lazy-loading

I have a view controller that I want to lazily initialize, and once initialized, use the same copy when possible (I don't use a singleton since I do want to remove it from memory eventually), I use the getter to do so, my code look like this: @property (retain) UIViewController *myController ... @synthesize myController = _myController; ... - (UIViewController *)myController { if (!_myController) { // Evaluation _myController = [[MyViewController alloc] init]; // Object Creation } return _myController; } This works, but it's not thread safe, and if more than one thread evaluate to true before

My problem is the following: I have some python classes that have properties that are derived from other properties; and those should be cached once they are calculated, and the cached results should be invalidated each time the base properties are changed. I could do it manually, but it seems quite difficult to maintain if the number of properties grows. So I would like to have something like Makefile rules inside my objects to automatically keep track of what needs to be recalculated. The desired syntax and behaviour should be something like that: # this does dirty magic, like generating the

Is it bad practice to change my getter method like version 2 in my class. Version 1: public String getMyValue(){ return this.myValue } Version 2: public String getMyValue(){ if(this.myValue == null || this.myValue.isEmpty()){ this.myValue = "N/A"; } return this.myValue; } I think it is actually quite a bad practice if your getter methods change the internal state of the object. To achieve the same I would suggest just returning the "N/A" . Generally speaking this internal field might be used in other places (internally) for which you don't need to use the getter method. So in the end, the call

I'm currently redesigning my website and have been looking into using JavaScript and jQuery. Here is what I have so far: http://www.tedwinder.co.uk/gallery2/ . My vision is to have all of the photos on one page, which the user can scroll through, like now. However, I understand the limitations and effects of having 50+ large-ish images on one page and have considered using infinite scrolling and lazy loading, which I understand would only load the images when the user gets to them, or when they click on a "More" link? So, my question is: would this reduce the page load, how exactly would I go

I am looking for something similar to jQuery image lazy load plugin , but for iframe s. This worked for me. var iframes = $('iframe'); $('button').click(function() { iframes.attr('src', function() { return $(this).data('src'); }); }); iframes.attr('data-src', function() { var src = $(this).attr('src'); $(this).removeAttr('src'); return src; }); jsFiddle . technoTarek A similar question was recently posted specific to iFrames with Twitter Bootstrap-based tabs, which I answered using a technique I'm calling Lazy Loading of iFrames . The js/jquery is as follows; see the full code including html

I am looking for something similar to jQuery image lazy load plugin , but for iframe s. This worked for me. var iframes = $('iframe'); $('button').click(function() { iframes.attr('src', function() { return $(this).data('src'); }); }); iframes.attr('data-src', function() { var src = $(this).attr('src'); $(this).removeAttr('src'); return src; }); jsFiddle . technoTarek A similar question was recently posted specific to iFrames with Twitter Bootstrap-based tabs, which I answered using a technique I'm calling Lazy Loading of iFrames . The js/jquery is as follows; see the full code including html

I am using Hibernate 4.2 and build time bytecode instrumentation for solve the lazy issue that appears on a @OneToOne relation and @Lob ( https://developer.jboss.org/wiki/SomeExplanationsOnLazyLoadingone-to-one ) Do you know what is the difference between : Hibernate bytecode instrumentation : http://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html/ch20.html#performance-fetching-lazyproperties Hibernate bytecode enhancement : http://docs.jboss.org/hibernate/orm/4.3/manual/en-US/html/ch20.html#bytecode-enhancement Because on the hibernate documentation, it is written : The EnhancementTask is

I've been testing a lot of lazy-loaders for JavaScript and CSS that insert <script> and <link> tags to load files. However the problem is, that <link> tags don't fire onload so it's difficult to detect when they're loaded. The only workaround I found for this is to set display: none; (in the CSS file that is to be loaded) on a dummy element and poll that element to check when it has been set to display: none. But that, apart from being ugly, of course only works for a single CSS file. So I was wondering; Is there any other way to detect if a CSS file has been loaded? edit: It should be noted