NOTE: Titanium has built-in remote image caching for Android since 3.1 and for iOS since the early days. This is not documented, but a ticket I created for this to be done has been resolved recently. For this reason I no longer maintain this widget.

CachedImageView Widget

Overview

The CachedImageView widget implements the best practice of caching remote images for Titanium Alloy by Appcelerator.

Features

• Initialize the widget directly through the requiring view.
• Provide a seperate URL for the image to use on IOS retina devices.
• Provide a local filename to be used instead of the MD5 hash of the URL.
• Provide an extension for the local file if the remote doesn't have one.
• Eventing.

Future work

• Provide a subdirectory to save the image under.
• Provide a choice to which system directory (cache, data) to save under.
• Provide a maximum age for the cached image before re-downloading it.

Quick Start

Get it

Download this repository and consult the Alloy Documentation on how to install it, or simply use the gitTio CLI:

$ gittio install nl.fokkezb.cachedImageView

Use it

Use the widget in a view just like you'd use an ImageView. Only use Widget instead of ImageView and add the src attribute to point to the widget. Optionally add any of the additional parameters as attributes.

<Widget src="nl.fokkezb.cachedImageView"
id="civ" image="http://url.to/image.png" onClick="handleClick" />

Additonal parameters

The only required parameter is the image parameter. All parameters are passed on to the resulting Ti.UI.ImageView. You can add the following additional parameters to change the widget's behaviour. They can be used both as attributes in <Widget> and when initializing the widget in your controller.

Parameter	Type	Description
cacheHires	string	URL of the image to use for iOS retina devices.
cacheName	string	Basename for the local file instead of the MD5 hash of the URL. Use it when the URL contains some time-dependant key.
cacheExt	string	Extension for the local file if the URL doesn't have one, like with generated images.
cacheNot	string	Disable caching

Methods

Method	Params	Description
init	object	Any ImageView parameters plus the additional above
applyProperties	object	Alias for init
setImage	string	Alias for calling init with only an image parameter
getImage	bool returnPath	Return the (path to the) local image. Calling this method before it has been cached will return undefined
on / addEventListener	string name, function callback	Add an eventlistener
off / removeEventListener	string name, function callback	Remove an eventlistener
trigger / fireEvent	string name, object args	Fire an event

Properties

Property	Description
image	Alias to setImage and getImage methods

Initialization in the Controller

If you don't include the image parameter as an attribute in <Widget/>, the resulting Ti.UI.ImageView will not be automatically initialized for you. This allows you to do this yourself in your controller. This can be usefull if you want to add some advanced decission logic to determine which image to use. If this would only depend on the formFactor and platform however, I would recommend using conditional code in <Widget/> instead.

NOTE: The $.cid in the example below corresponds to the id attribute in the <Widget/> example. You can change it to whatever value. From 1.2 on you can also call the more common applyProperties.

$.cid.init({
    image: OS_IOS ? 'http://url.to/image.png' : 'http://url.to/android-image.png'
});

Styling the ImageView

You can style the resulting Ti.UI.ImageView by applying the styles to the <Widget/> instead. Add the style declaration to the TTS file that belongs to the view where you've added the <Widget/>. The styling will be passed on to the resuling Ti.UI.ImageView. Be aware that any attributes you add directly to <Widget/> will override the TTS style.

NOTE: The $.cid in the example below corresponds to the id attribute in the <Widget/> example.

"#cid": {
	width: 57,
	height: 57,
	preventDefaultImage: true
}

Changelog

• 1.4: Added events
• 1.3: Fixed bug when using blob/file, added image property and cacheNot param
• 1.2: Added getImage, setImage, applyProperties and deleted __parentSybmol
• 1.1: Support for styling via TSS before setting image via init()
• 1.0: Initial version

License

Copyright 2013 Fokke Zandbergen

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.