TLua Engine.lua

TLua = {
    content = nil,
    data = nil,
    exportedData = nil,
}

function TLua.checkContent()
    if string.sub(TLua.content, -5) == '.tlua' then
        TLua.content = TLua.getFileContent(TLua.content)
    end
end

function TLua.getFileContent(filename)
    local handler = assert(io.open(filename, 'r'))
    local content = handler:read('*all')
    handler:close()

    -- Trim trailing newline
    if content:sub(-1) == '\n' then
        content = content:sub(1, -2)
    end

    return content
end

function TLua.render(content, data)
    TLua.content = content
    TLua.data = data or {}

    TLua.checkContent()
    TLua.exportData()

    TLua.replaceCode()
    TLua.replaceVars()
    TLua.replaceFiles()

    return TLua.content
end

function TLua.replaceVars()
    for key, value in pairs(TLua.data) do
        local realValue = ''
        if type(value) == 'number' or type(value) == 'string' or type(value) == 'boolean' then
            realValue = value
        end
        TLua.content = TLua.content:gsub('{{%s-' .. key .. '%s-}}', TLua.escapePattern(realValue))
    end
end

function TLua.replaceCode()
    for placeholder, code in TLua.content:gmatch('({{{(.-)}}})') do
        TLua.content = TLua.content:gsub(TLua.escapePattern(placeholder), TLua.escapePattern(TLua.runCode(code)))
    end
end

function TLua.replaceFiles()
    for placeholder, filename in TLua.content:gmatch('(@include%((.-)%))') do
        TLua.content = TLua.content:gsub(TLua.escapePattern(placeholder), TLua.escapePattern(TLua.getFileContent(filename)))
    end
end

function TLua.runCode(code)
    code = TLua.exportedData .. '\n' .. 'return ' .. code
    local func = loadstring(code)
    return func()
end

function TLua.exportData()
    TLua.exportedData = ''

    if next(TLua.data) ~= nil then
        local keys, values = {}, {}
        for key, value in pairs(TLua.data) do
            table.insert(keys, key)

            if (type(value) == 'number') then
                table.insert(values, tostring(value))
            elseif (type(value) == 'string') then
                table.insert(values, string.format('%q', value))
            end
        end

        TLua.exportedData = 'local ' .. table.concat(keys, ', ') .. ' = ' .. table.concat(values, ', ')
    end
end

-- Taken from https://github.com/lua-nucleo/lua-nucleo
function TLua.escapePattern(content)
    local matches = {
        ["^"] = "%^";
        ["$"] = "%$";
        ["("] = "%(";
        [")"] = "%)";
        ["%"] = "%%";
        ["."] = "%.";
        ["["] = "%[";
        ["]"] = "%]";
        ["*"] = "%*";
        ["+"] = "%+";
        ["-"] = "%-";
        ["?"] = "%?";
        ["\0"] = "%z";
    }

    return (content:gsub(".", matches))
end