

A six-digit number is interpreted as hours, minutes and seconds if possible, but otherwise as an error (not, for instance, a year and month):

<tt> </tt> → ''' Input is treated as a time rather than a year+month code.

<tt> </tt> → ''' Although 19:60:09 is not a valid time, 196009 is not interpreted as September 1960.

The function performs a certain amount of date mathematics:


 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''
 * <tt> </tt> → '''

The total length of the format Ausdrucks of the calls of  is limited to 6000 characters.

#timel
This function is identical to <tt> </tt>, except that it uses the local time of the wiki (as set in ) when no date is given.


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 

#titleparts
This function separates a pagetitle into segments based on slashes, then returns some of those segments as output.


 * <tt> </tt>

If the <tt>number of segments</tt> parameter is not specified, it defaults to "0", which returns all the segments. If the <tt>first segment</tt> parameter is not specified or is "0", it defaults to "1":


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 

Negative values are accepted for both values. Negative values for <tt>number of segments</tt> effectively 'strips' segments from the end of the Ausdruck. Negative values for <tt>first segment</tt> translates to "add this value to the total number of segments", loosely equivalent to "count from the right":


 * <tt> </tt> → 
 * <tt> </tt> →  
 * <tt> </tt> →   Strips one segment from the end of the Ausdruck, then returns the second segment and beyond

The Ausdruck is split a maximum of 25 times; further slashes are ignored. The Ausdruck is also limited to 255 characters, as it is treated as a page title:


 * <tt> </tt> → 

You can use #titleparts as a small "Ausdruck parser & converter", but consider that it returns the first subAusdruck capitalized. If lower case is needed, use lc: function to control output.


 * <tt> </tt> → 
 * <tt> </tt> → 
 * <tt> </tt> → 

Substitution
Parser functions can be substituted by prefixing the hash character with <tt>subst:</tt>:


 * <tt> </tt> → the code <tt>    </tt> will be inserted in the wikitext since the page  exists.

Tables
Parser functions will mangle wikitable syntax, treating all the raw pipe characters as parameter divisors. To avoid this, most wikis create the template    :! with its contents only a raw pipe character. This 'hides' the pipe from the MediaWiki parser, ensuring that it is not considered until after all the templates and variables on a page have been expanded. Alternatively, raw HTML table syntax can be used, although this is less intuitive and more error-prone.

Stripping whitespace
Whitespace, including newlines, tabs, and spaces, is stripped from the beginning and end of all the parameters of these parser functions. If this is not desirable, comparison of Ausdrucks can be done after putting them in quotation marks.





For preventing trimming then- and else-parts, see m:Template:If.