Difference between revisions of "Module:Yesno"

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(use parent args again)
(better code for getting args)
Line 12: Line 12:
 
     -- Allow arguments to override defaults. Arguments are taken from
 
     -- Allow arguments to override defaults. Arguments are taken from
 
     -- the parent frame; other arguments are ignored.
 
     -- the parent frame; other arguments are ignored.
     for k,v in pairs(frame:getParent().args) do
+
     local args;
 +
    if frame == mw.getCurrentFrame() then
 +
        -- We're being called via #invoke. If the invoking template passed any args, use
 +
        -- them. Otherwise, use the args that were passed into the template.
 +
        args = frame:getParent().args;
 +
        for k, v in pairs(frame.args) do
 +
            args = frame.args;
 +
            break
 +
        end
 +
    else
 +
        -- We're being called from another module or from the debug console, so assume
 +
        -- the args are passed in directly.
 +
        args = frame;
 +
    end
 +
   
 +
    for k,v in pairs(args) do
 
         retvals[k] = v
 
         retvals[k] = v
 
     end
 
     end
  
     val = frame:getParent().args[1]
+
     val = args[1]
  
 
     -- First deal with the case if val is nil, then deal with other cases.
 
     -- First deal with the case if val is nil, then deal with other cases.
Line 26: Line 41:
 
     val = val:match'^%s*(.*%S)' or ''  -- Trim whitespace.
 
     val = val:match'^%s*(.*%S)' or ''  -- Trim whitespace.
  
    -- Cases are ordered by (probable) likelihood of use.
 
 
     if val == '' then
 
     if val == '' then
 
         return retvals['blank'] or retvals['no']
 
         return retvals['blank'] or retvals['no']
     elseif val == 'yes' then
+
     elseif val == 'n' or val == 'no' or tonumber(val) == 0 then
        return retvals['yes']
 
    elseif val == 'no' then
 
 
         return retvals['no']
 
         return retvals['no']
     elseif val == 'y' then
+
     elseif val == 'y' or val == 'yes' or tonumber(val) == 1 then
 
         return retvals['yes']
 
         return retvals['yes']
    elseif val == 'n' then
 
        return retvals['no']
 
 
     elseif val == '¬' then
 
     elseif val == '¬' then
 
         return retvals['¬']
 
         return retvals['¬']
    elseif tonumber(val) == 1 then
 
        return retvals['yes']
 
    elseif tonumber(val) == 0 then
 
        return retvals['no']
 
 
     else
 
     else
 
         return retvals['def'] or retvals['yes']
 
         return retvals['def'] or retvals['yes']

Revision as of 10:25, 28 March 2013

Lua error in Module:Message_box at line 171: attempt to call upvalue 'yesno' (a table value). Lua error in Module:Message_box at line 171: attempt to call upvalue 'yesno' (a table value).Lua error in Module:Category_handler at line 76: attempt to call upvalue 'yesno' (a table value). Lua error in Module:Message_box at line 171: attempt to call upvalue 'yesno' (a table value). 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 "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.

Syntax

yesno(value, default)

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.

local yesno = require('Module:Yesno')

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

-- 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)

String values are converted to lower case before they are matched:

-- 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')

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.

-- 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')

Note that the blank string also functions this way:

yesno('')        -- Returns nil.
yesno('', true)  -- Returns true.
yesno('', 'bar') -- Returns "bar".

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.


local p = {}

function p.yesno(frame)

    -- defaults
    local retvals = {
        yes   = "yes",
        no    = "",
        ["¬"] = ""
    }

    -- Allow arguments to override defaults. Arguments are taken from
    -- the parent frame; other arguments are ignored.
    local args;
    if frame == mw.getCurrentFrame() then
        -- We're being called via #invoke. If the invoking template passed any args, use
        -- them. Otherwise, use the args that were passed into the template.
        args = frame:getParent().args;
        for k, v in pairs(frame.args) do
            args = frame.args;
            break
        end
    else
        -- We're being called from another module or from the debug console, so assume
        -- the args are passed in directly.
        args = frame;
    end
    
    for k,v in pairs(args) do
        retvals[k] = v
    end

    val = args[1]

    -- First deal with the case if val is nil, then deal with other cases.
    if val == nil then
        return retvals['¬']
    end

    val = val:lower()          -- Make lowercase.
    val = val:match'^%s*(.*%S)' or ''  -- Trim whitespace.

    if val == '' then
        return retvals['blank'] or retvals['no']
    elseif val == 'n' or val == 'no'  or tonumber(val) == 0 then
        return retvals['no']
    elseif val == 'y' or val == 'yes' or tonumber(val) == 1 then
        return retvals['yes']
    elseif val == '¬' then
        return retvals['¬']
    else
        return retvals['def'] or retvals['yes']
    end
end

return p