Module:Yesno

{{#switch:<translate></translate> | = Template:Languages Template:Shared Template Warning Template:High-risk Template:Used in system Template:Module rating Template:Module rating <translate> This module provides a consistent interface for processing boolean or boolean-style string input.</translate> <translate> While Lua allows the <tvar name=1>true</tvar> and <tvar name=2>false</tvar> boolean values, wikicode templates can only express boolean values through strings such as <tvar name=3>"1"</tvar>, <tvar name=4>"0"</tvar>, <tvar name=5>"yes"</tvar>, <tvar name=6>"no"</tvar>, etc.</translate> <translate> This module processes these kinds of strings and turns them into boolean input for Lua to process.</translate> <translate> It also returns <tvar name=1>nil</tvar> values as <tvar name=1>nil</tvar>, to allow for distinctions between <tvar name=1>nil</tvar> and <tvar name=2>false</tvar>.</translate> <translate> The module also accepts other Lua structures as input, i.e. booleans, numbers, tables, and functions.</translate> <translate> If it is passed input that it does not recognise as boolean or <tvar name=1>nil</tvar>, it is possible to specify a default value to return.</translate> <translate>

Module Quality

</translate> Template:ModuleQuality <translate>

Syntax

</translate> <syntaxhighlight lang="lua"> yesno(value, default) </syntaxhighlight>

<translate> <tvar name=1>value</tvar> is the value to be tested.</translate> <translate> Boolean input or boolean-style input (see below) always evaluates to either <tvar name=1>true</tvar> or <tvar name=2>false</tvar>, and <tvar name=3>nil</tvar> always evaluates to <tvar name=3>nil</tvar>.</translate> <translate> Other values evaluate to <tvar name=1>default</tvar>.</translate> <translate>

Usage

</translate> <translate> First, load the module. Note that it can only be loaded from other Lua modules, not from normal wiki pages.</translate> <translate> For normal wiki pages you can use <tvar name=1>{{yesno}}</tvar> instead.</translate>

<syntaxhighlight lang="lua"> local yesno = require('Module:Yesno') </syntaxhighlight>

<translate> Some input values always return <tvar name=1>true</tvar>, and some always return <tvar name=2>false</tvar>.</translate> <translate> <tvar name=1>nil</tvar> values always return <tvar name=1>nil</tvar>.</translate>

<syntaxhighlight lang="lua"> -- <translate nowrap> These always return <tvar name=1>true</tvar>:</translate> yesno('yes') yesno('y') yesno('true') yesno('t') yesno('1') yesno(1) yesno(true)

-- <translate nowrap> These always return <tvar name=1>false</tvar>:</translate> yesno('no') yesno('n') yesno('false') yesno('f') yesno('0') yesno(0) yesno(false)

-- <translate nowrap> A <tvar name=1>nil</tvar> value always returns <tvar name=1>nil</tvar>:</translate> yesno(nil) </syntaxhighlight> <translate> String values are converted to lower case before they are matched: </translate> <syntaxhighlight lang="lua"> -- <translate nowrap> These always return <tvar name=1>true</tvar>:</translate> yesno('Yes') yesno('YES') yesno('yEs') yesno('Y') yesno('tRuE')

-- <translate nowrap> These always return <tvar name=1>false</tvar>:</translate> yesno('No') yesno('NO') yesno('nO') yesno('N') yesno('fALsE') </syntaxhighlight>

<translate> You can specify a default value if <tvar name=1>yesno</tvar> receives input other than that listed above.</translate> <translate> If you don't supply a default, the module will return <tvar name=1>nil</tvar> for these inputs.</translate>

<syntaxhighlight lang="lua"> -- <translate nowrap> These return <tvar name=1>nil</tvar>:</translate> yesno('foo') yesno({}) yesno(5) yesno(function() return 'This is a function.' end)

-- <translate nowrap> These return <tvar name=1>true</tvar>:</translate> yesno('foo', true) yesno({}, true) yesno(5, true) yesno(function() return 'This is a function.' end, true)

-- <translate nowrap> These return <tvar name=1>"bar"</tvar>:</translate> yesno('foo', 'bar') yesno({}, 'bar') yesno(5, 'bar') yesno(function() return 'This is a function.' end, 'bar') </syntaxhighlight> <translate> Note that the blank string also functions this way: </translate> <syntaxhighlight lang="lua"> yesno() -- <translate nowrap> Returns <tvar name=1>nil</tvar>.</translate> yesno(, true) -- <translate nowrap> Returns <tvar name=1>true</tvar>.</translate> yesno(, 'bar') -- <translate nowrap> Returns <tvar name=1>"bar"</tvar>.</translate> </syntaxhighlight>

