Difference between revisions of "UrlLoader"

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__NOTOC__
 
__NOTOC__
'''Supported platforms:''' android, ios, mac, pc<br/>
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<languages />
'''Available since:''' Gideros 2012.2.2<br/>
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<!-- GIDEROSOBJ:UrlLoader -->
=== Description ===
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'''<translate>Supported platforms</translate>:''' [[File:Platform android.png]][[File:Platform ios.png]][[File:Platform mac.png]][[File:Platform pc.png]][[File:Platform html5.png]][[File:Platform winrt.png]][[File:Platform win32.png]]<br/>
<br />
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'''<translate>Available since</translate>:''' Gideros 2012.2.2<br/>
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.<br />
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'''<translate>Inherits from</translate>:''' [[Special:MyLanguage/Object|Object]]<br/>
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.<br />
 
  
<h3>HTTP Request Methods</h3><br />
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=== <translate>Description</translate> ===
<br />
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The [[Special:MyLanguage/UrlLoader|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.
UrlLoader supports GET, POST, PUT and DELETE methods. These are defined by these string constants:<br />
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<br />
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Downloaded data is delivered at ''event.data'' field of [[Special:MyLanguage/Event.COMPLETE|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.
<ul><br />
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<li>`UrlLoader.GET = "get"`</li><br />
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==== HTTP Request Methods ====
<li>`UrlLoader.POST = "post"`</li><br />
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UrlLoader supports GET, POST, PUT and DELETE methods. These are defined by these string constants:
<li>`UrlLoader.PUT = "put"`</li><br />
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<ul>
<li>`UrlLoader.DELETE = "delete"`</li><br />
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<li>''UrlLoader.GET = "get"''</li>
</ul><br />
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<li>''UrlLoader.POST = "post"''</li>
<br />{|-
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<li>''UrlLoader.PUT = "put"''</li>
| style="width: 50%;"|
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<li>''UrlLoader.DELETE = "delete"''</li>
=== Methods ===
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</ul>
[[UrlLoader.new]] - creates a new UrlLoader object<br/>
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[[UrlLoader:close]] - terminates the current loading operation<br/>
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=== <translate>Examples</translate> ===
[[UrlLoader:ignoreSslErrors]] - Ignores SSL certificate related errors<br/>
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'''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:'''
[[UrlLoader:load]] - loads data from the specified URL<br/>
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<source lang="lua">
| style="width: 50%;"|
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local loader = UrlLoader.new("http://example.com/image.png")
=== Events ===
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[[Event.COMPLETE]]<br/>
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local function onComplete(event)
[[Event.ERROR]]<br/>
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local out = io.open("|D|image.png", "wb")
[[Event.PROGRESS]]<br/>
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out:write(event.data)
=== Constants ===
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out:close()
[[UrlLoader.DELETE]]<br/>
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[[UrlLoader.GET]]<br/>
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local b = Bitmap.new(Texture.new("|D|image.png"))
[[UrlLoader.POST]]<br/>
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stage:addChild(b)
[[UrlLoader.PUT]]<br/>
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end
 +
 
 +
local function onError()
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print("error")
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end
 +
 
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local function onProgress(event)
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print("progress: " .. event.bytesLoaded .. " of " .. event.bytesTotal)
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end
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loader:addEventListener(Event.COMPLETE, onComplete)
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loader:addEventListener(Event.ERROR, onError)
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loader:addEventListener(Event.PROGRESS, onProgress)
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</source>
 +
 
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'''Uploading a file:'''
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<source lang="lua">
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local filename = "crate.png"
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local file = io.open(filename, "rb")
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local contents = file:read( "*a" )
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local boundary = "somerndstring"
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local send = "--"..boundary..
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"\r\nContent-Disposition: form-data; "..
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"name="..filename.."; filename="..filename..
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"\r\nContent-type: image/png"..
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"\r\n\r\n"..contents..
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"\r\n--"..boundary.."--\r\n";
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local headers = {
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["Content-Type"] = "multipart/form-data; boundary="..boundary,
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["Content-Length"] = #send,
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}
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local loader = UrlLoader.new("http://localhost/gideros.php", UrlLoader.POST, headers, send)
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loader:addEventListener(Event.COMPLETE, function(e)
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print(e.data)
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end)
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</source>
 +
 
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{|-
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| style="width: 50%; vertical-align:top;"|
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=== <translate>Methods</translate> ===
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[[Special:MyLanguage/UrlLoader.new|UrlLoader.new]] ''<translate>creates a new UrlLoader object</translate>''<br/><!-- GIDEROSMTD:UrlLoader.new(url,method,headers,body) creates a new UrlLoader object -->
 +
[[Special:MyLanguage/UrlLoader:close|UrlLoader:close]] ''<translate>terminates the current loading operation</translate>''<br/><!-- GIDEROSMTD:UrlLoader:close() terminates the current loading operation -->
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[[Special:MyLanguage/UrlLoader:ignoreSslErrors|UrlLoader:ignoreSslErrors]] ''<translate>Ignores SSL certificate related errors</translate>''<br/><!-- GIDEROSMTD:UrlLoader:ignoreSslErrors() Ignores SSL certificate related errors -->
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[[Special:MyLanguage/UrlLoader:load|UrlLoader:load]] ''<translate>loads data from the specified URL</translate>''<br/><!-- GIDEROSMTD:UrlLoader:load(url,method,headers,body) loads data from the specified URL -->
 +
 
 +
| style="width: 50%; vertical-align:top;"|
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=== <translate>Events</translate> ===
 +
<!--[[Special:MyLanguage/Event.COMPLETE|Event.COMPLETE]]<br/>-->
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[[Special:MyLanguage/UrlLoader_Event.COMPLETE|UrlLoader_Event.COMPLETE]]<br/>
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<!-- GIDEROSEVT:Event.COMPLETE complete-->
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[[Special:MyLanguage/Event.ERROR|Event.ERROR]]<br/>
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<!-- GIDEROSEVT:Event.ERROR error-->
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[[Special:MyLanguage/Event.PROGRESS|Event.PROGRESS]]<br/>
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<!-- GIDEROSEVT:Event.PROGRESS progress-->
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=== <translate>Constants</translate> ===
 +
[[Special:MyLanguage/UrlLoader.DELETE|UrlLoader.DELETE]]<br/><!-- GIDEROSCST:UrlLoader.DELETE delete-->
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[[Special:MyLanguage/UrlLoader.GET|UrlLoader.GET]]<br/><!-- GIDEROSCST:UrlLoader.GET get-->
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[[Special:MyLanguage/UrlLoader.POST|UrlLoader.POST]]<br/><!-- GIDEROSCST:UrlLoader.POST post-->
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[[Special:MyLanguage/UrlLoader.PUT|UrlLoader.PUT]]<br/><!-- GIDEROSCST:UrlLoader.PUT put-->
 
|}
 
|}
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 +
{{GIDEROS IMPORTANT LINKS}}

Revision as of 20:06, 11 February 2020


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

UrlLoader_Event.COMPLETE
Event.ERROR
Event.PROGRESS

Constants

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