Help:Extension:ParserFunctions/fr

L'extension ParserFunctions ajoute 11 fonctions supplémentaires au parseur, qui s'ajoutent aux fonctions des mots magiques présentes de base dans MediaWiki. Ces extensions se présentent ainsi :

#expr
La fonction #expr: évalue une expression mathématique, et retourne la valeur calculée.



Les opérateurs utilisables dans les calculs avec #expr: sont listés ci-contre, par ordre de précédence. Voir pour plus de détails sur un opérateur. La précision et le format du résultat retourné dépendent du système d'exploitation du serveur sur lequel est installé le Wiki, ainsi que du format de nombre du langage du site.

Dans un calcul, zéro équivaut à  et toute autre valeur différente de zéro (positive ou négative) équivaut à un   :



S'il n'y a aucune expression en entrée (ou une expression vide), la fonction retournera une chaîne vide. Toute expression invalide retournera le message d'erreur correspondant, que l'on peut capturer avec la fonction  :



L'ordre des opérandes d'additions et soustractions avant ou après un nombre est important, un signe mal placé peut ne pas être considéré comme une erreur mais comme l'indicateur que le nombre est positif ou négatif :



Note : si vous utilisez le résultat d'un mot magique dans une expression, vous devrez utiliser le format "raw" de ce résultat pour en retirer les séparateurs de milliers, et traduire les nombres. Par exemple : le mot magique donne, alors que nous voulons 0, que l'on peut obtenir par. Ceci est particulièrement important dans certaines langues où les nombres sont traduits, comme en Bengali où donne ৩০,০৬১.



Arrondir
Rounds arrondit le nombre à sa gauche en un multiple d'une puissance de 1/10, l'exposant étant égal à la valeur tronquée du nombre donné à sa droite.

Pour arrondir au supérieur ou à l'inférieur, utilisez respectivement les opérateurs unaires  et.

#if
La fonction #if: évalue une chaîne de test et détermine si elle est vide ou non. Une chaîne de test contenant seulement des espaces est considérée comme vide.





La fonction #if: teste d'abord si le premier paramètre n'est pas vide. S'il n'est pas vide, la fonction affiche le deuxième argument. Si le premier paramètre est vide ou ne contient que des caractères d'espacement (espaces, retour à la ligne, etc...), elle affiche le troisième argument.



La chaîne test est toujours interprétée comme du texte pur, ainsi les expressions mathématiques ne sont pas évaluées :



L'une ou l'autre des valeurs de retour peut être omise, ou les deux :



La fonction peut être imbriquée. Pour cela, imbriquez la fonction #if interne dans sa forme complète à la place du troisième paramètre de la fonction #if externe. Au moins 7 niveaux d'imbrication sont possibles, bien que cela puisse dépendre du wiki ou d'une limite de la mémoire.
 * Exemple:

Voir Help:Parser functions in templates pour plus d'exemples de cette fonction.

#ifeq
La fonction #ifeq: compare deux chaînes de caractères et détermine si elles sont identiques.



Si les deux chaînes sont des valeurs numériques valides, les chaînes sont comparées numériquement :



Sinon la comparaison s'effectue comme du texte ; cette comparaison est sensible à la casse :


 * →  (comparer à l'exemple similaire ci-dessus, sans les quotes)
 * →  (comparer à l'exemple similaire ci-dessus, avec  )
 * →  (comparer à l'exemple similaire ci-dessus, sans les quotes)
 * →  (comparer à l'exemple similaire ci-dessus, avec  )

Comme exemple pratique, étant donné un template existant  utilisé pour définir des tailles stadards courte et longue, défini ainsi :

il en résulte ce qui suit :


 * → 20
 * → 40
 * → 40

#iferror
La fonction #iferror: prend une chaîne en entrée et retourne un des deux résultats : la fonction s'évalue à  si la chaîne d'entrée contient un objet HTML avec , tel que généré par d'autres fonctions du parser comme  ,   et  , des erreurs de templates comme des boucles ou récursions, et d'autres erreurs "failsoft" du parser.



L'une ou l'autre des chaînes de retour, ou les deux, peuvent être omises. Si la chaîne  est omise, la chaîne   est retournée si elle n'est pas erronée. Si la chaîne  est aussi omise, une chaîne vide est retournée en erreur :


 * → &zwnj;
 * → &zwnj;
 * → &zwnj;
 * → &zwnj;
 * → &zwnj;
 * → &zwnj;

#ifexpr
La fonction #ifexpr: évalue une expression mathématique, et retourne une des deux chaînes selon la valeur booléenne du résultat.



