Ayuda:Extensión:ParserFunctions

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La extensión Extensión:ParserFunctions brinda once funciones del analizador sintáctico que suplementan el "magic words ", que ya están presentes en MediaWiki. (Es posible que sea configurado para proporcionar funciones de analizador adicionales para el manejo de cadenas; estas funciones de cadena están documentadas elsewhere .) Todas las parser functions proporcionadas por esta extensión tienen la forma:

{{#functionname: argumento 1 | argumento 2 | argumento 3 ... }}

#expr

Tipo Operadores
Agrupadores (paréntesis) ( )
Números 1234.5   e (2.718)   pi (3.142)
operador binario e   unario +,-
Unario not ceil trunc floor abs exp ln sin cos tan acos asin atan
Binarios ^
* / div mod
+ -
Redondeo round
Lógicos = != <> > < >= <=
and
or

Esta función, evalúa una expresión matemática, y devuelve el resultado. Esta función está también disponible en Scribunto por medio de la función mw.ext.ParserFunctions.expr.

{{#expr: expresión }}

Los operadores disponibles están listados a continuación, en orden de preferencia. Para más información sobre la sintaxis y uso de cada operador, se puede consultar la documentación (en inglés) Help:Calculation. La exactitud y el formato del resultado devuelto, depende del sistema operativo del servidor que ejecuta la wiki, y el formáto numérico que use el servidor

Cuando se evalúa usando algebra booleana, el cero evalúa a falso, y cualquier valor diferente de cero, positivo o negativo, evalúa a verdadero:

{{#expr: 1 and -1 }}1
{{#expr: 1 and 0 }}0
{{#expr: 1 or -1 }}1
{{#expr: -1 or 0 }}1
{{#expr: 0 or 0 }}0

Una expresión de entrada vacía regresa una cuerda vacía. Las expresiones nulas regresan algún mensaje de error entre muchos, los cuales pueden ser detectados utilizando el #iferror función:

{{#expr: }}
{{#expr: 1+ }}Expression error: Missing operand for +.
{{#expr: 1 = }}Expression error: Missing operand for =.
{{#expr: 1 foo 2 }}Expression error: Unrecognized word "foo".

El orden de los operandos de adición y de sustracción antes o después de un número es significativo y puede ser tratado como valor positivo o negativo en vez de un operando con una entrada errónea:

{{#expr: +1 }}1
{{#expr: -1 }}-1
{{#expr: + 1 }}1
{{#expr: - 1 }}-1

Nota, si utilizas las palabras mágicas, tienes que formatearlas en crudo para sacar comas y traducir los números. Por ejemplo, {{NUMBEROFUSERS}} resultados en 17 289 686ado, donde queremos 17289686, los cuales pueden ser obtenidos utilizando {{formatnum :{{NUMBEROFUSERS}}|R}}. Esto es especialmente importante en algunos lenguajes donde los números están traducidos. Por ejemplo, en Bengali, {{NUMBEROFUSERS}} productos ৩০,০৬১.

{{#expr:{{NUMBEROFUSERS}}+100}} Expression error: Unrecognized punctuation character " ".
{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}17289786
Advertencia Advertencia: El operador mod da resultados incorrectos para algunos valores del segundo argumento:
{{#expr: 123 mod (2^64-1)}}Division by zero. (Produce una cuerda vacía; debería ser 123)
Si quieres hacer los cálculos basaron en fechas (Por ej., prueba si la fecha y hora actuales están después de alguna otra fecha y hora), primero convierte el tiempo a segundos después del 1 de enero de 1970, utilizando $tiempo, entonces sencillamente puedes añadir y restar fechas como números.

Redondeo

Rounds del número a la izquierda a un múltiplo de 1/10 elevado a una potencia, con el exponente igual al valor truncado del número dado a la derecha.

Para redondear hacia arriba o hacia abajo, use la unaria ceil o $piso respectivamente.

Caso de prueba Resultado Método de redondeo
{{#expr: 1/3 round 5 }} 0.33333 El dígito final es <5, por lo que no se produce redondeo aparente
{{#expr: 1/6 round 5 }} 0.16667 El dígito final es ≥ 5, por lo que se redondea
{{#expr: 8.99999/9 round 5 }} 1 Nuevamente, el resultado se redondea en el último dígito, lo que resulta en un redondeo adicional
{{#expr: 1234.5678 round -2 }} 1200 Redondeado a 100 aproximadamente porque los valores negativos se redondean a la izquierda del punto decimal
{{#expr: 1234.5678 round 2 }} 1234.57 Redondeado a la centésima aproximada porque los valores positivos se redondean a la derecha del punto decimal
{{#expr: 1234.5678 round 2.3 }} 1234.57 Los decimales en el índice de redondeo no hacen ninguna diferencia en el resultado redondeado
{{#expr: trunc 1234.5678 }} 1234 Porción decimal truncada (cortada)
Redondeo al entero aproximado
{{#expr: 1/3 round 0 }} 0 Abajo al entero aproximado, que es cero
{{#expr: 1/2 round 0 }} 1 Hasta el entero aproximado, que es uno
{{#expr: 3/4 round 0 }} 1 Hasta el entero aproximado, que es uno
{{#expr: -1/3 round 0 }} -0 Hasta el entero aproximado, que es cero
{{#expr: -1/2 round 0 }} -1 Abajo al entero aproximado, que es negativo
{{#expr: -3/4 round 0 }} -1 Abajo al entero aproximado, que es negativo
Redondeando hacia arriba o hacia abajo con ceil y floor
{{#expr: ceil(1/3) }} 1 Hasta el siguiente entero máximo, que es uno
{{#expr: floor(1/3) }} 0 Abajo al siguiente entero mínimo, que es cero
{{#expr: ceil(-1/3) }} -0 Hasta el siguiente entero máximo, que es cero
{{#expr: floor(-1/3) }} -1 Abajo al siguiente entero mínimo, que es negativo
{{#expr: ceil 1/3 }} 0.33333333333333 No redondeado, ya que 1 ya es un entero
Advertencia Advertencia: Interpretado como (ceil 1)/3, no como ceil(1/3), como es de esperar

Cadenas

Las expresiones solo funcionan con valores numéricos, no pueden comparar cadenas o caracteres. #ifeq puede ser usado en su lugar.

{{#expr: "a" = "a" }}Expression error: Unrecognized punctuation character """.
{{#expr: a = a }}Expression error: Unrecognized word "a".
{{#ifeq: a | a | 1 | 0 }}1

#if

Esta función evalúa una cadena de prueba y determina si está vacía o no. Una cadena de prueba que contiene solo espacios en blanco se considera vacía.

