本頁使用了標題或全文手工轉換

幫助:扩展:解析器函數

From mediawiki.org
Jump to navigation Jump to search
This page is a translated version of the page Help:Extension:ParserFunctions and the translation is 61% complete.

扩展:解析器函数 扩展提供11个額外的解析器函数以补充MediaWiki固有的“魔术字 ”。 (它有可能会配置到增加的解析器函数以支持运行:这些字符串函数已在其他文档页面 记载。) 所有的解析器函数由下列的表格提供。

{{#函数名: 参数1 | 参数2 | 参数3... }}

#expr

类型 运算符号
分组(括弧) ( )
数字 1234.5   e (2.718)   pi (3.142)
二进制运算符 e   一元 +,-
一元 not ceil trunc floor abs exp ln sin cos tan acos asin atan
二进制 ^
* / div mod
+ -
取整 round
逻辑 = != <> > < >= <=
and
or

这个函数计算并返回数学表达式的结果。 这个函数也通过mw.ext.ParserFunctions.expr函数中在扩展:Scribunto dex was 有效。

{{#expr: 表达式 }}

右表依优先级列出了支持的运算符,运算符的详细说明请见帮助:计算。运算结果的精度和格式受服务器操作系统及语言设置影响可能存在差异。

使用布尔代数时,0表示false,其他任何非0数值(无论正负)均表示true

{{#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

空表达式返回空值,错误的表达式返回错误信息,使用#iferror函数检查错误:

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

置于数字前或数字后的加减号是有意义的,会被视为正负号而不会报错:

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

注意:使用魔术字输出数值时,首先要将其格式化以去除逗号,获得纯数字。例如:{{NUMBEROFUSERS}}输出17,526,769,而期望的输出值是17526769,使用{{formatnum :{{NUMBEROFUSERS}}|R}}便可以实现。对于某些语言,格式化数字尤为重要。例如孟加拉语中,{{NUMBEROFUSERS}}的输出结果是৩০,০৬১。

{{#expr:{{NUMBEROFUSERS}}+100}} Expression error: Unrecognized punctuation character ",".
{{#expr:{{formatnum:{{NUMBEROFUSERS}}|R}}+100}}17526869
警告 警告: 运算符mod會對第二參數的某些值給出錯誤的结果:
{{#expr: 123 mod (2^64-1)}}Division by zero. (輸出一個空字符串;應該是123)
如果你想要进行基于日期时间的计算(如检测当前日期时间是否超过指定日期时间),首先用{{#time: xNU }}将日期时间转换为距1970年1月1日的秒数,再对秒数进行加减运算。

四舍五入

a round b是指将a四舍五入至(1/10)b的整数倍。

向上、向下取整分别使用ceilfloor

案例 结果 凑整方式
{{#expr: 1/3 round 5 }} 0.33333 最终的数字小于5,所以没有明显的取整发生 (0.333333… → 0.33333)
{{#expr: 1/6 round 5 }} 0.16667 最终的数字大于5,所以被向上取整 (0.166666… → 0.16667)
{{#expr: 8.99999/9 round 5 }} 1 同理,最后一位数因后一位而加1,进而引起了前面的进位 (0.999998… → 1.00000 → 1)
{{#expr: 1234.5678 round -2 }} 1200 舍入至最近的整百数,负值在小数点左边。
{{#expr: 1234.5678 round 2 }} 1234.57 舍入至最近的整1/100数,因为正值会舍入至小数点右边。
{{#expr: 1234.5678 round 2.3 }} 1234.57 舍入指数的小数点在舍入结果中不起作用
{{#expr: trunc 1234.5678 }} 1234 小数部分被全部舍弃(截断)
四舍五入至最近的整数
{{#expr: 1/3 round 0 }} 0 向下取整至0
{{#expr: 1/2 round 0 }} 1 向上取整至1
{{#expr: 3/4 round 0 }} 1 向上取整至1
{{#expr: -1/3 round 0 }} -0 向上取整至0
{{#expr: -1/2 round 0 }} -1 向下取整至-1
{{#expr: -3/4 round 0 }} -1 向下取整至-1
使用ceil和floor向上或向下取整
{{#expr: ceil(1/3) }} 1 向上取整至1
{{#expr: floor(1/3) }} 0 向下取整至0
{{#expr: ceil(-1/3) }} -0 向上取整至0
{{#expr: floor(-1/3) }} -1 向下取整至-1
{{#expr: ceil 1/3 }} 0.33333333333333 没有取整,因为1本来就是整数
警告 警告: 注意会被解析为(ceil 1)/3,而不是你想象中的ceil(1/3)

