Help:扩展:ParserFunctions

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The ParserFunctions extension provides eleven additional parser functions to supplement the "magic words", which are already present in MediaWiki. (It may be configured to provide additional parser functions for string handling; these string functions are documented elsewhere.) All the parser functions provided by this extension take the form:

{{#函数名: 参数1 | 参数2 | 参数3... }}

#expr

类型 操作者
分组(括弧) ( )
数字 1234.5   e (2.718)   pi (3.142)
二进制操作者 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。

{{#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Help:Calculation。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 foo 2 }}Expression error: Unrecognized word "foo".

置于数字前的加减号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:使用魔术字输出的数值时,首先要将其格式化以去除逗号,获得纯数字。例如:{{NUMBEROFUSERS}}输出3,173,212,而期望的输出值是3173212,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}}3173312
Warning Warning: The operator mod gives wrong results for some values of the second argument:
{{#expr: 123 mod (2^64-1)}}Division by zero. (produces an empty string; should be 123)
如若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1970.1.1的秒数,再对秒数进行加减运算。

凑整

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 ceil or floor respectively.

案例 结果 Method of rounding
{{#expr: 1/3 round 5 }} 0.33333 Final digit is < 5, so no apparent rounding occurs
{{#expr: 1/6 round 5 }} 0.16667 Final digit is >= 5, so it is rounded up
{{#expr: 8.99999/9 round 5 }} 1 Again, the result is rounded up on the last digit, which results in additional rounding
{{#expr: 1234.5678 round -2 }} 1200 Rounded to nearest 100 because negative values round to the left of the decimal point
{{#expr: 1234.5678 round 2 }} 1234.57 Rounded to nearest 100th since positive values round to the right of the decimal point
{{#expr: 1234.5678 round 2.3 }} 1234.57 Decimals in the rounding index make no difference in the rounded result
{{#expr: trunc 1234.5678 }} 1234 Decimal portion truncated (chopped off)
Rounding to the nearest integer
{{#expr: 1/3 round 0 }} 0 Down to the nearest integer, which is zero
{{#expr: 1/2 round 0 }} 1 Up to the nearest integer, which is one
{{#expr: 3/4 round 0 }} 1 Up to the nearest integer, which is one
{{#expr: -1/3 round 0 }} 0 Up to the nearest integer, which is zero
{{#expr: -1/2 round 0 }} -1 Down to the nearest integer, which is negative one
{{#expr: -3/4 round 0 }} -1 Down to the nearest integer, which is negative one
Rounding up or down with ceil and floor
{{#expr: ceil(1/3) }} 1 Up to the next larger integer, which is one
{{#expr: floor(1/3) }} 0 Down to the next smaller integer, which is zero
{{#expr: ceil(-1/3) }} 0 Up to the next larger integer, which is zero
{{#expr: floor(-1/3) }} -1 Down to the next smaller integer, which is negative one
{{#expr: ceil 1/3 }} 0.33333333333333 Not rounded since 1 already is an integer
Warning Warning: Interpreted as (ceil 1)/3, not ceil(1/3) as you might expect

#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: 字符串 | value if test string is not empty | value if test string is empty (or only white space) }}
{{#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

The last parameter (false) may be omitted:

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

The function may be nested. To do so, nest the inner #if function in its full form in place of a parameter of the enclosing #if function. A depth of at least seven levels of nesting is possible, although that may depend on the wiki or a memory limit.

  • Example: {{#if: test string | value if test string is not empty | {{#if: test string | value if test string is not empty | value if test string is empty (or only white space) }} }}

You can also use a parameter as the test string in your #if statement. You need to ensure you add the | (pipe symbol) after the name of the variable.

  • Example {{#if:{{{1|}}}|You entered text in variable 1|There is no text in variable 1}}

See Help:Parser functions in templates for more examples of this parser function.

#ifeq

这个函数判断两个字符串是否相同。

{{#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)

As a practical example, given an existing template Template:Size used to set standard short and long sizes, defined as:

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

the following ensue:

{{size|short}}20
{{size|20}}40
{{size}}40
Warning Warning: Numerical comparisons with #ifeq and #switch are not equivalent to comparisons with #expr:
{{#ifeq: 12345678901234567 | 12345678901234568 | equal | not equal}}not equal
{{#switch: 12345678901234567 | 12345678901234568 = equal | not equal}}not equal

because PHP compares two numbers of type integer, whereas:

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

because MediaWiki converts literal numbers in expressions to type float, which, for large integers like these, involves rounding.

Warning Warning: Tags and parser functions inside parser tags (such as <nowiki>) are temporarily replaced by a unique code. This affects comparisons:
{{#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

If the strings to be compared are given as equal calls to the same template containing such tags, then the condition is true, but in the case of two templates with identical content containing such tags it is false.