{{#if: cadena de prueba | evaluar si la cadena de prueba no está vacía | evaluar si la cadena de prueba está vacía (o solo espacio en blanco) }}
{{#if: primer parámetro | segundo parámetro | tercer parámetro }}

Esta función primero prueba si el primer parámetro no está vacío. Si el primer parámetro no está vacío, la función muestra el segundo argumento. Si el primer parámetro está vacío o contiene solo caracteres de espacios en blanco (espacios, nuevas líneas, etc.), se muestra el tercer argumento.

{{#if: | yes | no}}no
{{#if: string | yes | no}}yes
{{#if:      | yes | no}}no
{{#if:


| yes | no}}
no

La cadena de prueba siempre se interpreta como texto puro, por lo que las expresiones matemáticas no se evalúan:

{{#if: 1==2 | yes | no }}yes
{{#if: 0 | yes | no }}yes

El último parámetro (falso) se puede omitir:

{{#if: foo | yes }} yes
{{#if: | yes }}
{{#if: foo | | no}}

La función puede ser insertada. Para hacerlo, anide la función #if interna en su forma completa en lugar de un parámetro de la función #if adjunta. Es posible hasta siete niveles de anidamiento, aunque eso puede depender de la wiki o del límite de memoria.

{{#if: cadena de prueba | evaluar si la cadena de prueba no está vacía | {{#if: cadena de prueba | evaluar si la cadena de prueba no está vacía | evaluar si la cadena de prueba está vacía (o solo espacio en blanco) }} }}

También puede usar un parámetro como la cadena de prueba en su declaración #if. Debe asegurarse de agregar | (símbolo pipe) después del nombre de la variable. (De modo que si el parámetro no tiene un valor, se evalúa como una cadena vacía en lugar de la cadena "{{{1}}}").

{{#if:{{{1|}}}|Ingresó texto en la variable 1|No hay texto en la variable 1 }}

Veasé Help:Parser functions in templates para más ejemplos de esta función.

#ifeq

Esta función de analizador compara dos cadenas de entrada, determina si son idénticas y devuelve una de las dos cadenas según el resultado. Si se requieren más comparaciones y cadenas de salida, considere usar #switch.

{{#ifeq: string 1 | string 2 | value if identical | value if different }}

Si ambas cadenas son valores numéricos válidos, las cadenas se comparan numéricamente:

{{#ifeq: 01 | 1 | equal | not equal}}equal
{{#ifeq: 0 | -0 | equal | not equal}}equal
{{#ifeq: 1e3 | 1000 | equal | not equal}}equal
{{#ifeq: {{#expr:10^3}} | 1000 | equal | not equal}}equal

De lo contrario, la comparación se hace como texto; esta comparación es sensible a mayúsculas y minúsculas:

{{#ifeq: foo | bar | equal | not equal}}not equal
{{#ifeq: foo | Foo | equal | not equal}}not equal
{{#ifeq: "01" | "1" | equal | not equal}}not equal  (compare con el ejemplo similar anterior, sin las comillas)
{{#ifeq: 10^3 | 1000 | equal | not equal}}not equal  (compárese con el ejemplo similar anterior, con #expr devolviendo un número válido primero)

Como ejemplo práctico, considere una template existente Template:Timer usando el analizador para elegir entre dos tiempos estándar, corto y largo. Toma el parámetro como la primera entrada para compararlo con la cadena "short": no existe una convención para el orden, pero es más fácil de leer si el parámetro va primero. El código de la plantilla se define como:

{{#ifeq: {{{1|}}} | short | 20 | 40 }}

se produce lo siguiente:

{{timer|short}}20
{{timer|20}}40
{{timer}}40
Advertencia Advertencia: #ifexpr no informa comparaciones numéricas equivalentes con los analizadores #ifeq y #switch. Estos dos últimos son más precisos que #ifexpr, y no devuelven resultados equivalentes. Considere estas comparaciones con el último dígito modificado:
{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}not equal
{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}not equal

Debido a que PHP usado en #ifeq y #switch compara dos números de tipo entero, devuelve el resultado esperado correctamente. Mientras que con #ifexpr y los mismos números:

{{#ifexpr: 12345678901234567 = 12345678901234568 | equal | not equal}}equal

Con el dígito diferente, el resultado de igual es realmente incorrecto.

Este comportamiento en #ifexpr se debe a que MediaWiki convierte números literales en expresiones a tipo flotante, lo que, para enteros grandes como estos, implica redondeo.

Advertencia Advertencia: Cuando se usan dentro de una función de analizador, cualquier etiqueta de analizador y otras funciones de analizador deben reemplazarse temporalmente con un código único . Esto afecta a las comparaciones:
{{#ifeq: <nowiki>foo</nowiki> | <nowiki>foo</nowiki> | equal | not equal}}not equal
{{#ifeq: <math>foo</math> | <math>foo</math> | equal | not equal}}not equal
{{#ifeq: {{#tag:math|foo}} | {{#tag:math|foo}} | equal | not equal}}not equal
{{#ifeq: [[foo]] | [[foo]] | equal | not equal}}equal
Si las cadenas que se comparan se dan como llamadas iguales a la misma plantilla que contiene dichas etiquetas, entonces la condición es verdadera, pero en el caso de dos plantillas con contenido idéntico que contienen dichas etiquetas, es falsa.
Advertencia Advertencia: Las comparaciones literales con magic words de nombre de página pueden fallar según la configuración del sitio. Por ejemplo, {{FULLPAGENAME}}, dependiendo de la wiki, puede usar mayúsculas en la primera letra y reemplazará todos los guiones bajos con espacios.

Para evitar esto, aplique la palabra mágica a ambos parámetros:

{{#ifeq: {{FULLPAGENAME: L'Aquila}} | {{FULLPAGENAME}} | equal | not equal}}equal

#iferror

Esta función toma una cadena de entrada y devuelve uno de los dos resultados; la función se evalúa como true si la cadena de entrada contiene un objeto HTML con class="error", como lo generan otras funciones del analizador como #expr, #time y #rel2abs, errores template como bucles y recursiones, y otros errores del analizador "failoft".

{{#iferror: test string | value if error | value if correct }}

Se pueden omitir una o ambas cadenas de retorno. Si se omite la cadena correcto, se devuelve la cadena de prueba si no es errónea. Si la cadena error también se omite, se devuelve una cadena vacía en caso de error:

{{#iferror: {{#expr: 1 + 2 }} | error | correct }}correct
{{#iferror: {{#expr: 1 + X }} | error | correct }}error
{{#iferror: {{#expr: 1 + 2 }} | error }}3
{{#iferror: {{#expr: 1 + X }} | error }}error
{{#iferror: {{#expr: 1 + 2 }} }}3
{{#iferror: {{#expr: 1 + X }} }}
{{#iferror: {{#expr: . }} | error | correct }}correct
{{#iferror: <strong class="error">a</strong> | error | correct }}error

#ifexpr

Esta función evalúa una expresión matemática y devuelve una de dos cadenas dependiendo del valor booleano del resultado:

{{#ifexpr: expression | value if true | value if false }}

La entrada expresión se evalúa exactamente como para #expr arriba, con los mismos operadores disponibles. La salida se evalúa como una expresión booleana.