L'  d'entrée est évaluée exactement comme pour   plus haut, avec les mêmes opérateurs disponibles. Le résultat est alors évalué comme expression booléenne.

Une expression vide en entrée s'évalue à  :



As mentioned above, zero evaluates to  and any nonzero value evaluates to , so this function is equivalent to one using   and   only:



except for an empty or wrong input expression (an error message is treated as an empty string; it is not equal to zero, so we get ).

comparing

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



#ifex
This function evaluates a mathematical expression and returns the calculated value.



The available operators are listed to the right, in order of precedence. See for more details of the function of each operator. The accuracy and format of the result returned will vary depending on the operating system of the server running the wiki, and the number format of the site language.

When evaluating using, zero evaluates to  and any nonzero value, positive or negative, evaluates to  :



An empty input expression returns an empty string. Invalid expressions return one of several error messages, which can be caught using the  function:



The order of addition and subtraction operands before or after a number is meaningful, and may be treated as a positive or negative value instead of as an operand with an erroneous input:



Note, if using the output of magic words, you must raw format them in order to remove commas, and translate the numerals. For example results in, where we want 0, which can be obtained using. This is especially important in some languages, where numerals are translated. For example, in Bengali, produces ৩০,০৬১.



Rounding
Rounds off the number on the left to a multiple of 1/10 raised to a power, with the exponent equal to the truncated value of the number given on the right.

To round up or down use unary  or   respectively.

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



The function evaluates to  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.



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



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

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

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

does not work with interwiki links.

ifexist limits
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  functions automatically return false, whether the target page exists or not, and the page is categorized into Category:. 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  (to select links to unexisting pages) or   (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.

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



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

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



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:



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

Examples:




 * 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  is returned if no   string matches the  :



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



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

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



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



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

Here cases 2, 3 and 4 all return ; cases 6 and 7 both return

Comparison behavior
As with, 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:





A  string may be empty:

Once a match is found, subsequent  are ignored:

Raw equal signs
"Case" strings cannot contain raw equals signs. To work around this, create a template = containing a single equals sign:.

Example:



For a simple real life example of the use of this function, check. Two complex examples can be found at and Template:BOTREQ.

Replacing #ifeq
can be used to reduce expansion depth.

For example: is equivalent to
 * (i.e. )
 * (i.e. )

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



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: In addition, the digraph  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.



The  can be in any format accepted by PHP's strtotime function. Both absolute (eg ) and relative (eg  ) times are accepted.

→ '''

→ '''

→ '''

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

→ '''

→  

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

→ '''

→ '''

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:



With MediaWiki r86805 - Code Review, a four-digit number is always interpreted as a year, never as hours and minutes:

→ '''

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):

→ ''' Input is treated as a time rather than a year+month code.

→ ''' 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:



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

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:

However, Venezuela is on a -4.5 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: To workaround this issue, simply convert the time into minutes or seconds, like this:

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

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



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



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



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


 * →  Strips one segment from the end of the string. See also.
 * →   Strips all 4 segments from the end of the string
 * →   Strips 5 segments from the end of the string (more than exist)
 * →   Returns last segment. See also.
 * →   Strips one segment from the end of the string, then returns the second segment and beyond
 * →   Start copying at the second last element; strip one segment from the end of the string

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:



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:



You can use #titleparts as a small "string parser & converter", but consider that it returns the first substring capitalized.




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


 * 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.

Certain characters that are illegal in a page title will cause #titleparts to not parse the string.
 * → . Does not produce the expected: {one



This function does not degrade gracefully if your input exceeds 255 characters. If the inputted string is 256 characters long or more, this function will simply toss the string back at you.

Strings parsing
An extension is available for additional string parsing, see Extension:StringFunctions.

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


 * → the code   will be inserted in the wikitext since the page exists.

Redirects
Especially   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 create the template    :! with its contents only a raw pipe character  or use the   magic word which is available since MW 1.24. 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:.

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.



For preventing trimming then- and else-parts, see m:Template:If. Some people use also &lt; nowiki &gt; &lt; /nowiki &gt; instead of spaces.


 * → foofoo
 * → foofoo

But this method only allows the rendering of one whitespace, since the parser reduce multiple spaces to a single one.


 * →  foofoo 

In this example, the  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  (breakable space) or   (non-breakable space), since they are not modified by the software:


 * →  foofoo 
 * → foofoo