Include.lua

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--                       Include                       --
--  Dynamically loads a codea tab or project into and  --
--                isolated enviroment or _G            --
--                  Written by XanDDemoX               --
--                      Version 1.01                   --
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include = {}
-- create meta table
local includemeta = {}
-- debugging setup
local _debug = false
local _debugstring = ""
local function _dbgmsg(...)
 if _debug == true then for i,v in ipairs(arg) do _debugstring=_debugstring..tostring(v) end 
 _debugstring=_debugstring.."\r\n\r\n"
end end
-- access to _G from isolated project/tab enviroments
local _defaultMT = {__index = _G}
-- cache
local _loaded = {}
includemeta.__call= function (self,...)
    -- check params table
    if arg == nil then return {} end if #arg == 0 then return {} end
    local items = {}
    local valid = true
    
    -- validate items 
    for i,v in ipairs(arg) do
        if valid and type(v) ~= "string" then valid = false end
    -- check its not the main file
        if valid and string.match(v,"[%a%d_]:Main") then valid = false end
        if valid then
             -- check whether its a class key filename format
            if string.match(v,"[%a%d_]:[%a%d_]") then table.insert(items,v)-- add it too the list if it matches
            elseif string.match(v,"[%a%d_]") then
                -- otherwise assume project and get tabs list
                local tabs = listProjectTabs(v)
                if tabs == nil then _dbgmsg("Invalid project: ",v)
                elseif #tabs == 0 then _dbgmsg("Invalid project: ",v)
                else for ii,vv in ipairs(tabs) do if vv ~= "Main" then table.insert(items,v..":"..vv) end end
                end
            end
        else _dbgmsg("Invalid tab or project: ",v) end 
        valid = true
    end
    -- check if anything was valid
    if #items == 0 then return items end
    
    -- load each item in order from the list of items
    local namespace ={}
    local tabs = {}
    for i,v in ipairs(items) do
        local projname,tabname = string.match(v,"([%a%d_]+):([%a%d_]+)")
        -- create project cache
        local proj = _loaded[projname]   
        if proj == nil then 
            proj = {}
            proj.__meta=setmetatable({}, proj.__meta and { __index = proj.__meta } or _defaultMT)
            _loaded[projname] = proj
        end
        -- create tab cache
        if _loaded[projname][tabname] == nil then
            local t = readProjectTab(v)
            if t ~= nil then
                -- load tab if read was successful
                local func,err = loadstring("return function() "..t.." end")
                if func ~= nil then -- set enviroment and fully load tab 
                local md = setmetatable({}, md and {__index = md} or {__index = proj.__meta} or _defaultMT)
                    if xpcall(setfenv(func(),md),function() _dbgmsg("Error in tab: ",v) end) then 
                        -- try and call tab load if successful shallow copy into project meta table
                        -- and put reference tab meta table into cache
                        for kk,vv in pairs(md) do proj.__meta[kk]=vv end 
                        _loaded[projname][tabname] = md
                        _dbgmsg("Successfully loaded tab: ",v)
                    end
                end
            end
        end -- get tab from cache and shallow copy into return value
        local tabmeta = _loaded[projname][tabname]
        if tabmeta ~= nil then 
            for k,v in pairs(tabmeta) do 
                tabs[k] = v 
                namespace[projname] = namespace[projname] or {}
                namespace[projname][k]=v
            end 
        end
    end
    -- return tabs copied from cache
    return tabs,namespace
end
function xinclude(...)
    local ts,ns = include(...)
    return ns
end
--setup include function
setmetatable(include,includemeta)
-- expose debug messages 
include.debugstring=function() return _debugstring end
-- import the result from include into _G
function import(...) local tabs = include(...) for k,v in pairs(tabs) do _G[k]=v end return tabs end
function ximport(...) local ts,ns = include(...) for k,v in pairs(ns) do _G[k]=_G[k] or {}
    for kk,vv in pairs(v) do _G[k][kk]=vv end
end end