User:Mheguy/sandbox

local p = {} --All Lua modules on Wikipedia must begin by defining a variable

                   --that will hold their externally accessible functions.
                   --Such variables can have whatever name you want and may 
                   --also contain various data as well as functions.

p.hello = function( frame ) --Add a function to "p".

                                       --Such functions are callable in Wikipedia
                                       --via the #invoke command.
                                       --"frame" will contain the data that Wikipedia
                                       --sends this function when it runs. 
                                -- 'Hello' is a name of your choice. The same name needs to be referred to when the module is used.
   
   local str = "Hello World!"  --Declare a local variable and set it equal to
                               --"Hello World!".  
   
   return str    --This tells us to quit this function and send the information in
                 --"str" back to Wikipedia.
   

end -- end of the function "hello" function p.hello_to(frame) -- Add another function local name = frame.args[1] -- To access arguments passed to a module, use `frame.args` -- `frame.args[1]` refers to the first unnamed parameter -- given to the module return "Hello, " .. name .. "!" -- `..` concatenates strings. This will return a customized -- greeting depending on the name given, such as "Hello, Fred!" end function p.count_fruit(frame)

local num_bananas = tonumber(frame.args.bananas) or 0 -- Named arguments ({{#invoke:Example|count_fruit|foo=bar}}) local num_apples = tonumber(frame.args.apples) or 0 -- are likewise accessed by indexing `frame.args` by name (`frame.args["bananas"]`, -- or equivalently `frame.args.bananas`.

local conj_bananas = num_bananas == 1 and 'banana' or 'bananas'

   local conj_apples = num_apples == 1 and 'apple' or 'apples'
   										-- Ternary operators assign values based on a condition in a compact way.

-- Here, `conj_bananas` gets `'banana'` if `num_bananas` is 1, else `'bananas'`. -- Similarly, `conj_apples` gets `'apple'` if `num_apples` is 1, else `'apples'`.

   return 'I have ' .. num_bananas ..  ' ' .. conj_bananas .. ' and ' .. num_apples .. ' ' .. conj_apples														

-- Like above, concatenate a bunch of strings together to produce -- a sentence based on the arguments given. end

return p --All modules end by returning the variable containing their functions to Wikipedia. -- Now we can use this module by calling {{#invoke: Example | hello }}, -- {{#invoke: Example | hello_to | foo }}, or {{#invoke:Example|count_fruit|bananas=5|apples=6}} -- Note that the first part of the invoke is the name of the Module's wikipage, -- and the second part is the name of one of the functions attached to the -- variable that you returned.

-- The "print" function is not allowed in Wikipedia. All output is accomplished -- via strings "returned" to Wikipedia.