字符串

表达式函数只用于仅含有数字和运算符号的表达式,而字母字符串和其它符号不在此列。若需要比较字符串,可以用#ifeq替代。

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

#if

这个函数判断一个字符串是否为空。只包含空格的字符串被视为空字符串。

{{#if: 测试字符串 | 当测试字符串不是空值时的值 | 当测试字符串是空值(或只包括空格)时的值 }}
{{#if: 参数1 | 参数2 | 参数3 }}

这个函数首先判断参数1是否为空。如果参数1不为空,则输出参数2。如果参数1为空或只包含空白内容(空格、换行等),则输出参数3。

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


| yes | no}}
no

字符串内容会被处理为纯文本,因此数学表达式不会被计算:

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

最后一个参数(false)可以被忽略:

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

该函数可嵌套。为了做到这一点,嵌套内层的#if函数需要按规则完整填写所有参数以符合#if的参数形式。一般至多可嵌套7层,该数也可能为wiki自身限制和内存限制而有变动。

{{#if: 测试字符串 | 字符串非空时的值 | {{#if: 测试字符串 | 字符串非空时的值 | 字符串为空(或只有空格)的值 }} }}

你可以在#if条件句中以字符串变量代替测试字符串。在这里,你需要在变量名的后面加上| (分隔符)以正确引用字符串。 (因此如果参数没有值,则计算结果为一个空字符串而非"{{{1}}}")

{{#if:{{{1|}}}|你在变量1里面输入了文本|变量1里面没有文本 }}

在这里 幫助:模板中的解析器函数 获得更多关于解释器函数中变量的相关例子。

#ifeq

这个函数判断两个輸入字符串是否相同,並根據結果輸出兩個字符串的其中一個。 如果需要更多的比較和輸出字符串,請考慮使用#switch

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

如果两个字符串均为数字,则函数会进行数值的比较:

{{#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

否则函数会进行文本的比较(大小写敏感):

{{#ifeq: foo | bar | equal | not equal}}not equal
{{#ifeq: foo | Foo | equal | not equal}}not equal
{{#ifeq: "01" | "1" | equal | not equal}}not equal  (对比上面没有引号的例子)
{{#ifeq: 10^3 | 1000 | equal | not equal}}not equal  (对比上面带有#expr的例子,會先回傳一個有效的整數)

作为例子,考虑一个已经存在着的模板 Template:Timer,该模板利用解析器来選擇兩個標準時間,short和long。 它以参数作为第一个输入来比较字符串“short”–这没有约定顺序,但是如果参数在第一个则更容易理解。 模板代码定义为:

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

会产生如下结果:

{{timer|short}}20
{{timer|20}}40
{{timer}}40
警告 警告: 在数值比较结果上,#ifexpr不总是和解释器#ifeq#switch保持一致。 后面两种比较相对于#ifexpr而言更加精确,因而未必返回相同结果。

考虑比较下面两个仅有最后一个数码不同的数:

{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}not equal
{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}not equal

因为用于#ifeq#switch的PHP用整数类型比较两个数,它会正确返回预期结果。 然而用#ifexpr比较相同的两个数时:

