OOP

[Davïd]

Hello,

I'm totaly new to Lua love/2D and I did like some explanation about the following code.

Here is a first class :

Code: Select all

local AtlasScheme = {}

--[[
Atlas constructor
@return object Atlas
]]

function AtlasScheme:new()
    
    self.__index = self
    
    return setmetatable(
        {
            mapsByName = {} -- Map object by name @var table{string name, object Map}
        },
        self
    )
    
end

--[[
Add map to mapsByName
@param string name
@param object Map
]]

function AtlasScheme:addMap(name, map)
    
    self.mapsByName[name] = map

end

--[[
Link map together
@param ... string arg (mapName) 
]]

function AtlasScheme:linkMap(...)

end

--[[
@return AtlasScheme
]]

return AtlasScheme

And another one :

Code: Select all

local Atlas = {}

--[[
Atlas constructor
@param object atlasScheme
@return object Atlas
]]

function Atlas:new(atlasScheme)
    
    self.__index = self   
    
    return setmetatable(
        {
            mapsByName = atlasScheme.mapsByName -- Map object by name @var table{string name, object Map}
        },
        self
    )
    
end

--[[
Load map
@param string name 
@return object Map
]]

function Atlas:loadMap(name)
    
    local Inspect = require('libraries.inspect.inspect')
    print(Inspect(self.mapsByName))
    
    self.mapsByName[name]:load()

end

--[[
Get map
@param string name 
@return object Map
]]

function Atlas:getMap(name)
    
    return mapsByName[name]

end

--[[
@return Atlas
]]

return Atlas

And I'm trying to do is to pass an atlasScheme instance to atlas as as dependency :

Code: Select all

local Atlas = require('classes.data.Atlas')
local AtlasScheme = require('classes.data.AtlasScheme')
local Map = require('classes.data.Map')

-- dependencies

local atlasScheme = AtlasScheme:new()
local atlas = Atlas

 -- Create atlas scheme    
        
    atlasScheme:addMap('Village', Map:new('truc'))
    atlasScheme:addMap('Forest', Map:new('bidule') )
    atlasScheme:addMap('Mine', Map:new('chouette') )
    atlasScheme:linkMap('village', 'Forest')
    
    --  Create map from scheme
    
    atlas:new(atlasScheme) 

And it return an error "attempt to index field 'mapsByName (a nil value)'

I figured out that the issue is here :

Code: Select all

local atlasScheme = AtlasScheme:new()
-- local atlas = Atlas -- nope
local atlas = Atlas:new() -- instead would work

But I don't get the difference between atlas = Atlas:new() and atlas = Atlas + atlas:new()

I apologize for my French skills in english and thank's for any enlightenment.

[zorg]

Hi and welcome to the forums!

From the code i read, i don't think that's where your issue is; you define :loadMap in atlasScheme, but attempt to use :addMap, which would produce that kind of an error. Is there code you're not sharing or may that be the mistake?

(Also i'm pretty sure you wanted the thread title to be Object-Oriented Programming, or "OOP"; but it's fine like this too.)

[Davïd]

Lol, I changed topic name. POO Is french acronym but is sound like shit here right

Here's my code (last line was missing)

Code: Select all

    
    atlasScheme:addMap('Village', Map:new('truc'))
    atlasScheme:addMap('Forest', Map:new('bidule') )
    atlasScheme:addMap('Mine', Map:new('chouette') )
    atlasScheme:linkMap('village', 'Forest')
    
    --  Create map from scheme
    
    atlas:new(atlasScheme)    
    
    -- Load map
    
    atlas:loadMap('Village') -- Return error
    

Don't think there is an error here ?