Una expresión de entrada vacía evalúa false:

{{#ifexpr: | yes | no}}no

Como se mencionó anteriormente, cero se evalúa como false y cualquier valor distinto de cero se evalúa como true, por lo que esta función es equivalente a una que usa #ifeq y #expr solamente:

{{#ifeq: {{#expr: expression }} | 0 | value if false | value if true }}

excepto para una expresión de entrada vacía o incorrecta (un mensaje de error se trata como una cadena vacía; no es igual a cero, por lo que obtenemos valor si es verdadero).

{{#ifexpr: = | yes | no }} Expression error: Unexpected = operator.

comparando

{{#ifeq: {{#expr: = }} | 0 | no | yes }} yes

Cualquiera o ambos valores de retorno pueden omitirse; no se da salida cuando la rama apropiada se deja vacía:

{{#ifexpr: 1 > 0 | yes }}yes
{{#ifexpr: 1 < 0 | yes }}
{{#ifexpr: 0 = 0 | yes }} yes
{{#ifexpr: 1 > 0 | | no}}
{{#ifexpr: 1 < 0 | | no}} no
{{#ifexpr: 1 > 0 }}

#ifexist

Esta función toma una cadena de entrada, la interpreta como el título de una página y devuelve uno de los dos valores dependiendo de si la página existe o no en el wiki local.

{{#ifexist: page title | value if exists | value if doesn't exist }}

The function evaluates to true 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.

{{#ifexist: Help:Extension:ParserFunctions/es | exists | doesn't exist }}exists
{{#ifexist: XXHelp:Extension:ParserFunctions/esXX | exists | doesn't exist }}doesn't exist

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

{{#ifexist: Special:Watchlist | exists | doesn't exist }}exists
{{#ifexist: Special:CheckUser | exists | doesn't exist }}exists (because the Checkuser extension is installed on this wiki)
{{#ifexist: MediaWiki:Copyright | exists | doesn't exist }}exists (because MediaWiki:Copyright has been customized)

If a page checks a target using #ifexist:, then that page will appear in the Special:WhatLinksHere list for the target page. So if the code {{#ifexist:Foo }} were included live on this page (Help:Extension:ParserFunctions/es), Special:WhatLinksHere/Foo will list Help:Extension:ParserFunctions/es.

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

{{#ifexist: File:Example.png | exists | doesn't exist }}doesn't exist
{{#ifexist: Image:Example.png | exists | doesn't exist }}doesn't exist
{{#ifexist: Media:Example.png | exists | doesn't exist }}exists

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

#ifexist: does not work with interwiki links.

Límites de ifexist

#ifexist: 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, any further #ifexist: functions automatically return false, whether the target page exists or not, and the page is categorized into Category:Pages with too many expensive parser function calls. The name of the tracking category may vary depending on the content language of your wiki.

For some use cases it is possible to emulate the ifexist effect with css, by using the selectors a.new (to select links to unexisting pages) or a:not(.new) (to select links to existing pages). Furthermore, since the number of expensive parser functions that can be used on a single page is controlled by $wgExpensiveParserFunctionLimit , one can also increase the limit in LocalSettings.php if needed.

ifexist and wanted pages

A page that does not exist and is tested for using #ifexist will end up on the Wanted Pages.

#rel2abs

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

{{#rel2abs: path }}
{{#rel2abs: path | base path }}

Within the path input, the following syntax is valid:

  • . → the current level
  • .. → go up one level
  • /foo → go down one level into the subdirectory /foo

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

{{#rel2abs: /quok | Help:Foo/bar/baz }}Help:Foo/bar/baz/quok
{{#rel2abs: ./quok | Help:Foo/bar/baz }}Help:Foo/bar/baz/quok
{{#rel2abs: ../quok | Help:Foo/bar/baz }}Help:Foo/bar/quok
{{#rel2abs: ../. | Help:Foo/bar/baz }}Help:Foo/bar

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

{{#rel2abs: ../quok/. | Help:Foo/bar/baz }}Help:Foo/bar/quok
{{#rel2abs: ../../quok | Help:Foo/bar/baz }}Help:Foo/quok
{{#rel2abs: ../../../quok | Help:Foo/bar/baz }}quok
{{#rel2abs: ../../../../quok | Help:Foo/bar/baz }}Error: Invalid depth in path: "Help:Foo/bar/baz/../../../../quok" (tried to access a node above the root node).

#switch

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

{{#switch: comparison string
 | case = result
 | case = result
 | ...
 | case = result
 | default result
}}

Ejemplos:

{{#switch: baz | foo = Foo | baz = Baz | Bar }} Baz
{{#switch: foo | foo = Foo | baz = Baz | Bar }} Foo
{{#switch: zzz | foo = Foo | baz = Baz | Bar }} Bar

#switch with partial transclusion tags can effect a configuration file that enables an editor unfamiliar with template coding to view and edit configurable elements.

Predeterminado

The default result is returned if no case string matches the comparison string:

{{#switch: test | foo = Foo | baz = Baz | Bar }} Bar

In this syntax, the default result must be the last parameter and must not contain a raw equals sign (an equals sign without {{}}). If it does, it will be treated as a case comparison, and no text will display if no cases match. This is because the default value has not been defined (is empty). If a case matches however, its associated string will be returned.

{{#switch: test | Bar | foo = Foo | baz = Baz }} →
{{#switch: test | foo = Foo | baz = Baz | B=ar }} →
{{#switch: test | test = Foo | baz = Baz | B=ar }} → Foo

Alternatively, the default result may be explicitly declared with a case string of "#default".

{{#switch: comparison string
 | case = result
 | case = result
 | ...
 | case = result
 | #default = default result
}}

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

{{#switch: test | foo = Foo | #default = Bar | baz = Baz }} Bar

If the default parameter is omitted and no match is made, no result is returned:

{{#switch: test | foo = Foo | baz = Baz }}

Agrupando resultados

It is possible to have 'fall through' values, where several case strings return the same result string. This minimizes duplication.

{{#switch: comparison string
 | case1 = result1
 | case2 
 | case3 
 | case4 = result234
 | case5 = result5
 | case6 
 | case7 = result67
 | #default = default result
}}

Here cases 2, 3 and 4 all return result234; cases 6 and 7 both return result67. The "#default = " in the last parameter may be omitted in the above case.

Use with parameters

The function may be used with parameters as the test string. In this case, it is not necessary to place the pipe after the parameter name, because it is very unlikely that you will choose to set a case to be the string "{{{parameter name}}}". (This is the value the parameter will default to if the pipe is absent and the parameter doesn't exist or have a value. See Help:Parser functions in templates .)

