Gideros Downloader

[Updated 2012-05-10 with UrlLoader, compatible with Gideros 2012.2.2 and later]

[Updated 2012-11-01: If you think "live coding" is awesome, you really need to check out ZeroBrane Studio, in particular, this video]

Want to run an iPhone (or Android device) app built with Gideros Studio (developer account required) and simultaneously change it's source code and have those changes affect the running app (aka "live coding")? This also allows you to edit on an iPad using Textastic or other Dropbox capable editor and immediately run the code on an iPhone. I've been doing this and it works great.

By the way, you should never try to get an app on the AppStore that does this. It's one of the the main reasons the AppStore is curated, to prevent this. If you did it and got it past the reviewers, you'd likely have your developer account revoked when caught. Only do this on your iPhone using Xcode and your own developer account.

Here is a video showing this in action.

[Clarification about putting "this" on Apple's AppStore: you may put Gideros apps on Apple's AppStore, you just can't put this downloader app on Apple's AppStore because it downloads and executes code and Apple doesn't allow that.]

Here are the current instructions.

Put the code below in a Gideros Studio project.
Put a file on some webserver (like your Dropbox Public folder).
Get the link to the file (use the Dropbox website).
Find downloadURLs in the code and put your url there.
If you need to download other images, put the url's in downloadURLs.
Find loader = FileLoader.new(downloadURLs, "main.lua") and replace main.lua with the file you want to run.
Export the project and put it on your device.
Run the app on your mobile device.

Here is the code (Note, this version uses UrlLoader and is compatible with Gideros 2012.2.2 and later).

function exists(fname)
    local f = io.open(fname, "r")
    if (f and f:read()) then return true end
end
FileLoader = Core.class()
function FileLoader:onComplete(event)
    local out = io.open("|D|"..self.currentFilename, "wb")
    out:write(event.data)
    out:close()
    self.info:setText(self.currentFilename.." downloaded")
    print(self.currentURL.." downloaded")
    self:step()
end
function FileLoader:onError()
    self.info:setText("error downloading "..self.currentFilename)
    print("error downloading "..self.currentURL)
end
function FileLoader:onProgress(event)
    self.info:setText("progress: " .. event.bytesLoaded .. " of " .. event.bytesTotal)
    print("progress: " .. event.bytesLoaded .. " of " .. event.bytesTotal)
end
function FileLoader:step()
    if ( table.getn(self.urls) >= self.currentDownload ) then
        self.currentURL = self.urls[self.currentDownload]
        self.currentDownload = self.currentDownload +1
        self.currentFilename = string.match(self.currentURL, ".*/(.*)" )
        local download = not exists("|D|"..self.currentFilename)
        download = true
        if download then
            self.info:setText("loading "..self.currentFilename)
            print("loading "..self.currentURL)
            self.loader = UrlLoader.new(self.currentURL)
            self.loader:addEventListener(Event.COMPLETE, self.onComplete, self)
            self.loader:addEventListener(Event.ERROR, self.onError, self)
            self.loader:addEventListener(Event.PROGRESS, self.onProgress, self)
        else
            self.info:setText(self.currentFilename.." exists")
            self:step()
        end
    else
        success, error = pcall( function() dofile("|D|"..self.dofile) end )
        if ( success ) then
            self.info:setText("")
        else
            self.info:setText(error)
        end
    end
end
function FileLoader:init(urls, dofile)
    self.urls = urls
    self.finishedUrls = {}
    self.dofile = dofile
    self.info = TextField.new(nil, "")
    self.info:setPosition(10, 10)
    stage:addChild(self.info)
end
function FileLoader:start()
    self.info:setText("loading files...")
    self.currentDownload = 1
    self:step()
end
--------------------------------------------------
Texture.oldNew = Texture.new
function Texture.new(filename, filtering, options)
    if exists(filename) then
        return Texture.oldNew(filename, filtering, options)
    elseif exists("|D|"..filename) then
        return Texture.oldNew("|D|"..filename, filtering, options)
    else
        return nil
    end
end
--------------------------------------------------

local downloadURLs = {
    "http://dl.dropbox.com/u/1234yourid/main.lua",
}

application:setOrientation(Application.LANDSCAPE_LEFT)

seconds = 0 -- 0 doesn't reload
repeatCount = 1
loader = FileLoader.new(downloadURLs, "main.lua")

loader:start()
if seconds > 0 then
    local timer = Timer.new(seconds * 1000, 0)
    local function onTimer(event)
        repeatCount = repeatCount + 1
        loader:start()
    end
    timer:addEventListener(Event.TIMER, onTimer)
    timer:start()
end

When you run the app it will show that it is downloading the file(s) and run them. Every 2 seconds it will download your file(s) again and run them again. The state of the downloaded file is maintained each time it is downloaded, so variables hold their values from the previous time. You have to write the downloaded file a certain way for it not to stomp on itself. Here is a basic example of a file you could download.

if ( myinfo == nil ) then
    myinfo = TextField.new(nil, "loading files...")
    myinfo:setPosition(10, 30)
    stage:addChild(myinfo)
end
myinfo:setText("current repeat: "..repeatCount)

Notice it has a first run check by seeing if the myinfo variable is nil or not. Then the code below it will run every time that it is downloaded.

Normally in a Gideros app you will have everything happening inside of an event handler. So I wanted to see how this worked with that. Because addEventListener keeps a reference to the function, if you redefine the function, the event listener will keep the old one around. So you need to remove it and then re-add the new one. Here's an example.

[Updated: March 25, 2012 - had to move stage:removeEventListener() to the top before onEnterFrame() is redefined so that it works right.]

if ( firstime ~= nil ) then
    stage:removeEventListener(Event.ENTER_FRAME, onEnterFrame)
end

function onEnterFrame(event)
    x = oh:getX()
    if x > width or x < 0 then
        oh.directionX = -oh.directionX
    end
    oh:setPosition(x+oh.speed*oh.directionX, height/4)
end

if ( firstime == nil ) then
    firstime = 1
    width = application:getContentWidth()
    height = application:getContentHeight()
    oh = TextField.new(nil, "O")
    oh.directionX = 1
    stage:addChild(oh)
    stage:addEventListener(Event.ENTER_FRAME, onEnterFrame)
    oh.speed = 3
else
    stage:addEventListener(Event.ENTER_FRAME, onEnterFrame)
end

Enjoy, I'm going to have a lot of fun with this.

Published: 2012-03-21, last edited: 2020-05-11