Template:If/doc - Revision history

Gelthor: 39 revisions imported: Imported from https://en.wikipedia.org/w/

2023-11-17T10:54:48Z

39 revisions imported: Imported from https://en.wikipedia.org/w/

← Older revision	Revision as of 10:54, 17 November 2023
(No difference)

wikipedia>ClydeFranklin: Rm deprecated parameter

2023-04-06T06:36:34Z

Rm deprecated parameter

← Older revision		Revision as of 06:36, 6 April 2023
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	{{stack\|{{Documentation subpage}}{{risky template~~\|98320+~~}}}}		{{stack\|{{Documentation subpage}}{{risky template}}}}
	With this template the [[Help:parser function\|parser functions]] of the [[mw:Help:Extension:ParserFunctions\|ParserFunctions]] collection with names starting with "#if" can be used in a way such that they do not [[m:Help:Newlines_and_spaces#Stripping_on_expansion\|strip spaces and newlines]] from the "then" and "else" part. Spaces still do not affect the outcome of the condition. Parameter 1 selects the if-type as "eq", "expr", "exist" or "error" (for #iferror), or empty "\|\|" for a simple if-there (for #if). The template can be repeatedly nested 6 or 7 levels, one inside the other, because the outer-most is completed before running either the then/else inner levels.		With this template the [[Help:parser function\|parser functions]] of the [[mw:Help:Extension:ParserFunctions\|ParserFunctions]] collection with names starting with "#if" can be used in a way such that they do not [[m:Help:Newlines_and_spaces#Stripping_on_expansion\|strip spaces and newlines]] from the "then" and "else" part. Spaces still do not affect the outcome of the condition. Parameter 1 selects the if-type as "eq", "expr", "exist" or "error" (for #iferror), or empty "\|\|" for a simple if-there (for #if). The template can be repeatedly nested 6 or 7 levels, one inside the other, because the outer-most is completed before running either the then/else inner levels.

wikipedia>Dinoguy1000: /* Performance considerations */ timing depends on way too many factors and this sentence was written a decade ago, so there's no way it's still accurate (assuming it ever was)

2023-02-08T00:24:59Z

Performance considerations: timing depends on way too many factors and this sentence was written a decade ago, so there's no way it's still accurate (assuming it ever was)

← Older revision		Revision as of 00:24, 8 February 2023
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	==Performance considerations==		==Performance considerations==
	Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it~~. It has been timed to run at speeds of 290 instances per second, so 29 uses would take only 0.1 s, a tenth of a second to run, to make 29 comparisons~~. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].		Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].

	'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {{tlx\|P1}} and {{tlx\|P2}} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:		'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {{tlx\|P1}} and {{tlx\|P2}} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:

wikipedia>Jnestorius: /* See also / Template:Ifexist not redirect - useful because {{if|exist| testLink | yesRtn | noRtn }} returns yesRtn if testLink is a redirect

2022-12-04T00:27:52Z

See also: *Template:Ifexist not redirect - useful because <syntaxhighlight lang="text" inline>{{if|exist| testLink | yesRtn | noRtn }}</syntaxhighlight> returns yesRtn if testLink is a redirect

← Older revision		Revision as of 00:27, 4 December 2022
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	*[[m:Template:If]]		*[[m:Template:If]]
	*[[Template:Ifnotempty]] - for simplicity and to reduce the limitations due to the expansion depth limit, this is a separate template corresponding to #if only.		*[[Template:Ifnotempty]] - for simplicity and to reduce the limitations due to the expansion depth limit, this is a separate template corresponding to #if only.
			*[[Template:Ifexist not redirect]] - useful because <syntaxhighlight lang="text" inline>{{if\|exist\| testLink \| yesRtn \| noRtn }}</syntaxhighlight> returns yesRtn if testLink is a redirect
	*[[Help:Conditional expressions]]		*[[Help:Conditional expressions]]
	<includeonly>{{Sandbox other\|\|		<includeonly>{{Sandbox other\|\|
	[[Category:If-then-else templates]]		[[Category:If-then-else templates]]
	}}</includeonly>		}}</includeonly>