{{#switch: {{{1}}} | foo = Foo | baz = Baz | Bar }}

In the above case, if {{{1}}} equals foo, the function will return Foo. If it equals baz, the function will return Baz. If the parameter is empty or does not exist, the function will return Bar.

As in the section above, cases can be combined to give a single result.

{{#switch: {{{1}}} | foo | zoo | roo = Foo | baz = Baz | Bar }}

Here, if {{{1}}} equals foo, zoo or roo, the function will return Foo. If it equals baz, the function will return Baz. If the parameter is empty or does not exist, the function will return Bar.

Additionally, the default result can be omitted if you do not wish to return anything if the test parameter value does not match any of the cases.

{{#switch: {{{1}}} | foo = Foo | bar = Bar }}

In this case, the function returns an empty string unless {{{1}}} exists and equals foo or bar, in which case it returns Foo or Bar, respectively.

This has the same effect as declaring the default result as empty.

{{#switch: {{{1}}} | foo | zoo | roo = Foo | baz = Baz | }}

If for some reason you decide to set a case as "{{{parameter name}}}", the function will return that case's result when the parameter doesn't exist or doesn't have a value. The parameter would have to exist and have a value other than the string "{{{parameter name}}}" to return the function's default result.

(when {{{1}}} doesn't exist or is empty):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Foo
(when {{{1}}} has the value "test"):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Bar
(when {{{1}}} has the value "{{{1}}}"):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Foo

In this hypothetical case, you would need to add the pipe to the parameter ({{{1|}}}).

Comparison behavior

As with #ifeq, the comparison is made numerically if both the comparison string and the case string being tested are numeric; or as a case-sensitive string otherwise:

{{#switch: 0 + 1 | 1 = one | 2 = two | three}} → three
{{#switch: {{#expr: 0 + 1}} | 1 = one | 2 = two | three}} → one
{{#switch: a | a = A | b = B | C}} → A
{{#switch: A | a = A | b = B | C}} → C

A case string may be empty:

{{#switch: | = Nothing | foo = Foo | Something }}Nothing

Once a match is found, subsequent cases are ignored:

{{#switch: b | f = Foo | b = Bar | b = Baz | }}Bar
Advertencia Advertencia: Las comparaciones numéricas con #switch y #ifeq no son equivalentes con las comparaciones en las expresiones (véase también arriba):
{{#switch: 12345678901234567 | 12345678901234568 = A | B}} → B
{{#ifexpr: 12345678901234567 = 12345678901234568 | A | B}} → A

Raw equal signs

"Case" strings cannot contain raw equals signs. To work around this, create a template {{=}} containing a single equals sign: =, or replace equals sign with html code &#61;.

Ejemplo:

{{#switch: 1=2
 | 1=2 = raw
 | 1<nowiki>=</nowiki>2 = nowiki
 | 1{{=}}2 = template
 | default
}}template


{{#switch: 1=2
 | 1&#61;2 = html
 | default
}}html
For a simple real life example of the use of this function, check Template:NBA color. Two complex examples can be found at Plantilla:Extensión and w:Template:BOTREQ.

Replacing #ifeq

#switch can be used to reduce expansion depth.

Por ejemplo:

  • {{#switch:{{{1}}} |condition1=branch1 |condition2=branch2 |condition3=branch3 |branch4}}

es equivalente a:

  • {{#ifeq:{{{1}}}|condition1 |branch1 |{{#ifeq:{{{1}}}|condition2 |branch2 |{{#ifeq:{{{1}}}|condition3 |branch3 |branch4}}}}}}

i.e. deep nesting, linear:

{{#ifeq:{{{1}}}|condition1
  |<!--then-->branch1
  |<!--else-->{{#ifeq:{{{1}}}|condition2
                |<!--then-->branch2
                |<!--else-->{{#ifeq:{{{1}}}|condition3
                              |<!--then-->branch3
                              |<!--else-->branch4}}}}}}

On the other hand, the switch replacement could be complicated/impractical for IFs nested in both branches (shown with alternatives of indentation, indented on both sides), making full symmetrical tree:

{{#ifeq:{{{1}}}|condition1
 |<!--then-->branch1t{{
  #ifeq:{{{1}}}|condition2
   |<!--then-->branch1t2t{{#ifeq:{{{1}}}|condition4|<!--then-->branch1t2t4t|<!--else-->branch1t2t4e}}
   |<!--else-->branch1t2e{{#ifeq:{{{1}}}|condition5|<!--then-->branch1t2e5t|<!--else-->branch1t2e5e}}
  }}
 |<!--else-->branch1e{{#ifeq:{{{1}}}|condition3
   |<!--then-->branch1e3t{{#ifeq:{{{1}}}|condition6|branch1e3t6t|branch1e3t6e}}
   |<!--else-->branch1e3e{{
    #ifeq:{{{1}}}|condition7
     |branch1e3e7t
     |branch1e3e7t
    }}
  }}
}}

#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 {{CURRENTTIMESTAMP}} – that is, the time the page was last rendered into HTML.

{{#time: format string }}
{{#time: format string | date/time object }}
{{#time: format string | date/time object | language code }}
{{#time: format string | date/time object | language code | local }}

The list of accepted formatting codes is given in the table to the right. Any character in the formatting string that is not recognized 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 string:

  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.

In addition, the digraph xx is interpreted as a single literal "x".

{{#time: Y-m-d }}2020-03-30
{{#time: [[Y]] m d }}2020 03 30
{{#time: [[Y (year)]] }}2020 (20UTCamMon, 30 Mar 2020 07:14:53 +0000)
{{#time: [[Y "(year)"]] }}2020 (year)
{{#time: i's" }}14'53"

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

{{#time: r|now}}Mon, 30 Mar 2020 07:14:53 +0000
{{#time: r|+2 hours}}Mon, 30 Mar 2020 09:14:53 +0000
{{#time: r|now + 2 hours}}Mon, 30 Mar 2020 09:14:53 +0000
{{#time: r|20 December 2000}}Wed, 20 Dec 2000 00:00:00 +0000
{{#time: r|December 20, 2000}}Wed, 20 Dec 2000 00:00:00 +0000
{{#time: r|2000-12-20}}Wed, 20 Dec 2000 00:00:00 +0000
{{#time: r|2000 December 20}}Error: Invalid time.

The language code in ISO 639-3 (?) allows the string to be displayed in the chosen language

{{#time:d F Y|1988-02-28|nl}}28 februari 1988
{{#time:l|now|uk}}понеділок
{{#time:d xg Y|20 June 2010|pl}}20 czerwca 2010

The local parameter specifies if the date/time object refers to the local timezone or to UTC.

This is a boolean parameters: its value is determined by casting the value of the argument (see the official PHP documentation for details on how string are cast to boolean values).

Please note that, if the variable $wgLocaltimezone is set to UTC, there is no difference in the output when local is set to true or false.