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

对于不同的数字,结果实际上是不正确的。

造成#ifexpr出错行为的原因是MediaWiki将两个数依字面表达理解成了浮点数,而对于像这样的大数,转换为浮点数由于精度误差会存储为一样的数值,导致出错。


警告 警告: 如果比较参数使用了解释器函数,任何的解释器标记和其它的解释器函数都一定会被一个临时生成的独一无二的标识码 所替代。这会影响如下列的比较:
{{#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
如果被比较字符串从所使用的模板 到模板内使用的参数和标记都是相同的,那么这种情况下会返回真值,但如果所使用模板名不同,即便内容是完全一致的,判断也会返回假值。


警告 警告: 随网站配置的变化,含有页面名字的魔术字 的字符串的字面比较可能会发生错误。 比如说,{{FULLPAGENAME}}这一魔术字随wiki的变化,可能在返回时使开头字母变成大写,也会用下划线替代空格。

为了解决这个问题,将这个魔术字应用到两个参数上:

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


#iferror

这个函数以一个字符串为输入,然后在两条预选结果中取其一而返回。函数认定为true当且仅当作为输入参数的字符串在解释时返回的结果中含有一个class="error"的HTML对象,而其中可用来认定结果的包括其他的解释器函数(比如#expr#time#rel2abs)的错误,模板错误(比如模板循环和模板递归),还有一些其它的解释器“软错误”。

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

待返回字符串参数可以省略。若省略"correct"(正确)字符串参数,则在"test string"(测试字符串)不出错的情况下函数将返回被测字符串本身。若省略"error"(错误)字符串参数,则函数将在被测字符串出错时返回空字符串:

{{#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

此函数会判断数学表达式并根据其布尔值结果返回对应的字符串:

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

这里"expression"输入串将原封不动的作为上面#expr的参数进行调用,且表达式运算符是通用的,返回值也将作为布尔表达式进行处理。

输入表达式为空时将视为false

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

如上面所提,0将视为false,非零值将视为true,因此这个函数与下面的仅用#ifeq#expr的表述等价:

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

除了下面这种情况:所输入表达式为空或者是一个错误表达式(空串会返回一条错误信息,而它不等于0,所以在后者我们会得到"value if true")。

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

相对的

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

两个待选返回值都不是必填的。当表达式判断对应的分支返回值被省略时,函数不会给出输出:

{{#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 }}

Boolean operators of equality or inequality operators are supported.

{{#ifexpr: 0 = 0 or 1 = 0 | yes}}yes
{{#ifexpr: 0 = 0 and 1 = 0 | | no}}no

#ifexist

这个函数将一组字符串作为输入,并翻译成页面标题,然后根据在本地wiki上是否存在该页面而返回对应的值。

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

只要页面存在就会判定为true(真值),即便那个页面看上去是空白的(比如像是分类链接或者是魔术字 解释页之类的却不包含任何可视内容的页面),或者是重定向页 ,或者它就是空白页。当且仅当页面是红链时判定为false(假值),包括那些曾经存在却被删除的页面。

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

函数在系统消息 对应模块被安装时认定为true,对特殊页面 的判定则取决于本地软件自身。

{{#ifexist: Special:Watchlist | exists | doesn't exist }}exists
{{#ifexist: Special:CheckUser | exists | doesn't exist }}exists (因为Checkuser 扩展已经安装于此wiki)
{{#ifexist: MediaWiki:Copyright | exists | doesn't exist }}exists (因为MediaWiki:Copyright已被自定义)

如果一个页面使用了#ifexist:来检查目标页面,则这个检查页面将出现在被检查页面的Special:WhatLinksHere里。所以如果本页面(Help:Extension:ParserFunctions/zh)使用了代码 {{#ifexist:Foo}},那么Special:WhatLinksHere/Foo将列出Help:Extension:ParserFunctions/zh。

若wiki有其在使用的对应的共享媒体库,#ifexist:就可用于检查一个文件是否在媒体库中,而不仅仅只是在wiki本体上检查:

{{#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

如果文件有一个已创建的对应的本地描述页面,上面的结果将全部是exists

#ifexist:不会对跨wiki链接起作用。

ifexist 限制

#ifexist:被视为“高开销(expensive)解析器函数”,每个页面调用这类函数的次数(包括包含于嵌入式模板的函数)存在一个限制。当达到该限制时,对于多出该限制的#ifexist:函数,无论其目标页面是否存在,函数只会自动返回错误值false,且该页面会被分类到Category:Pages with too many expensive parser function calls中。追踪分类 可能因您的wiki内容的语言而异。

在某些案例中,在css中,利用选择器a.new(以选出链接到不存在的页面的链接)或者是a:not(.new)(以选出已存在页面的链接),是可以达到模仿ifexist的效果的。另外,控制$wgExpensiveParserFunctionLimit 可以调整对高开销解析器函数数量的限制,如果有需要,也可以增加页面LocalSettings.php中的限制值。

ifexisit和需要的页面

一个不存在的页面被#ifexist检测后会被计数在待创建页面中。 请参阅任务T14019了解原因,并查看w:Template:Linkless exists以了解解决方法。

#rel2abs

这个函数将文件的相对路径转换为绝对路径。

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

在输入项path中,可以使用以下类型的句法:

  • . → 本级路径
  • .. → 回到上一级
  • /foo → 向下一级进入子目录/foo

base path没有指定,将默认的填入函数所在页面的绝对路径:

{{#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

形如/././的不合理的句法将被忽略。 连用至多两个句点(如:..)是可以的,语句会被正确的分割成可成功执行的情况:

{{#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

See also: w:Help:Switch parser function

该函数将一个输入值同若干个测试样例(test cases)做比较,如果找到匹配,返回有关联的字符串。

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

例如:

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

含有部分嵌入包含标记的#switch会影响到能让不熟悉模板代码的编辑者查看和编辑可配置元素的配置文件。

默认

如果comparison string不能与任何case匹配,则返回default result,即默认结果:

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

在这种语法中,默认返回值必须是函数的最后一个参数,而且不能包含原始等号(不帶{{}}的等號)。 否则,就会解析为样例比较,无匹配的样例时不显示文本。 这是因为默认值没有定义(是空的)。 如果有样例匹配,则返回关联的字符串。

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

你也可以将case字符串设为#default从而清楚地声明默认值。

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

这种方式声明的默认结果可以放在函数的任何地方:

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

如果"default"参数被省略,且没有找到匹配,则不返回结果:

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

分组结果

该函数允许存在“fall through”现象,多个"case"字符串返回相同的"result"字符串,从而减少重复。

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

在本例中,第二、三、四个分支都会返回"result234",第六和第七个分支都会返回"result67"。 上述案例中,最后一个参数中的“#default = ”可以省略。

带有参数使用

该函数允许将参数用作测试字符串。 在本例中,不必将管道符放在参数名称后面,因为你不太可能需要选择字符串“{{{parameter name}}}”作为样例。 ((如果没有管道符,且参数不存在或没有值,则参数就会显示为这样。) 参见幫助:模板中的解析器函数 。)

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

上面的例子中,如果{{{1}}}等于foo,函数返回Foo。 如果等于baz,函数返回Baz。 如果参数是空的或者不存在,函数返回Bar

上面的这些中,也可以将样例组合起来以返回单个结果。

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

如果{{{1}}}等于foozooroo,函数返回Foo。 如果等于baz,函数返回Baz。 如果参数是空的或者不存在,函数返回Bar

而且,如果你希望在测试参数不能匹配任何样例时不返回任何内容,可以省略默认结果。

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

在本例中,如果{{{1}}}存在且等于foobar,则分别返回FooBar,否则不返回任何内容。

这样做相当于将默认值声明为空。

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

如果由于某些原因需要将样例设置为{{{parameter name}}},则函数在参数不存在或没有值的情况下返回该样例的结果。 参数需要存在且拥有不同于字符串“{{{parameter name}}}”的值以返回函数的默认结果。

(若{{{1}}}不存在或者是空的):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Foo
(若{{{1}}}的值为test):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Bar
(若{{{1}}}的值为“{{{1}}}”):
{{#switch: {{{1}}} | {{{1}}} = Foo | baz = Baz | Bar }} Foo