wikipedia>Tamzin: /* See also */ soft-redirected in 2010

2022-09-19T10:19:48Z

wikipedia>Tamzin: /* Usage */ MOS:LISTGAP

2022-03-03T05:57:09Z

Usage: MOS:LISTGAP

← Older revision		Revision as of 05:57, 3 March 2022
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	*<syntaxhighlight lang="text" inline>{{if\|\|x\| p \| q }}</syntaxhighlight> gives "{{if\|\|x\| p \| q }}". Notice the empty first parameter, seen as two adjacent vertical bars.		*<syntaxhighlight lang="text" inline>{{if\|\|x\| p \| q }}</syntaxhighlight> gives "{{if\|\|x\| p \| q }}". Notice the empty first parameter, seen as two adjacent vertical bars.

	*<syntaxhighlight lang="text" inline>{{if\|expr\|2<3\| p \| q }}</syntaxhighlight> gives " p "		*<syntaxhighlight lang="text" inline>{{if\|expr\|2<3\| p \| q }}</syntaxhighlight> gives " p "
	*<syntaxhighlight lang="text" inline>{{if\|eq\| u \|u\| p \| q }}</syntaxhighlight> gives "{{if\|eq\| u \|u\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{if\|eq\| u \|u\| p \| q }}</syntaxhighlight> gives "{{if\|eq\| u \|u\| p \| q }}"

wikipedia>NguoiDungKhongDinhDanh: Double, not triple

2022-01-03T08:02:22Z

Double, not triple

← Older revision		Revision as of 08:02, 3 January 2022
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	*<syntaxhighlight lang="text" inline>{{#iferror:{{#expr:x}}\| p \| q }}</syntaxhighlight> gives "{{#iferror:{{#expr:x}}\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#iferror:{{#expr:x}}\| p \| q }}</syntaxhighlight> gives "{{#iferror:{{#expr:x}}\| p \| q }}"

	For example, with a template named ''Template:Template name'' containing the code <syntaxhighlight lang="text" inline>{{#ifeq: {{{parameter}}} \|u\| p \| q }}</syntaxhighlight>, entering the code <syntaxhighlight lang="text" inline>{{{Template name\|parameter=u}}}</syntaxhighlight> into an article gives "p", but <syntaxhighlight lang="text" inline>{{{Template name\|parameter=v}}}</syntaxhighlight> gives "q".		For example, with a template named ''Template:Template name'' containing the code <syntaxhighlight lang="text" inline>{{#ifeq: {{{parameter}}} \|u\| p \| q }}</syntaxhighlight>, entering the code <syntaxhighlight lang="text" inline>{{Template name\|parameter=u}}</syntaxhighlight> into an article gives "p", but <syntaxhighlight lang="text" inline>{{Template name\|parameter=v}}</syntaxhighlight> gives "q".

	The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "{{" with "}}".		The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "{{" with "}}".

wikipedia>GKFX: /* Usage */ clarify langauge

2021-10-23T10:54:39Z

Usage: clarify langauge

← Older revision		Revision as of 10:54, 23 October 2021
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	==Usage==		==Usage==
	'''Where p is ~~implemented in affirmation of the~~ statement and q is ~~implemented in negation of the~~ statement'''		'''Where p is output for a true statement and q is output for a false statement.'''

	*<syntaxhighlight lang="text" inline>{{if\|\|x\| p \| q }}</syntaxhighlight> gives "{{if\|\|x\| p \| q }}". Notice ~~the ''pair'' of vertical bars surrounding~~ the empty first parameter.		*<syntaxhighlight lang="text" inline>{{if\|\|x\| p \| q }}</syntaxhighlight> gives "{{if\|\|x\| p \| q }}". Notice the empty first parameter, seen as two adjacent vertical bars.