See the following examples for details:

{{#time: Y F d H:i:s|now|it|0}}2020 marzo 30 07:14:53
{{#time: Y F d H:i:s|now|it|1}}2020 marzo 30 07:14:53
{{#time: Y F d H:i:s|+2 hours||0}}2020 marzo 30 09:14:53
{{#time: Y F d H:i:s|+2 hours||1}}2020 marzo 30 09:14:53
{{#time:c|2019-05-16T17:05:43+02:00|it}}2019-05-16T15:05:43+00:00
{{#time:c|2019-05-16T17:05:43+02:00|it|0}}2019-05-16T15:05:43+00:00
{{#time:c|2019-05-16T17:05:43+02:00|it|true}}2019-05-16T15:05:43+00:00

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

{{#time: U | now }}1585552493
{{#time: r | @1585552493 }}Mon, 30 Mar 2020 07:14:53 +0000
Advertencia Advertencia: Without the @ prefix before numeric timestamp values, the result is an error most of the time, or is an unexpected value:
{{#time: r | 1970-01-01 00:16:39 }}Thu, 01 Jan 1970 00:16:39 +0000
{{#time: U | 1970-01-01 00:16:39 }}999
{{#time: r | @999 }}Thu, 01 Jan 1970 00:16:39 +0000 (correct)
{{#time: r | 999 }}Error: Invalid time. (unsupported year format)
{{#time: r | 1970-01-01 00:16:40 }}Thu, 01 Jan 1970 00:16:40 +0000
{{#time: U | 1970-01-01 00:16:40 }}1000
{{#time: r | @1000 }}Thu, 01 Jan 1970 00:16:40 +0000 (correct)
{{#time: r | 1000 }}Sun, 30 Mar 1000 00:00:00 +0000 (interpreted as a year with current month and day of the month)
{{#time: r | 1970-01-01 02:46:39 }}Thu, 01 Jan 1970 02:46:39 +0000
{{#time: U | 1970-01-01 02:46:39 }}9999
{{#time: r | @9999 }}Thu, 01 Jan 1970 02:46:39 +0000 (correct)
{{#time: r | 9999 }}Tue, 30 Mar 9999 00:00:00 +0000 (interpreted as a year with current month and day of the month)
{{#time: r | 1970-01-01 02:46:40 }}Thu, 01 Jan 1970 02:46:40 +0000
{{#time: U | 1970-01-01 02:46:40 }}10000
{{#time: r | @10000 }}Thu, 01 Jan 1970 02:46:40 +0000 (correct)
{{#time: r | 10000 }}Error: Invalid time. (unsupported year format)
Advertencia Advertencia: The range of acceptable input is 1 January 0111 → 31 December 9999. For the years 100 through 110 the output is inconsistent, Y and leap years are like the years 100-110, r, D, l and U are like interpreting these years as 2000-2010.
{{#time: d F Y | 29 Feb 0100 }}01 marzo 0100
(correct, no leap year), but
{{#time: r | 29 Feb 0100 }}Mon, 01 Mar 0100 00:00:00 +0000 (wrong, even if 100 is interpreted as 2000, because that is a leap year)
{{#time: d F Y | 15 April 10000 }}Error: Invalid time.
{{#time: r | 10000-4-15 }}Sat, 15 Apr 2000 10:00:00 +0000

Year numbers 0-99 are interpreted as 2000-2069 and 1970-1999, except when written in 4-digit format with leading zeros:

{{#time: d F Y | 1 Jan 6 }}01 enero 2006
{{#time: d F Y | 1 Jan 06 }}01 enero 2006
{{#time: d F Y | 1 Jan 006 }}01 enero 2006
{{#time: d F Y | 1 Jan 0006 }}01 enero 0006 (4-digit format)
The weekday is supplied for the years 100-110 and from 1753, for the years 111-1752 the r-output shows "Unknown" and the l-output "<>". As a consequence, the r-output is not accepted as input for these years.

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:

{{#time: Y | January 1 }}2020
Advertencia Advertencia: The fill-in feature is not consistent; some parts are filled in using the current values, others are not:
{{#time: Y m d H:i:s | June }}2020 06 30 00:00:00 Gives the start of the day, but the current day of the month and the current year.
{{#time: Y m d H:i:s | 2003 }}2003 03 30 00:00:00 Gives the start of the day, but the current day of the year.

A four-digit number is always interpreted as a year, never as hours and minutes:[1]

{{#time: Y m d H:i:s | 1959 }}1959 03 30 00:00:00

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):

{{#time: Y m d H:i:s | 195909 }}2020 03 30 19:59:09 Input is treated as a time rather than a year+month code.
{{#time: Y m d H:i:s | 196009 }}Error: Invalid time. 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:

{{#time: d F Y | January 0 2008 }}31 diciembre 2007
{{#time: d F | January 32 }}Error: Invalid time.
{{#time: d F | February 29 2008 }}29 febrero
{{#time: d F | February 29 2007 }}01 marzo
{{#time:Y-F|now -1 months}}2020-marzo

The total length of the format strings of the calls of #time is limited to 6000 characters[2].

Time Zone issue

There is a bug in this #time parser function (more specifically in PHP DateTime) that does not allow the passing-in of non-integers as relative time zone offsets. This issue does not apply when using an on-the-hour time zone, such as EDT. For example:

  • {{#time:g:i A | -4 hours }} → 3:14 AM

However, India is on a +5.5 hours time offset from UTC, and thus using its time zone will not normally allow the correct calculation of a relative time zone offset. Here's what happens:

  • {{#time:g:i A | +5.5 hours }} → 7:14 AM

To workaround this issue, simply convert the time into minutes or seconds, like this:

  • {{#time:g:i A | +330 minutes }} → 12:44 PM
  • {{#time:g:i A | +19800 seconds }} → 12:44 PM

(Tim Starling, the developer of this function, provided the exact syntax for this solution.)

#timel

This function is identical to {{#time: ... }}, when the local parameter is set to true, so it always uses the local time of the wiki (as set in $wgLocaltimezone ).

Syntax of the function is:

{{#timel: format string }}
{{#timel: format string | date/time object }}
{{#timel: format string | date/time object | language code }}
Please note that, if the variable $wgLocaltimezone is set to UTC, there is no difference in the output when local is set to true or false
Example of the use of #time and #timel parser functions from a server where the timezone is not UTC

For instance, see the following examples:

{{#time:c|now|it}}2020-03-30T07:14:53+00:00
{{#time:c|now|it|0}}2020-03-30T07:14:53+00:00
{{#time:c|now|it|1}}2020-03-30T07:14:53+00:00
{{#timel:c|now|it}}2020-03-30T07:14:53+00:00
Advertencia Advertencia: Be aware that U for both time and timel will return the same number of seconds since 1970-01-01 00:00:00 UTC on Wikipedias with different timezones than UTC (formerly known as GMT)
U Unix time. Seconds since January 1 1970 00:00:00 GMT.
Z Timezone offset in seconds.
{{#time: U}}1585552493
{{#timel: U}}1585552493
{{#time: Z}}0
{{#timel: Z}}0

#titleparts

This function separates a page title into segments based on slashes, then returns some of those segments as output.

