Skip to main content

Friday night javascript notes

Uhg! A few things that are worth writing down - the kind of things you know but then forget you know when you are programming.



First - The DOM is case sensitive in Firefox, not in I.E. though... So imageId3 is different than ImageId3 as far as Mozilla is concerned.



O.K. that first one is like Duh! but this second point is not so much, as it turns out that if you have a variable that hasn't been assigned yet I.E. doesn't really care so much, you can try and talk to it and nothing happens - Firefox on the other hand blows up, at the least the function does. the minute you try and access that null variable Mozilla throws an error and the rest of the function won't execute. The trick is to see if there is a value assigned to it. I searched the web for a while and finally over at webdeveloper.com someone gave me this code.



if(typeof imageContainer == 'undefined')



There is an explanation at the original post. http://webdeveloper.com/forum/showthread.php?p=990761#post990761



OK - That's it for now, hope that helps you out on your JS travels.

Comments

Popular posts from this blog

Unit testing static methods when using Membership and ProfileBase in MVC 4

So you might be thinking that you want to use the Membership class and the ProfileBase class in Microsoft’s System.Web.Security and System.Web.Providers but then you also want to write unit tests as well so you decide to go stand in traffic instead once you are overcome by the plethora of static nonsense that is the design of these two classes. OK, so it isn’t that bad but it is frustrating however there are ways around it and I wanted to try and blog about some of those techniques in the hope that others won’t have to toil with as much frustration as I did when using these classes. Backgound Basically I wanted to find a clean simple way of making use of and extending Microsofts built in forms authentication. It’s easy to use, relatively secure and can save a lot of time and code, well sort of until you want to unit test. The ProfileBase class is great for extending profiles and adding custom properties so you don’t have to introduce a whole lot of redundant code. A good example of...

Musings on using a module catalog with Prism

anyone using prism is probably familar with the bootstrapper, the documentation defines the bootstrapper as a class responsible for initialization of an application built using Prism and if you dig into the code for it you will see lots of virtual methods that you can override when setting up your application, one of those is the CreateModuleCatalog(). There are several ways to initialize your modules but using an xaml file is incredibly convenient especially if you only want certain parts of your application to load under certain conditions. Where I work we recently decided to employ this feature so that we could load a subset of the application in the warehouse and not have the sales and other modules loading up at run time, on the flip side the warehouse module doesn't load when the sales team loads the application. The great part for the developer is you don't end up with multiple code bases, your core and infrastructure is shared in one application and different people see...

Styling the combox box in WPF

If you want to play with the style of the combo box in WPF the easiest thing to do is use expression blend, drag a combo box control onto you project then click, "Edit Template" -> "Edit a copy"... This will take the entire default template for the combox box and put it into your XAML file. Now go to the XAML and you can grab the entire style and do whatever you like with it... I usually put things like this into a main poject under the solution, something like "shared" is a good name for the project... One thing that is important to note though is that you have to include a reference to the PresentationFramework.Aero assembly cause you will need the Microsoft.Windows.Themes namespace.