	*<syntaxhighlight lang="text" inline>{{if\|expr\|2<3\| p \| q }}</syntaxhighlight> gives " p "		*<syntaxhighlight lang="text" inline>{{if\|expr\|2<3\| p \| q }}</syntaxhighlight> gives " p "

wikipedia>Cedar101: /* Performance considerations */

2020-08-21T04:38:10Z

Performance considerations: <syntaxhighlight inline>

← Older revision		Revision as of 04:38, 21 August 2020
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	Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it. It has been timed to run at speeds of 290 instances per second, so 29 uses would take only 0.1 s, a tenth of a second to run, to make 29 comparisons. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].		Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it. It has been timed to run at speeds of 290 instances per second, so 29 uses would take only 0.1 s, a tenth of a second to run, to make 29 comparisons. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].

	'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {P1} and {P2} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:		'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {{tlx\|P1}} and {{tlx\|P2}} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:
	:: Example of <code>#ifexpr</code>: <~~nowiki~~>"{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}"</~~nowiki~~>		:: Example of <code>#ifexpr</code>: <syntaxhighlight lang="text" inline>"{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}"</syntaxhighlight>
	:: Result for <code>#ifexpr</code>:   "{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}" ← ''the comparison invoked'' {<nowiki/>{P1}}.		:: Result for <code>#ifexpr</code>:   "{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}" ← ''the comparison invoked'' {<nowiki/>{P1}}.
	The expansion depth of a P-if is only 4 levels deep, but nesting of the then-clause or else-clause might be more confusing than using nested levels of Template:if.		The expansion depth of a P-if is only 4 levels deep, but nesting of the then-clause or else-clause might be more confusing than using nested levels of Template:if.

	:: Example of <code>#if</code>: <~~nowiki~~>"{{P{{#if:{{{2\|x}}}\|1\|2}}\| then {2} set\| else {2} empty}}"</~~nowiki~~>		:: Example of <code>#if</code>: <syntaxhighlight lang="text" inline>"{{P{{#if:{{{2\|x}}}\|1\|2}}\| then {2} set\| else {2} empty}}"</syntaxhighlight>
	:: Result for <code>#if</code>: "{{P{{#if:{{{2\|}}}\|1\|2}}\| then {2} set\| else {2} empty}}" ← ''the comparison invoked'' {<nowiki/>{P2}}.		:: Result for <code>#if</code>: "{{P{{#if:{{{2\|}}}\|1\|2}}\| then {2} set\| else {2} empty}}" ← ''the comparison invoked'' {<nowiki/>{P2}}.

wikipedia>Cedar101: /* Usage */ `,`


2020-08-21T04:35:20Z
Usage:  <code>, <syntaxhighlight>

				
				
				
				
				
				← Older revision
				Revision as of 04:35, 21 August 2020
				
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'''Where p is implemented in affirmation of the statement and q is implemented in negation of the statement''' '''Where p is implemented in affirmation of the statement and q is implemented in negation of the statement'''



*<nowiki>{{if||x| p | q }}</nowiki> gives "{{if||x| p | q }}". Notice the ''pair'' of vertical bars surrounding the empty first parameter. *<syntaxhighlight lang="text" inline>{{if||x| p | q }}</syntaxhighlight> gives "{{if||x| p | q }}". Notice the ''pair'' of vertical bars surrounding the empty first parameter.



*<nowiki>{{if|expr|2<3| p | q }}</nowiki> gives " p " *<syntaxhighlight lang="text" inline>{{if|expr|2<3| p | q }}</syntaxhighlight> gives " p "
*<nowiki>{{if|eq| u |u| p | q }}</nowiki> gives "{{if|eq| u |u| p | q }}" *<syntaxhighlight lang="text" inline>{{if|eq| u |u| p | q }}</syntaxhighlight> gives "{{if|eq| u |u| p | q }}"
*<nowiki>{{if|exist| Help:Link | p | q }}</nowiki> gives "{{if|exist| Help:Link | p | q }}" *<syntaxhighlight lang="text" inline>{{if|exist| Help:Link | p | q }}</syntaxhighlight> gives "{{if|exist| Help:Link | p | q }}"
*<nowiki>{{if|error|{{#expr:x}}| p | q }}</nowiki> gives "{{if|error|{{#expr:x}}| p | q }}" *<syntaxhighlight lang="text" inline>{{if|error|{{#expr:x}}| p | q }}</syntaxhighlight> gives "{{if|error|{{#expr:x}}| p | q }}"