{{#titleparts: pagename | number of segments to return | first segment to return }}

If the number of segments to return parameter is not specified, it defaults to "0", which returns all the segments from the first segment to return (included). If the first segment to return parameter is not specified or is "0", it defaults to "1":

{{#titleparts: Talk:Foo/bar/baz/quok }}Talk:Foo/bar/baz/quok
{{#titleparts: Talk:Foo/bar/baz/quok | 1 }}Talk:Foo See also {{ROOTPAGENAME }}.
{{#titleparts: Talk:Foo/bar/baz/quok | 2 }}Talk:Foo/bar
{{#titleparts: Talk:Foo/bar/baz/quok | 2 | 2 }}bar/baz
{{#titleparts: Talk:Foo/bar/baz/quok | | 2 }}bar/baz/quok
{{#titleparts: Talk:Foo/bar/baz/quok | | 5 }}

Negative values are accepted for both values. Negative values for the number of segments to return parameter effectively 'strips' segments from the end of the string. Negative values for the first segment to return translates to "start with this segment counting from the right":

{{#titleparts: Talk:Foo/bar/baz/quok | -1 }}Talk:Foo/bar/baz Strips one segment from the end of the string. See also {{BASEPAGENAME}}.
{{#titleparts: Talk:Foo/bar/baz/quok | -4 }} Strips all 4 segments from the end of the string
{{#titleparts: Talk:Foo/bar/baz/quok | -5 }} Strips 5 segments from the end of the string (more than exist)
{{#titleparts: Talk:Foo/bar/baz/quok | | -1 }} quok Returns last segment. See also {{SUBPAGENAME}}.
{{#titleparts: Talk:Foo/bar/baz/quok | -1 | 2 }} bar/baz Strips one segment from the end of the string, then returns the second segment and beyond
{{#titleparts: Talk:Foo/bar/baz/quok | -1 | -2 }} baz Start copying at the second last element; strip one segment from the end of the string

Before processing, the pagename parameter is HTML-decoded: if it contains some standard HTML character entities, they will be converted to plain characters (internally encoded with UTF-8, i.e. the same encoding as in the MediaWiki source page using this parser function).

For example, any occurrence of &quot;, &#34;, or &#x22; in pagename will be replaced by ".
No other conversion from HTML to plain text is performed, so HTML tags are left intact at this initial step even if they are invalid in page titles.
Some magic keywords or parser functions of MediaWiki (such as {{PAGENAME }} and similar) are known to return strings that are needlessly HTML-encoded, even if their own input parameter was not HTML-encoded:

The titleparts parser function can then be used as a workaround, to convert these returned strings so that they can be processed correctly by some other parser functions also taking a page name in parameter (such as {{PAGESINCAT: }} but which are still not working properly with HTML-encoded input strings.

For example, if the current page is Category:Côte-d'Or, then:

  • {{#ifeq: {{FULLPAGENAME}} | Category:Côte-d'Or | 1 | 0 }}, and {{#ifeq: {{FULLPAGENAME}} | Category:Côte-d&apos;Or | 1 | 0 }} are both returning 1; (the #ifeq parser function does perform the HTML-decoding of its input parameters).
  • {{#switch: {{FULLPAGENAME}} | Category:Côte-d'Or = 1 | #default = 0 }}, and {{#switch: {{FULLPAGENAME}} | Category:Côte-d&apos;Or = 1 | #default = 0 }} are both returning 1; (the #switch parser function does perform the HTML-decoding of its input parameters).
  • {{#ifexist: {{FULLPAGENAME}} | 1 | 0 }}, {{#ifexist: Category:Côte-d'Or | 1 | 0 }}, or even {{#ifexist: Category:Côte-d&apos;Or | 1 | 0 }} will all return 1 if that category page exists (the #ifexist parser function does perform the HTML-decoding of its input parameters);
  • {{PAGESINCAT: Côte-d'Or }} will return a non-zero number, if that category contains pages or subcategories, but:
  • {{PAGESINCAT: {{CURRENTPAGENAME}} }}, may still unconditionally return 0, just like:
  • {{PAGESINCAT: {{PAGENAME|Category:Côte-d'Or}} }}
  • {{PAGESINCAT: {{PAGENAME|Category:Côte-d&apos;Or}} }}

The reason of this unexpected behavior is that, with the current versions of MediaWiki, there are two caveats:

  • {{FULLPAGENAME}}, or even {{FULLPAGENAME|Côte-d'Or}} may return the actually HTML-encoded string Category:Côte-d&apos;Or and not the expected Category:Côte-d'Or, and that:
  • {{PAGESINCAT: Côte-d&apos;Or }} unconditionally returns 0 (the PAGESINCAT magic keyword does not perform any HTML-decoding of its input parameter).

The simple workaround using titleparts (which will continue to work if the two caveats are fixed in a later version of MediaWiki) is:

  • {{PAGESINCAT: {{#titleparts: {{CURRENTPAGENAME}} }} }}
  • {{PAGESINCAT: {{#titleparts: {{PAGENAME|Category:Côte-d'Or}} }} }}
  • {{PAGESINCAT: {{#titleparts: {{PAGENAME|Category:Côte-d&apos;Or}} }} }}, that all return the actual number of pages in the same category.

Then the decoded pagename is canonicalized into a standard page title supported by MediaWiki, as much as possible:

  1. All underscores are automatically replaced with spaces:
    {{#titleparts: Talk:Foo/bah_boo|1|2}}bah boo Not bah_boo, despite the underscore in the original.
  2. The string is split a maximum of 25 times; further slashes are ignored and the 25th element will contain the rest of the string. The string is also limited to 255 characters, as it is treated as a page title:
    {{#titleparts: a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/aa/bb/cc/dd/ee | 1 | 25 }}y/z/aa/bb/cc/dd/ee
    If for whatever reason you needed to push this function to its limit, although very unlikely, it is possible to bypass the 25 split limit by nesting function calls:
    {{#titleparts: {{#titleparts: a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z/aa/bb/cc/dd/ee| 1 | 25 }} | 1 | 2}}z
  3. Finally the first substring is capitalized according to the capitalization settings of the local wiki (if that substring also starts by a local namespace name, that namespace name is also normalized).
    {{#titleparts: talk:a/b/c }}Talk:A/b/c
Advertencia Advertencia: You can use #titleparts as a small "string parser and converter", but consider that it returns the first substring capitalized:
{{#titleparts: one/two/three/four|1|1 }}One
{{#titleparts: one/two/three/four|1|2 }}two

