UrlLoader

From GiderosMobile

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Supported platforms: Platform android.pngPlatform ios.pngPlatform mac.pngPlatform pc.pngPlatform html5.pngPlatform winrt.pngPlatform win32.png
Available since: Gideros 2012.2.2
Inherits from: Object

Description


The UrlLoader class is used to download data from an URL. It can be used to download (and optionally save) text files, XML files, JSON files, image files or binary files, etc.
Downloaded data is delivered at event.data field of Event.COMPLETE event as string. Lua is eight-bit clean and so strings may contain characters with any numeric value, including embedded zeros. That means that you can store any binary data into a string.

HTTP Request Methods



UrlLoader supports GET, POST, PUT and DELETE methods. These are defined by these string constants:


  • UrlLoader.GET = "get"

  • UrlLoader.POST = "post"

  • UrlLoader.PUT = "put"

  • UrlLoader.DELETE = "delete"



Examples

The example below shows downloading an image file from an URL, saving it to the documents folder and displaying it
on the stage. This example also shows downloading progress and handling errors.


local loader = UrlLoader.new("http://example.com/image.png")

local function onComplete(event)
	local out = io.open("|D|image.png", "wb")
	out:write(event.data)
	out:close()

	local b = Bitmap.new(Texture.new("|D|image.png"))
	stage:addChild(b)
end

local function onError()
	print("error")
end

local function onProgress(event)
	print("progress: " .. event.bytesLoaded .. " of " .. event.bytesTotal)
end

loader:addEventListener(Event.COMPLETE, onComplete)
loader:addEventListener(Event.ERROR, onError)
loader:addEventListener(Event.PROGRESS, onProgress)

Uploading a file

local filename = "crate.png"
local file = io.open(filename, "rb")
local contents = file:read( "*a" )
local boundary = "somerndstring"
 
local send = "--"..boundary..
			"\r\nContent-Disposition: form-data; "..
			"name="..filename.."; filename="..filename..
			"\r\nContent-type: image/png"..
			"\r\n\r\n"..contents..
			"\r\n--"..boundary.."--\r\n";
 
local headers = {
	["Content-Type"] = "multipart/form-data; boundary="..boundary,
	["Content-Length"] = #send,
}
 
local loader = UrlLoader.new("http://localhost/gideros.php", UrlLoader.POST, headers, send)
 
loader:addEventListener(Event.COMPLETE, function(e)
	print(e.data)
end)

Methods

UrlLoader.new creates a new UrlLoader object
UrlLoader:close terminates the current loading operation
UrlLoader:ignoreSslErrors Ignores SSL certificate related errors
UrlLoader:load loads data from the specified URL

Events

Event.COMPLETE
Event.ERROR
Event.PROGRESS

Constants

UrlLoader.DELETE
UrlLoader.GET
UrlLoader.POST
UrlLoader.PUT