Compare: Compare:
*<nowiki>{{#if:x| p | q }}</nowiki> gives "{{#if:x| p | q }}" *<syntaxhighlight lang="text" inline>{{#if:x| p | q }}</syntaxhighlight> gives "{{#if:x| p | q }}"
*<nowiki>{{#ifexpr:2<3| p | q }}</nowiki> gives "{{#ifexpr:2<3| p | q }}" *<syntaxhighlight lang="text" inline>{{#ifexpr:2<3| p | q }}</syntaxhighlight> gives "{{#ifexpr:2<3| p | q }}"
*<nowiki>{{#ifeq: u |u| p | q }}</nowiki> gives "{{#ifeq: u |u| p | q }}" *<syntaxhighlight lang="text" inline>{{#ifeq: u |u| p | q }}</syntaxhighlight> gives "{{#ifeq: u |u| p | q }}"
*<nowiki>{{#ifexist: Help:Link | p | q }}</nowiki> gives "{{#ifexist: Help:Link | p | q }}" *<syntaxhighlight lang="text" inline>{{#ifexist: Help:Link | p | q }}</syntaxhighlight> gives "{{#ifexist: Help:Link | p | q }}"
*<nowiki>{{#iferror:{{#expr:x}}| p | q }}</nowiki> gives "{{#iferror:{{#expr:x}}| p | q }}" *<syntaxhighlight lang="text" inline>{{#iferror:{{#expr:x}}| p | q }}</syntaxhighlight> gives "{{#iferror:{{#expr:x}}| p | q }}"



For example, with a template named ''Template:Template name'' containing the code <nowiki>{{#ifeq: {{{parameter}}} |u| p | q }}</nowiki>, entering the code <nowiki>{{{Template name|parameter=u}}}</nowiki> into an article gives "p", but <nowiki>{{{Template name|parameter=v}}}</nowiki> gives "q". For example, with a template named ''Template:Template name'' containing the code <syntaxhighlight lang="text" inline>{{#ifeq: {{{parameter}}} |u| p | q }}</syntaxhighlight>, entering the code <syntaxhighlight lang="text" inline>{{{Template name|parameter=u}}}</syntaxhighlight> into an article gives "p", but <syntaxhighlight lang="text" inline>{{{Template name|parameter=v}}}</syntaxhighlight> gives "q".



The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "&#123;&#123;" with "}}". The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "&#123;&#123;" with "}}".



'''Indentation:''' If indenting the markup, care must be taken to avoid extra newlines when indenting "}}" on the next line. An extra bar pipe "|" can be added after the else-clause to complete that text, and allow "}}" to then be placed anywhere without adding a newline into the else-clause. For example: ===Indentation===
:::* <nowiki>{{if|{{{1|}}}</nowiki><br>&nbsp; &nbsp; |then found parameter 1|else no parameter 1| &larr; ''extra'' "|" ''ends else-clause''<br>}} If indenting the markup, care must be taken to avoid extra newlines when indenting "}}" on the next line. An extra bar pipe "|" can be added after the else-clause to complete that text, and allow "}}" to then be placed anywhere without adding a newline into the else-clause. For example:
:::* <syntaxhighlight lang="text">{{if|{{{1|}}}
    |then found parameter 1|else no parameter 1| ← extra "|" ends else-clause
}}</syntaxhighlight >
When the else-clause is indented to the next line, a newline (CR/LF) is added: When the else-clause is indented to the next line, a newline (CR/LF) is added:
:::* <nowiki>{{if|{{{1|}}}</nowiki><br>&nbsp; &nbsp; |then found parameter 1 &larr; ''extra newline here''<br>&nbsp; &nbsp; |else noparameter 1|<br>}} :::* <syntaxhighlight lang="text">{{if|{{{1|}}}
To indent the else-clause, split an [[HTML]]-form comment, as "&lt;!--" with next line as "--&gt;|else...". Unless each then-clause and else-clause is carefully tested, to watch for extra newlines, then the results are likely to cause broken lines, with extra line breaks for each newline. For that reason, a global edit with simple search-and-replace of "<code>{#if:</code>" to "<code>{if||</code>" is likely to leave newline problems, wherever the original markup was wrapped to indent either the else-clause or "}}" of each if-structure. Indenting the then-clause is not a problem.     |then found parameter 1 ← extra newline here
    |else noparameter 1|
}}</syntaxhighlight>
To indent the else-clause, split an [[HTML]]-form comment, as "<code>&lt;!--</code>" with next line as "<code>--&gt;|else...</code>". Unless each then-clause and else-clause is carefully tested, to watch for extra newlines, then the results are likely to cause broken lines, with extra line breaks for each newline. For that reason, a global edit with simple search-and-replace of "<code>{#if:</code>" to "<code>{if||</code>" is likely to leave newline problems, wherever the original markup was wrapped to indent either the else-clause or "}}" of each if-structure. Indenting the then-clause is not a problem.