<translate> Although the blank string usually evaluates to <tvar name=1>false</tvar> in wikitext, it evaluates to <tvar name=2>true</tvar> in Lua.</translate> <translate> This module prefers the Lua behaviour over the wikitext behaviour.</translate> <translate> If treating the blank string as <tvar name=1>false</tvar> is important for your module, you will need to remove blank arguments at an earlier stage of processing.</translate> {{safesubst:#if:{{safesubst:#ifeq:Yesno|sandbox|1}}{{safesubst:#ifeq:Yesno|doc|1}}|| }} | #default=

 {{#switch:

| = Template:Languages Template:Shared Template Warning Template:High-risk Template:Used in system Template:Module rating Template:Module rating This module provides a consistent interface for processing boolean or boolean-style string input. While Lua allows the true and false boolean values, wikicode templates can only express boolean values through strings such as "1", "0", "yes", "no", etc. This module processes these kinds of strings and turns them into boolean input for Lua to process. It also returns nil values as nil, to allow for distinctions between nil and false. The module also accepts other Lua structures as input, i.e. booleans, numbers, tables, and functions. If it is passed input that it does not recognise as boolean or nil, it is possible to specify a default value to return.

Module Quality

Template:ModuleQuality

Syntax

<syntaxhighlight lang="lua"> yesno(value, default) </syntaxhighlight>

value is the value to be tested. Boolean input or boolean-style input (see below) always evaluates to either true or false, and nil always evaluates to nil. Other values evaluate to default.

Usage

First, load the module. Note that it can only be loaded from other Lua modules, not from normal wiki pages. For normal wiki pages you can use {{yesno}} instead.

<syntaxhighlight lang="lua"> local yesno = require('Module:Yesno') </syntaxhighlight>

Some input values always return true, and some always return false. nil values always return nil.

<syntaxhighlight lang="lua"> -- These always return true: yesno('yes') yesno('y') yesno('true') yesno('t') yesno('1') yesno(1) yesno(true)

-- These always return false: yesno('no') yesno('n') yesno('false') yesno('f') yesno('0') yesno(0) yesno(false)

-- A nil value always returns nil: yesno(nil) </syntaxhighlight> String values are converted to lower case before they are matched: <syntaxhighlight lang="lua"> -- These always return true: yesno('Yes') yesno('YES') yesno('yEs') yesno('Y') yesno('tRuE')

-- These always return false: yesno('No') yesno('NO') yesno('nO') yesno('N') yesno('fALsE') </syntaxhighlight>

You can specify a default value if yesno receives input other than that listed above. If you don't supply a default, the module will return nil for these inputs.

<syntaxhighlight lang="lua"> -- These return nil: yesno('foo') yesno({}) yesno(5) yesno(function() return 'This is a function.' end)

-- These return true: yesno('foo', true) yesno({}, true) yesno(5, true) yesno(function() return 'This is a function.' end, true)

-- These return "bar": yesno('foo', 'bar') yesno({}, 'bar') yesno(5, 'bar') yesno(function() return 'This is a function.' end, 'bar') </syntaxhighlight> Note that the blank string also functions this way: <syntaxhighlight lang="lua"> yesno() -- Returns nil. yesno(, true) -- Returns true. yesno(, 'bar') -- Returns "bar". </syntaxhighlight>

Although the blank string usually evaluates to false in wikitext, it evaluates to true in Lua. This module prefers the Lua behaviour over the wikitext behaviour. If treating the blank string as false is important for your module, you will need to remove blank arguments at an earlier stage of processing. {{safesubst:#if:{{safesubst:#ifeq:Yesno|sandbox|1}}{{safesubst:#ifeq:Yesno|doc|1}}|| }} | #default=

 Lua error: expandTemplate: template loop detected.

}} }}

-- Function allowing for consistent treatment of boolean-like wikitext input.
-- It works similarly to the template {{yesno}}.

return function (val, default)
	-- If your wiki uses non-ascii characters for any of "yes", "no", etc., you
	-- should replace "val:lower()" with "mw.ustring.lower(val)" in the
	-- following line.
	val = type(val) == 'string' and val:lower() or val
	if val == nil then
		return nil
	elseif val == true 
		or val == 'yes'
		or val == 'y'
		or val == 'true'
		or val == 't'
		or val == 'on'
		or tonumber(val) == 1
	then
		return true
	elseif val == false
		or val == 'no'
		or val == 'n'
		or val == 'false'
		or val == 'f'
		or val == 'off'
		or tonumber(val) == 0
	then
		return false
	else
		return default
	end
end