在这样的例子中,你需要给参数添加管道符({{{1|}}})。

比较行为

如同#ifeq那样,若被比较串和测试条件串都是数字串的,那么将之按照数字进行比较;反之若存在一个非纯数字串,都会按照字符串比较规则进行:

{{#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

case字符串可以是空的:

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

只要找到一个匹配,后面的case都会忽略:

{{#switch: b | f = Foo | b = Bar | b = Baz | }}Bar
警告 警告: #switch#ifeq的数值比较结果未必一致(参见上面#ifeq部分):
{{#switch: 12345678901234567 | 12345678901234568 = A | B}} → B
{{#ifexpr: 12345678901234567 = 12345678901234568 | A | B}} → A


原始等号

“case”字符串不能包含原始等号。如果需要在比较串中加入等号,可以使用仅包含一个等号的模板{{=}}来代替=,或者是用HTML标识码&#61;来代替。

例如:

{{#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
为助您理解,您可以检查模板:NBA球队代表色模板:扩展 w:Template:BOTREQ是两个使用该函数的复杂例子。

替换#ifeq

#switch可以用于减少扩展深度

例如:

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

等效于

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

也就是线性的深度迭代判断:

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

但同时,用switch代替嵌套的IF语句有可能会使语句变得更为复杂,甚至弄巧成拙,例如下面的这个例子,IF语句构成了一棵对称的决策树,相应对称的部分已经用缩进和注释标齐:

{{#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

该解析器函数接收一个日期或者时间(在Gregorian历),并根据给定的语法将其格式化。可以指定日期/时间对象,默认则为魔术字Special:MyLanguage/Help:Magic words#Date and time的当前值——也就是说,页面最后被渲染为HTML时的时间。

{{#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 }}

右表列举了支持的格式化代码。任何不被识别的格式化字符串都不会被修改,这同样适用于空白字符(系统不使用空白字符来解释代码)。格式化字符串内有两种方法来转义字符:

  1. 反斜杠后跟随一个格式化字符串会被解释为单个原始的字符
  2. 用英文双引号括起来的字符视为原始字符,引号将被移除。

此外,xx会被解释为单个原始的x。

As the list of formatting codes continues to evolve (with the support of new calendars, or of new date fields computed and formatted differently), you should escape all literal characters (not just ASCII letters currently used by formatting codes) that need to be passed through unaltered.

Unfortunately, for now, the ASCII single quote is still not recognized as a simple alternative for marking literal text to the currently supported ASCII double quotes (for example, double quotes are mandatory for in other uses like the delimitation of string values in JSON, C, C++...) and backslashes (which have to be escaped as well in string constants used by many languages, including JSON, C, C++, PHP, JavaScript, Lua). So you still cannot embed any literal double quote without escaping it with a backslash (or you can use other curly, angular or square quotation marks instead).

{{#time: Y-m-d }}2021-09-22
{{#time: [[Y]] m d }}2021 09 22
{{#time: [[Y (year)]] }}2021 (21UTCpmWed, 22 Sep 2021 21:49:16 +0000)
{{#time: [[Y "(year)"]] }}2021 (year)
{{#time: i's" }}49'16"

date/time object可以是任何PHP strtotime() 函数接受的格式。绝对(例如20 December 2000)和相对(例如+20 hours)时间都可接受。

{{#time: r|now}}Wed, 22 Sep 2021 21:49:16 +0000
{{#time: r|+2 hours}}Wed, 22 Sep 2021 23:49:16 +0000
{{#time: r|now + 2 hours}}Wed, 22 Sep 2021 23:49:16 +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.

ISO 639-3(?)中的language code允许字符串显示为指定语言。

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

local参数指定date/time object是否指本地市区或者UTC时间。

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).