==Performance considerations== ==Performance considerations==

← Older revision		Revision as of 04:38, 21 August 2020
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	Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it. It has been timed to run at speeds of 290 instances per second, so 29 uses would take only 0.1 s, a tenth of a second to run, to make 29 comparisons. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].		Because [[Template:If]] must prepare the parameters for <code>#if, #ifeq, #ifexpr,</code> (etc.) there is a slight overhead when using it. It has been timed to run at speeds of 290 instances per second, so 29 uses would take only 0.1 s, a tenth of a second to run, to make 29 comparisons. Each nested use adds 5 levels to the template expansion depth, so 7 nested if-templates would use 35 levels (5*7) of the [[m:Help:Expansion_depth\|41-level limit]].

	'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {P1} and {P2} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:		'''Using P-if syntax:''' A similar if-structure can be coded without '''Template:If''', by using the {{tlx\|P1}} and {{tlx\|P2}} templates in a "P-if" structure. [[Template:P1]] always returns parameter 1, and P2 returns the 2nd. So, a comparison of 4 versus 3 can be coded using P-if syntax form:
	:: Example of <code>#ifexpr</code>: <~~nowiki~~>"{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}"</~~nowiki~~>		:: Example of <code>#ifexpr</code>: <syntaxhighlight lang="text" inline>"{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}"</syntaxhighlight>
	:: Result for <code>#ifexpr</code>:   "{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}" ← ''the comparison invoked'' {<nowiki/>{P1}}.		:: Result for <code>#ifexpr</code>:   "{{P{{#ifexpr: 4 > 3\|1\|2}}\| then 4 greater\| else 4 lower}}" ← ''the comparison invoked'' {<nowiki/>{P1}}.
	The expansion depth of a P-if is only 4 levels deep, but nesting of the then-clause or else-clause might be more confusing than using nested levels of Template:if.		The expansion depth of a P-if is only 4 levels deep, but nesting of the then-clause or else-clause might be more confusing than using nested levels of Template:if.

	:: Example of <code>#if</code>: <~~nowiki~~>"{{P{{#if:{{{2\|x}}}\|1\|2}}\| then {2} set\| else {2} empty}}"</~~nowiki~~>		:: Example of <code>#if</code>: <syntaxhighlight lang="text" inline>"{{P{{#if:{{{2\|x}}}\|1\|2}}\| then {2} set\| else {2} empty}}"</syntaxhighlight>
	:: Result for <code>#if</code>: "{{P{{#if:{{{2\|}}}\|1\|2}}\| then {2} set\| else {2} empty}}" ← ''the comparison invoked'' {<nowiki/>{P2}}.		:: Result for <code>#if</code>: "{{P{{#if:{{{2\|}}}\|1\|2}}\| then {2} set\| else {2} empty}}" ← ''the comparison invoked'' {<nowiki/>{P2}}.