Warning Warning:

Be careful when comparing against the current page title using the page name magic words. These magic words convert special characters into numeric HTML entities. This may result in misleading results. For example, if you are on a page titled "L'Aquila"...

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

NOTE: The above is actually wrong: Due to improvements, it will now return "equal". However, this can be important in some other cases; for example, {{FULLPAGENAME}}, depending on wiki, may capitalize the first letter, and will replace all underscores with spaces.

To work around this, apply the magic word to both parameters:

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

#iferror

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

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

One or both of the return strings can be omitted. If the correct string is omitted, the test string is returned if it is not erroneous. If the error string is also omitted, an empty string is returned on an 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

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 }}

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

An empty input expression evaluates to false:

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

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

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

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 value if true).

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

比较

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

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

{{#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

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 }}

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/zh | exists | doesn't exist }}exists
{{#ifexist: XXHelp:Extension:ParserFunctions/zhXX | 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 (因为用户查核拓展已经安装于此wiki)
{{#ifexist: MediaWiki:Copyright | exists | doesn't exist }}exists (因为MediaWiki:Copyright已经自定义)

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/zh), Special:WhatLinksHere/Foo will list Help:Extension:ParserFunctions/zh.

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.

ifexist 限制

#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 $wgExpensiveParserFunctionLimitManual:$wgExpensiveParserFunctionLimit, one can also increase the limit in LocalSettings.php if needed.

#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
}}

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

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

Default

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.

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

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 }}

Grouping results

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

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
Warning Warning: Numerical comparisons with #switch and #ifeq are not equivalent with comparisons in expressions (see also above):
{{#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: =.

例:

{{#switch: 1=2
 | 1=2 = raw
 | 1<nowiki>=</nowiki>2 = nowiki
 | 1&#61;2 = html
 | 1{{=}}2 = template
 | default
}}html

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

Replacing #ifeq

#switch can be used to reduce expansion depth.

例如:

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

is equivalent to

  • {{#ifeq:{{{1}}}|condition1 |branch1 |{{#ifeq:{{{1}}}|condition2 |branch2 |{{#ifeq:{{{1}}}|condition3 |branch3 |branch4}}}}}}
(i.e. {{#ifeq:{{{1}}}|condition1 |<!--then-->branch1 |<!--else-->{{#ifeq:{{{1}}}|condition2 |<!--then-->branch2 |<!--else-->{{#ifeq:{{{1}}}|condition3 |<!--then-->branch3 |<!--else-->branch4}}}}}})

#time

代码 描述 Current output
(Purge this page's cache to update)
Y 4位数年。 2015
y 2位数年。 15
L 如果是闰年则为1,否则为0。 0
o ¹ ISO-8601 year of the specified week. ² 2015 ³

¹ Requires PHP 5.1.0 and newer and rev:45208.
² This has the same value as Y, except that if the ISO week number (W) belongs to the previous or next year, that year is used instead.
³ Will output literal o if ¹ not fulfilled.

n Month index, not zero-padded. 9
m Month index, zero-padded. 09
M An abbreviation of the month name, in the site language. 9月
F The full month name in the site language. 9月
xg Output the full month name in the genitive form for site languages that distinguish between genitive and nominative forms. This option is useful for many Slavic languages like Polish, Russian, Belarusian, Czech, Slovak, Slovene, Ukrainian, etc. 波兰语:

(主格)

{{#time:d F Y|20 June 2010|pl}} → 20 czerwiec 2010

(属格)