请注意,如果$wgLocaltimezone设为UTC,则当local设为truefalse时输出无区别。

参考下面的详细示例:

{{#time: Y F d H:i:s|now|it|0}}2021 settembre 22 21:49:16
{{#time: Y F d H:i:s|now|it|1}}2021 settembre 22 21:49:16
{{#time: Y F d H:i:s|+2 hours||0}}2021 9月 22 23:49:16
{{#time: Y F d H:i:s|+2 hours||1}}2021 9月 22 23:49:16
{{#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

如果你已经计算了Unix时间戳,你可以通过添加@符号前缀来在日期计算中使用。

{{#time: U | now }}1632347356
{{#time: r | @1632347356 }}Wed, 22 Sep 2021 21:49:16 +0000
警告 警告: 若不在數字格式的時間戳值的前面包含@前綴,結果通常會出錯或是未預期的數值:
{{#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 (正確)
{{#time: r | 999 }}Error: Invalid time. (不支援的年份格式)
{{#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 (正確)
{{#time: r | 1000 }}Mon, 22 Sep 1000 00:00:00 +0000 (被解讀為某年的目前月分和日期)
{{#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 (正確)
{{#time: r | 9999 }}Wed, 22 Sep 9999 00:00:00 +0000 (被解讀為某年的目前月分和日期)
{{#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 (正確)
{{#time: r | 10000 }}Error: Invalid time. (不支援的年分格式)


警告 警告: 可接受的范围为0111年1月1日(1 January 0111)到9999年12月31日(31 December 9999)。对于年份100到110,输出不连贯,Y和闰年类似于年份100-110,而r、D、I和U可能会将这些年份解释为2000-2010。
{{#time: d F Y | 29 Feb 0100 }}01 3月 0100
(正確,沒有閏年),但是
{{#time: r | 29 Feb 0100 }}Mon, 01 Mar 0100 00:00:00 +0000 (錯誤,100被解讀為2000,但那是閏年)
{{#time: d F Y | 15 April 10000 }}Error: Invalid time.
{{#time: r | 10000-4-15 }}Sat, 15 Apr 2000 10:00:00 +0000

年份数字0-99解释为2000-2069和1970-1999,除非添加前缀0以写成四位数格式:

{{#time: d F Y | 1 Jan 6 }}01 1月 2006
{{#time: d F Y | 1 Jan 06 }}01 1月 2006
{{#time: d F Y | 1 Jan 006 }}01 1月 2006
{{#time: d F Y | 1 Jan 0006 }}01 1月 0006 (4-digit format)
年份100-110和1753之后的年份支持工作日,对于年份111-1752,r的输出显示“Unknown”,l输出“<>”,结果,这些年份不支持r输出。


可以指定完整的或部分绝对的日期;函数会使用“当前”值“填充”日期中未被指定的部分。

{{#time: Y | January 1 }}2021
警告 警告: “填充”功能并不连贯,有些部分会使用当前值填充,其他的则不会:
{{#time: Y m d H:i:s | June }}2021 06 22 00:00:00 给予这一天的开始,而不是当前月份中的日期和当前年份。
{{#time: Y m d H:i:s | 2003 }}2003 09 22 00:00:00 给予这一天的开始,而不是这一年的当前日期。

填充日期有特例:

{{#time: Y m d H:i:s | June 2003 }}2003 06 01 00:00:00 给予这一天的开始和这个月的开始。


4位數字總是被解讀為年分,而不是小時和分鐘:[1]

{{#time: Y m d H:i:s | 1959 }}1959 09 22 00:00:00

6位數字儘量被解讀為小時、分鐘、秒,不然會被解讀為錯誤(而不是年份和月份):

{{#time: Y m d H:i:s | 195909 }}2021 09 22 19:59:09 輸入被視為時間而不是年+月代碼。
{{#time: Y m d H:i:s | 196009 }}Error: Invalid time. 雖然19:60:09不是有效時間,但196009不被解讀為1960年9月。

該函數執行一定數量的日期算數:

{{#time: d F Y | January 0 2008 }}31 12月 2007
{{#time: d F | January 32 }}Error: Invalid time.
{{#time: d F | February 29 2008 }}29 2月
{{#time: d F | February 29 2007 }}01 3月
{{#time:Y-F|now -1 months}}2021-8月