← Older revision		Revision as of 10:19, 19 September 2022
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	*[[m:Template:If]]		*[[m:Template:If]]
	*[[Template:Ifnotempty]] - for simplicity and to reduce the limitations due to the expansion depth limit, this is a separate template corresponding to #if only.		*[[Template:Ifnotempty]] - for simplicity and to reduce the limitations due to the expansion depth limit, this is a separate template corresponding to #if only.
	*[[Template:Switch]], for a default result
	*[[Help:Conditional expressions]]		*[[Help:Conditional expressions]]
	<includeonly>{{Sandbox other\|\|		<includeonly>{{Sandbox other\|\|
	[[Category:If-then-else templates]]		[[Category:If-then-else templates]]
	}}</includeonly>		}}</includeonly>

← Older revision		Revision as of 04:35, 21 August 2020
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	'''Where p is implemented in affirmation of the statement and q is implemented in negation of the statement'''		'''Where p is implemented in affirmation of the statement and q is implemented in negation of the statement'''

	*<~~nowiki~~>{{if\|\|x\| p \| q }}</~~nowiki~~> gives "{{if\|\|x\| p \| q }}". Notice the ''pair'' of vertical bars surrounding the empty first parameter.		*<syntaxhighlight lang="text" inline>{{if\|\|x\| p \| q }}</syntaxhighlight> gives "{{if\|\|x\| p \| q }}". Notice the ''pair'' of vertical bars surrounding the empty first parameter.

	*<~~nowiki~~>{{if\|expr\|2<3\| p \| q }}</~~nowiki~~> gives " p "		*<syntaxhighlight lang="text" inline>{{if\|expr\|2<3\| p \| q }}</syntaxhighlight> gives " p "
	*<~~nowiki~~>{{if\|eq\| u \|u\| p \| q }}</~~nowiki~~> gives "{{if\|eq\| u \|u\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{if\|eq\| u \|u\| p \| q }}</syntaxhighlight> gives "{{if\|eq\| u \|u\| p \| q }}"
	*<~~nowiki~~>{{if\|exist\| Help:Link \| p \| q }}</~~nowiki~~> gives "{{if\|exist\| Help:Link \| p \| q }}"		*<syntaxhighlight lang="text" inline>{{if\|exist\| Help:Link \| p \| q }}</syntaxhighlight> gives "{{if\|exist\| Help:Link \| p \| q }}"
	*<~~nowiki~~>{{if\|error\|{{#expr:x}}\| p \| q }}</~~nowiki~~> gives "{{if\|error\|{{#expr:x}}\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{if\|error\|{{#expr:x}}\| p \| q }}</syntaxhighlight> gives "{{if\|error\|{{#expr:x}}\| p \| q }}"

	Compare:		Compare:
	*<~~nowiki~~>{{#if:x\| p \| q }}</~~nowiki~~> gives "{{#if:x\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#if:x\| p \| q }}</syntaxhighlight> gives "{{#if:x\| p \| q }}"
	*<~~nowiki~~>{{#ifexpr:2<3\| p \| q }}</~~nowiki~~> gives "{{#ifexpr:2<3\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#ifexpr:2<3\| p \| q }}</syntaxhighlight> gives "{{#ifexpr:2<3\| p \| q }}"
	*<~~nowiki~~>{{#ifeq: u \|u\| p \| q }}</~~nowiki~~> gives "{{#ifeq: u \|u\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#ifeq: u \|u\| p \| q }}</syntaxhighlight> gives "{{#ifeq: u \|u\| p \| q }}"
	*<~~nowiki~~>{{#ifexist: Help:Link \| p \| q }}</~~nowiki~~> gives "{{#ifexist: Help:Link \| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#ifexist: Help:Link \| p \| q }}</syntaxhighlight> gives "{{#ifexist: Help:Link \| p \| q }}"
	*<~~nowiki~~>{{#iferror:{{#expr:x}}\| p \| q }}</~~nowiki~~> gives "{{#iferror:{{#expr:x}}\| p \| q }}"		*<syntaxhighlight lang="text" inline>{{#iferror:{{#expr:x}}\| p \| q }}</syntaxhighlight> gives "{{#iferror:{{#expr:x}}\| p \| q }}"