If lower case is needed, use lc: function to control output:

{{lc: {{#titleparts: one/two/three/four|1|1 }} }}one

You can prepend a 'dummy' slash at the beginning of the string to get the correct first substring capitalization (uppercase or lowercase). Use 2 instead of 1 for first segment to return:

{{#titleparts: /one/two/three/four|1|2 }}one
{{#titleparts: /One/two/three/four|1|2 }}One
Advertencia Advertencia: Certain characters that are illegal in a page title will cause #titleparts to not parse the string:
{{#titleparts: {one/two} | 1 | 1 }}{one/two}. Does not produce the expected: {one
{{#titleparts: [[page]]/123 | 1 | 2 }}page/123. Does not work because brackets are illegal in page titles and this parser function does not process links embedded in its input pagename parameter, even when they use the MediaWiki syntax, or any other HTML or MediaWiki tags.
{{#titleparts: red/#00FF00/blue | 1 | 3 }} → "". Does not work because "#" is also illegal in page titles.
Advertencia Advertencia: If any part of the title is just "." or "..", #titleparts will not parse the string:
{{#titleparts: one/./three | 1 | 1 }}one/./three. The whole string is returned. It does not produce the expected: one
Advertencia Advertencia: This function does not degrade gracefully if the input exceeds 255 bytes in UTF-8. If the input string is 256 bytes or more, the whole string is returned.

StringFunctions

All of these functions (len, pos, rpos, sub, replace, explode) are integrated from the StringFunctions extension, but are only available if an administrator sets $wgPFEnableStringFunctions = true; in LocalSettings.php.

All of these functions operate in O(n) time complexity, making them safe against DoS attacks.

# Some parameters of these functions are limited through global settings to prevent abuse. See section Limits hereafter.
  1. For functions that are case sensitive, you may use the magic word {{lc:string}} as a workaround in some cases.
  2. To determine whether a MediaWiki server enables these functions, check the list of supported Extended parser functions in Special:Version.
  3. String length is limited by $wgPFStringLengthLimit variable, default to 1000.

#len:

The #len parser function was merged from the StringFunctions extension as of version 1.2.0

The #len function returns the length of the given string. The syntax is:

{{#len:string}}

The return value is always a number of characters in the source string (after expansions of template invocations, but before conversion to HTML). If no string is specified, the return value is zero.

* This function is safe with UTF-8 multibyte characters. Example:
    • {{#len:Žmržlina}}8
  • Leading and trailing spaces or newlines are not counted, but intermediate spaces and newlines are taken into account. Examples:
    • {{#len:Icecream }}8
    • {{#len: a   b }}5 - 3 spaces between 2 characters
  • Characters given by reference are not converted, but counted according to their source form.
    • {{#len:&nbsp;}}6 - named characters references
    • {{#len:&#32;}}5 - numeric characters references, not ignored despite it designates a space here.
  • Tags such as <nowiki> and other tag extensions will always have a length of zero, since their content is hidden from the parser. Example:
    • {{#len:<nowiki>This is a </nowiki>test}}4

#pos:

The #pos parser function was merged from the StringFunctions extension as of version 1.2.0

The #pos function returns the position of a given search term within the string. The syntax is:

{{#pos:string|search term|offset}}

The offset parameter, if specified, tells a starting position where this function should begin searching.

If the search term is found, the return value is a zero-based integer of the first position within the string.

If the search term is not found, the function returns an empty string.

* This function is case sensitive.
  • The maximum allowed length of the search term is limited through the $wgStringFunctionsLimitSearch global setting.
  • This function is safe with UTF-8 multibyte characters. Example: {{#pos:Žmržlina|žlina}} returns 3.
  • As with #len, <nowiki> and other tag extensions are treated as having a length of 1 for the purposes of character position. Example: {{#pos:<nowiki>This is a </nowiki>test|test}} returns 1.

#rpos:

The #rpos parser function was merged from the StringFunctions extension as of version 1.2.0

The #rpos function returns the last position of a given search term within the string. The syntax is:

 {{#rpos:string|search term}}

If the search term is found, the return value is a zero-based integer of its last position within the string.

If the search term is not found, the function returns -1.

When using this to search for the last delimiter, add +1 to the result to retrieve position after the last delimiter. This also works when the delimiter is not found, because "-1 + 1" is zero, which is the beginning of the given value.
* This function is case sensitive.
  • The maximum allowed length of the search term is limited through the $wgStringFunctionsLimitSearch global setting.
  • This function is safe with UTF-8 multibyte characters. Example: {{#rpos:Žmržlina|lina}} returns 4.
  • As with #len, <nowiki> and other tag extensions are treated as having a length of 1 for the purposes of character position. Example: {{#rpos:<nowiki>This is a </nowiki>test|test}} returns 1.

#sub:

The #sub parser function was merged from the StringFunctions extension as of version 1.2.0

The #sub function returns a substring from the given string. The syntax is:

{{#sub:string|start|length}}

The start parameter, if positive (or zero), specifies a zero-based index of the first character to be returned.

Example: {{#sub:Icecream|3}} returns cream.

{{#sub:Icecream|0|3}} returns Ice.

If the start parameter is negative, it specifies how many characters from the end should be returned.

Example: {{#sub:Icecream|-3}} returns eam.

The length parameter, if present and positive, specifies the maximum length of the returned string.

Example: {{#sub:Icecream|3|3}} returns cre.

If the length parameter is negative, it specifies how many characters will be omitted from the end of the string.

Example: {{#sub:Icecream|3|-3}} returns cr.

If the start parameter is negative, it specifies how many characters from the end should be returned. The length parameter, if present and positive, specifies the maximum length of the returned string from the starting point.

Example: {{#sub:Icecream|-3|2}} returns ea.

* If the length parameter is zero, it is not used for truncation at all.
    • Example: {{#sub:Icecream|3|0}} returns cream. {{#sub:Icecream|0|3}} returns Ice.
  • If start denotes a position beyond the truncation from the end by negative length parameter, an empty string will be returned.
    • Example: {{#sub:Icecream|3|-6}} returns an empty string.
  • This function is safe with UTF-8 multibyte characters. Example: {{#sub:Žmržlina|3}} returns žlina.
  • As with #len, <nowiki> and other tag extensions are treated as having a length of 1 for the purposes of character position. Example: {{#sub:<nowiki>This is a </nowiki>test|1}} returns test.

#replace:

The #replace parser function was merged from the StringFunctions extension as of version 1.2.0

The #replace function returns the given string with all occurrences of a search term replaced with a replacement term.

{{#replace:string|search term|replacement term}}

If the search term is unspecified or empty, a single space will be searched for.

If the replacement term is unspecified or empty, all occurrences of the search term will be removed from the string.