#time調用的格式字符串的總長度限制為6000個字符[2]

时区问题

#time解析器函数有个bug(尤其是PHP DateTime),不允许传入非整数的相对时区偏移。这个问题不适用于使用基于小时的时区,例如EDT。例如:

  • {{#time:g:i A | -4 hours }} → 5:49 PM

但是,印度(India)是UTC +5.5个小时的时间偏移,因此使用时区不会正常地计算相对时区偏移。因此:

  • {{#time:g:i A | +5.5 hours }} → 9:49 PM

要解决这个问题,可将时间简单转换为分钟或者秒,像这样:

  • {{#time:g:i A | +330 minutes }} → 3:19 AM
  • {{#time:g:i A | +19800 seconds }} → 3:19 AM

(Tim Starling,该函数的开发者,提供了该解决方案的准确语法。)

#timel

该函数等价于{{#time: ... }},其中local参数设置为true,因此总是使用wiki的本地时间($wgLocaltimezone 中设置的)。

该函数的语法为:

{{#timel: format string }}
{{#timel: format string | date/time object }}
{{#timel: format string | date/time object | language code }}
请注意,如果变量$wgLocaltimezone设为UTC,则当local设为truefalse时输出无区别。
使用#time和#timel解析器函数的示例,其中服务器处于非UTC时区

例如,参考以下示例:

{{#time:c|now|it}}2021-09-22T21:49:16+00:00
{{#time:c|now|it|0}}2021-09-22T21:49:16+00:00
{{#time:c|now|it|1}}2021-09-22T21:49:16+00:00
{{#timel:c|now|it}}2021-09-22T21:49:16+00:00
https://no.wikipedia.org/wiki/Maldiskusjon:Sommertid的警告範例
警告 警告: 注意对于time和timel,U会都返回自1970-01-01 00:00:00 UTC(即GMT)的秒数,无论时区是否为UTC。
U Unix时间。自1970年1月1日 00:00:00(GMT)以来的秒数。
Z 时区偏移(秒)。
{{#time: U}}1632347356
{{#timel: U}}1632347356
{{#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. 参见{{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. 参见{{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
警告 警告:

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


警告 警告:

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.


警告 警告:

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


警告 警告: 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.

  1. 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.
  1. To determine whether a MediaWiki server enables these functions, check the list of supported Extended parser functions in Special:Version.
  1. 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.
  • 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.
  • 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.

#count

The #count parser function was added to the StringFunctions extension as of version 1.2.0.

The #count function returns the number of times a given substring appears within the provided text.

{{#count:string|substring}}

#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.
  • 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. The syntax is:

{{#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.

#urldecode

#urldecode converts the escape characters from an 'URL encoded' string string back to readable text. The syntax is:

{{#urldecode:value}}

Notes:

  • This function works by directly exposing PHP's urldecode() function.
  • A character-code-reference can be found at www.w3schools.com.
  • The opposite, urlencode, has been integrated into MediaWiki as of version 1.18; for examples, see Help:Magic Words .
  • urldecode was merged from Stringfunctions in 2010, by commit 1b75afd18d3695bdb6ffbfccd0e4aec064785363

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.

一般帮助

替代

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

{{subst:#ifexist: Help:Extension:ParserFunctions/zh | [[Help:Extension:ParserFunctions/zh]] | Help:Extension:ParserFunctions/zh }}the code [[Help:Extension:ParserFunctions/zh]] will be inserted in the wikitext since the page Help:Extension:ParserFunctions/zh exists.
警告 警告:

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.

重定向

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

在表格中逸出的管道符

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; .

说明 您输入的 您输出的
Escaping pipe character as table row/column separator
{{!}}
|
Escaping pipe character as a plain character
&#124;
|

剥离空格

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/>      bar      <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

参见

参考资料

  1. 在2011年r86805之前,情況並非如此。
  2. phabricator.wikimedia.org的ParserFunctions.php