	For example, with a template named ''Template:Template name'' containing the code <~~nowiki~~>{{#ifeq: {{{parameter}}} \|u\| p \| q }}</~~nowiki~~>, entering the code <~~nowiki~~>{{{Template name\|parameter=u}}}</~~nowiki~~> into an article gives "p", but <~~nowiki~~>{{{Template name\|parameter=v}}}</~~nowiki~~> gives "q".		For example, with a template named ''Template:Template name'' containing the code <syntaxhighlight lang="text" inline>{{#ifeq: {{{parameter}}} \|u\| p \| q }}</syntaxhighlight>, entering the code <syntaxhighlight lang="text" inline>{{{Template name\|parameter=u}}}</syntaxhighlight> into an article gives "p", but <syntaxhighlight lang="text" inline>{{{Template name\|parameter=v}}}</syntaxhighlight> gives "q".

	The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "{{" with "}}".		The text of either the then-clause or else-clause is only processed and expanded when triggered. Hence, any templates in use are only expanded once the then-clause or else-clause is matched, otherwise they are skipped as merely paired braces, "{{" with "}}".

	~~'''~~Indentation~~:'''~~ If indenting the markup, care must be taken to avoid extra newlines when indenting "}}" on the next line. An extra bar pipe "\|" can be added after the else-clause to complete that text, and allow "}}" to then be placed anywhere without adding a newline into the else-clause. For example:		===Indentation===
	:::* <~~nowiki~~>{{if\|{{{1\|}}}~~</nowiki><br>   ~~ \|then found parameter 1\|else no parameter 1\| ~~← ''~~extra'' "\|" ''ends else-clause''<br>}}		If indenting the markup, care must be taken to avoid extra newlines when indenting "}}" on the next line. An extra bar pipe "\|" can be added after the else-clause to complete that text, and allow "}}" to then be placed anywhere without adding a newline into the else-clause. For example:
			:::* <syntaxhighlight lang="text">{{if\|{{{1\|}}}
			\|then found parameter 1\|else no parameter 1\| ← extra "\|" ends else-clause
			}}</syntaxhighlight >
	When the else-clause is indented to the next line, a newline (CR/LF) is added:		When the else-clause is indented to the next line, a newline (CR/LF) is added:
	:::* <~~nowiki~~>{{if\|{{{1\|}}}~~</nowiki><br>   ~~ \|then found parameter 1 ~~← ''~~extra newline here~~''<br>   ~~ \|else noparameter 1\|<br>}}		:::* <syntaxhighlight lang="text">{{if\|{{{1\|}}}
	To indent the else-clause, split an [[HTML]]-form comment, as "<!--" with next line as "-->\|else...". Unless each then-clause and else-clause is carefully tested, to watch for extra newlines, then the results are likely to cause broken lines, with extra line breaks for each newline. For that reason, a global edit with simple search-and-replace of "<code>{#if:</code>" to "<code>{if\|\|</code>" is likely to leave newline problems, wherever the original markup was wrapped to indent either the else-clause or "}}" of each if-structure. Indenting the then-clause is not a problem.		\|then found parameter 1 ← extra newline here
			\|else noparameter 1\|
			}}</syntaxhighlight>
			To indent the else-clause, split an [[HTML]]-form comment, as "<code><!--</code>" with next line as "<code>-->\|else...</code>". Unless each then-clause and else-clause is carefully tested, to watch for extra newlines, then the results are likely to cause broken lines, with extra line breaks for each newline. For that reason, a global edit with simple search-and-replace of "<code>{#if:</code>" to "<code>{if\|\|</code>" is likely to leave newline problems, wherever the original markup was wrapped to indent either the else-clause or "}}" of each if-structure. Indenting the then-clause is not a problem.

	==Performance considerations==		==Performance considerations==