Santiago Becerra santibecerra

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.
Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

Fading Actionbar

This is a quick example of how to create a fading actionbar effect like this in Appcelerator Titanium

How this works

This is actually very simple. The trick is putting the Actionbar in overlay mode by configuring the theme with windowActionBarOverlay:true. Then all you need to do is updating the color of the Actionbar, in this case by scrolling a ScrollView.

Flickr Search Example: Using Controller As syntax and ui-router resolve

Demo of loading images using the Flickr API with IonicFramework

showing ui-router functionality of controller as for cleaner looking code.

A Pen by aaron k saunders on CodePen.

License.

UPDATE: With the assets command of the TiCons CLI / Module this can be done even simpeler by calling $ ticons assets or an alloy.ymk using:

task("pre:load", function(event, logger) {
    require('ticons').assets();
});

	// There is no direct way of binding angular to elements onload event as commonly the HTML elements onload="" attribute looks into the
	// Javascript global name space (window.*) which is a big no-no. It used to be the norm back in the day of how to do things but with
	// modern frameworks like AngularJs and the such the approach has changed a lot.

	// This is just one example (and by no means the only way) of how to get Angular behave nicely with HTML elements onload event. As
	// <iframe onload="test()"> looks into window.test for a callback we need to bound the onload event to look into provided angular scope
	// for the callback.

	// NOTE: Written in ES6

	##
	## Build an Appcelerator Android Module
	## Then copy it to the default module directory
	##
	## (c) Napp ApS
	## Mads Møller
	##


	## HOW TO GUIDE

	<Alloy>
	<Window module="xp.ui">
	<Label>Hello World</Label>
	</Window>
	</Alloy>

	// Put me in: ~/Library/Application Support/Sublime Text 2/Packages/User/

	[{
	"id": "view",
	"children": [{
	"id": "layout",
	"children": [{
	"command": "set_layout",
	"caption": "Custom: 3 Pane",
	"mnemonic": "C",

	// For iOS7 only, set the window's top to 20 so they start under the status bar.
	Alloy.Globals.windowTop = (OS_IOS && parseInt(Ti.Platform.version[0], 10) >= 7) ? 20 : 0;