{{#time:d xg Y|20 June 2010|pl}} → 20 czerwca 2010

W ISO 8601周数,零填充。 36
j 月内一日,非零填充。 2
d 月内一日,零填充。 02
z Day of the year (January 1 = 0).
Note Note: To get the ISO day of the year add 1.
244
D An abbreviation for the day of the week. Rarely internationalized.
l The full weekday name. Rarely internationalized. 星期三
N ISO 8601 day of the week (Monday = 1, Sunday = 7). 3
w Number of the day of the week (Sunday = 0, Saturday = 6). 3
小时
a "am" during the morning (00:00:00 → 11:59:59), "pm" otherwise (12:00:00 → 23:59:59). pm
A Uppercase version of a above. PM
g Hour in 12-hour format, not zero-padded. 5
h Hour in 12-hour format, zero-padded. 05
G Hour in 24-hour format, not zero-padded. 17
H Hour in 24-hour format, zero-padded. 17
Minutes and seconds
i Minutes past the hour, zero-padded. 40
s Seconds past the minute, zero-padded. 11
U Seconds since January 1 1970 00:00:00 GMT. 1441215611
Timezone (as of 1.22wmf2)
e Timezone identifier. UTC
I Whether or not the date is in daylight savings time. 0
O Difference to Greenwich time (GMT) +0000
P Difference to Greenwich time (GMT), with colon +00:00
T Timezone abbreviation. UTC
Z Timezone offset in seconds. 0
杂项
t Number of days in the current month. 30
c ISO 8601 formatted date, equivalent to Y-m-d"T"H:i:s+00:00. 2015-09-02T17:40:11+00:00
r RFC 5322 formatted date, equivalent to D, j M Y H:i:s +0000, with weekday name and month name not internationalized. Wed, 02 Sep 2015 17:40:11 +0000
非公历(格里历)历法
伊斯兰教历法
xmj 月内一日。 18
xmF 月的全名。 Dhu al-Qi'dah
xmn 月索引。 11
xmY 全年。 1436
伊朗历法(Jalaly)
xij 月内一日。 11
xiF 月的全名。 Shahrivar
xin 月索引。 6
xiY 全年。 1394
xiy 2位数年。 94
希伯来历法
xjj 月内一日。 18
xjF 月的全名。 Elul
xjt 月内日数。 29
xjx Genitive form of the month name. Elul
xjn 月数。 12
xjY 全年。 5775
泰历
xkY Full year in Thai solar calendar.
Note 注意: For years before 1941 the dates in Jan-Mar range are not calculated properly.
2558
民国纪年
xoY 全年。 104
日本历法
xtY 全年。 平成27
标记
xn Format the next numeric code as a raw ASCII number. In the Hindi language, {{#time:H, xnH}} produces ०६, 06.
xN Like xn, but as a toggled flag, which endures until the end of the string or until the next appearance of xN in the string.
xr Format the next number as a roman numeral. Only works for numbers up to 10,000
(upto 3,000 in pre MediaWiki 1.20).
{{#time:xrY}} → MMXV
xh Format the next number as a Hebrew numeral. {{#time:xhY}} → ב'ט"ו

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 }}

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 }}2015-09-02
{{#time: [[Y]] m d }}2015 09 02
{{#time: [[Y (year)]] }}2015 (15UTCpmWed, 02 Sep 2015 17:40:11 +0000)
{{#time: [[Y "(year)"]] }}2015 (year)
{{#time: i's" }}40'11"

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}}Wed, 02 Sep 2015 17:40:11 +0000
{{#time: r|+2 hours}}Wed, 02 Sep 2015 19:40:11 +0000
{{#time: r|now + 2 hours}}Wed, 02 Sep 2015 19:40:11 +0000

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}}середа
{{#time:d xg Y|20 June 2010|pl}}20 czerwca 2010

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

{{#time: U | now }}1441215611
{{#time: r|@1441215611}}Wed, 02 Sep 2015 17:40:11 +0000

Warning Warning: 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 3月 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 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)

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 }}2015
Warning Warning: 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 }}2015 06 02 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 09 02 00:00:00 Gives the start of the day, but the current day of the year.

With MediaWiki r86805 - Code Review, a four-digit number is always interpreted as a year, never as hours and minutes:
{{#time: Y m d H:i:s | 1959 }}1959 09 02 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 }}2015 09 02 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 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}}2015-8月

The total length of the format strings of the calls of #time is limited to 6000 characters [1].

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 }} ==> 1:40 PM

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:

  • {{#time:g:i A | -4.5 hours }} ==> 2:40 AM

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

  • {{#time:g:i A | -270 minutes }} ==> 1:10 PM
  • {{#time:g:i A | -16200 seconds }} ==> 1:10 PM

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

#timel

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

{{#time: Y-m-d }}2015-09-02
{{#timel: Y-m-d }}2015-09-02
{{#time: Y F d H:i:s}}2015 9月 02 17:40:11
{{#timel: Y F d H:i:s}}2015 9月 02 17:40:11


#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 {{ROOTPAGENAMEHelp:Magic_words#Page_names}}.
{{#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

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 occurence 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 {{PAGENAMEHelp:Magic words#Page names}} 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:Help:Magic words#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. The list of substrings is not cleaned up hierarchically (unlike with the {{PAGENAMEHelp:Magic words#Page names}} magic keyword, the ./ and ../ relative path segments are left intact by #titleparts):
    {{#titleparts: ../c/d }}../c/d
    {{PAGENAME: ../c/d }} → '
  4. 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
Warning Warning: 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
Warning Warning: 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.
Warning Warning: 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.


General points

Substitution

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.
Warning Warning: 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>Extension:Cite#Substitution and embedded parser functions, you can use {{subst:#tag:ref|}} for this purpose.

Redirects

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 create the template 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: &#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;
|


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

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

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

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

参见