* This function is case-sensitive.
  • The maximum allowed length of the search term is limited through the $wgStringFunctionsLimitSearch global setting.
  • The maximum allowed length of the replacement term is limited through the $wgStringFunctionsLimitReplace global setting.
  • Even if the replacement term is a space, an empty string is used. This is a side-effect of the MediaWiki parser. To use a space as the replacement term, put it in nowiki tags.
    • Example: {{#replace:My_little_home_page|_|<nowiki> </nowiki>}} returns My little home page.
    • If this doesn't work, try {{#replace:My_little_home_page|_|<nowiki/> <nowiki/>}} with two self-closing tags.
    • Note that this is the only acceptable use of nowiki in the replacement term, as otherwise nowiki could be used to bypass $wgStringFunctionsLimitReplace, injecting an arbitrarily large number of characters into the output. For this reason, all occurrences of <nowiki> or any other tag extension within the replacement term are replaced with spaces.
  • This function is safe with UTF-8 multibyte characters. Example: {{#replace:Žmržlina|ž|z}} returns Žmrzlina.
  • If multiple items in a single text string need to be replaced, one could also consider Extension:ReplaceSet . It adds a parser function for a sequence of replacements.
Case-insensitive replace

Currently the syntax doesn't provide a switch to toggle case-sensitivity setting. But you may make use of magic words of formatting as a workaround. (e.g. {{lc:your_string_here}}) For example, if you want to remove the word "Category:" from the string regardless of its case, you may type:

{{#replace:{{lc:{{{1}}}}}|category:|}}

But the disadvantage is that the output will become all lower-case. If you want to keep the casing after replacement, you have to use multiple nesting levels (i.e. multiple replace calls) to achieve the same thing.

#explode:

The #explode parser function was merged from the StringFunctions extension as of version 1.2.0

The #explode function splits the given string into pieces and then returns one of the pieces. La sintaxis es:

{{#explode:string|delimiter|position|limit}}

The delimiter parameter specifies a string to be used to divide the string into pieces. This delimiter string is then not part of any piece, and when two delimiter strings are next to each other, they create an empty piece between them. If this parameter is not specified, a single space is used. The limit parameter is available in ParserFunctions only, not the standalone StringFunctions version, and allows you to limit the number of parts returned, with all remaining text included in the final part.

The position parameter specifies which piece is to be returned. Pieces are counted from 0. If this parameter is not specified, the first piece is used (piece with number 0). When a negative value is used as position, the pieces are counted from the end. In this case, piece number -1 means the last piece. Examples:

  • {{#explode:And if you tolerate this| |2}} returns you.
  • {{#explode:String/Functions/Code|/|-1}} returns Code.
  • {{#explode:Split%By%Percentage%Signs|%|2}} returns Percentage.
  • {{#explode:And if you tolerate this| |2|3}} returns you tolerate this.

The return value is the position-th piece. If there are fewer pieces than the position specifies, an empty string is returned.

* This function is case sensitive.
  • The maximum allowed length of the delimiter is limited through $wgStringFunctionsLimitSearch global setting.
  • This function is safe with UTF-8 multibyte characters. Example: {{#explode:Žmržlina|ž|1}} returns lina.

Limits

This module defines three global settings:

These are used to limit some parameters of some functions to ensure the functions operate in O(n) time complexity, and are therefore safe against DoS attacks.

$wgStringFunctionsLimitSearch

This setting is used by #pos, #rpos, #replace, and #explode. All these functions search for a substring in a larger string while they operate, which can run in O(n*m) and therefore make the software more vulnerable to DoS attacks. By setting this value to a specific small number, the time complexity is decreased to O(n).

This setting limits the maximum allowed length of the string being searched for.

The default value is 30 multibyte characters.

$wgStringFunctionsLimitReplace

This setting is used by #replace. This function replaces all occurrences of one string for another, which can be used to quickly generate very large amounts of data, and therefore makes the software more vulnerable to DoS attacks. This setting limits the maximum allowed length of the replacing string.

The default value is 30 multibyte characters.

General points

Substitución

Parser functions can be substituted by prefixing the hash character with subst::

{{subst:#ifexist: Help:Extension:ParserFunctions/es | [[Help:Extension:ParserFunctions/es]] | Help:Extension:ParserFunctions/es }} → the code [[Help:Extension:ParserFunctions/es]] will be inserted in the wikitext since the page Help:Extension:ParserFunctions/es exists.
Advertencia Advertencia: The results of substituted parser functions are undefined if the expressions contain unsubstituted volatile code such as variables or other parser functions. For consistent results, all the volatile code in the expression to be evaluated must be substituted. See Help:Substitution.

Substitution does not work within <ref></ref> , you can use {{subst:#tag:ref|}} for this purpose.

Redirecciones

Especially {{#time:…|now-…}} could be handy in redirects to pages including dates, but this does not work.

Escaping pipe characters in tables

Parser functions will mangle wikitable syntax and pipe characters (|), treating all the raw pipe characters as parameter dividers. To avoid this, most wikis used a template Template:! with its contents only a raw pipe character (|), since MW 1.24 a {{!}} magic word replaced this kludge. 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. It will then be interpreted as a table row or column separator. Alternatively, raw HTML table syntax can be used, although this is less intuitive and more error-prone.

You can also escape the pipe character for display as a plain, uninterpreted character using an HTML entity: &#124; .

Descripción Escribes Obtienes
Escaping pipe character as table row/column separator
{{!}}
|
Escaping pipe character as a plain character
&#124;
|

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 strings can be done after putting them in quotation marks.

{{#ifeq: foo           |           foo | equal | not equal }}equal
{{#ifeq: "foo          " | "          foo" | equal | not equal }}not equal

To prevent the trimming of then and else parts, see m:Template:If. Some people achieve this by using <nowiki > </nowiki> instead of spaces.

foo{{#if:|| bar }}foofoobarfoo
foo{{#if:||<nowiki /> bar <nowiki />}}foofoo bar foo

However, this method can be used to render a single whitespace character only, since the parser squeezes multiple whitespace characters in a row into one.

<span style="white-space: pre;">foo{{#if:||<nowiki></nowiki>      bar      <nowiki></nowiki>}}foo</span>
foo bar foo

In this example, the white-space: pre style is used to force the whitespace to be preserved by the browser, but even with it the spaces are not shown. This happens because the spaces are stripped by the software, before being sent to the browser.

It is possible to workaround this behavior replacing whitespaces with &#32; (breakable space) or &nbsp; (non-breakable space), since they are not modified by the software:

<span style="white-space: pre;">foo{{#if:||&#32;&#32;&#32;bar&#32;&#32;&#32;}}foo</span>foo bar foo
foo{{#if:||&nbsp;&nbsp;&nbsp;bar&nbsp;&nbsp;&nbsp;}}foofoo   bar   foo

Véase también

References

  1. Prior to r86805 in 2011 this was not the case.
  2. ExtParserFunctions.php at phabricator.wikimedia.org