Tuesday, July 2, 2013

Web Fonts Dynamic Loading

In one of the applications I'm currently working on, there is a need to allow users to select  a font from a variety of Google web fonts.
Since I don't want to load all the fonts when the application loads, I've added some code to dynamically load only the selected font.
Below you can see it in action.
The code can be viewed in this jsFiddle.



Tuesday, June 25, 2013

Localization of HTML Elements

When creating a SPA (Single Page Application), many times we like it to be localization-ready,
meaning it can be easily translated to other languages. 
Without getting into the many aspects of localization (and sometimes internationalization), 
I would like to present a simple way to localize HTML elements using HTML5 "data-" attribute.

The idea is to add a key attribute to the HTML element that we want to localize. 
For example:

<span data-key="txt1"></span>

We then create a JSON file holding all the application text as key-value pairs. For example:

{
"txt1": "translated text 1",
"txt2": "translated text 2",
"txt3": "translated text 3"
}

For each language we create a separate JSON file.
When the application loads, we use jQuery to load and parse the JSON file.
Then we access each HTML element by its data-key and set its HTML to the corresponding value from the JSON data file:

  var appNS;
  (function (appNS) {
      appNS.initApp = function(){
      // load language file
      $.getJSON('en_us.json', function(data) {
        // json loaded - save to object
        appNS.Lang = data;
        for (var key in appNS.Lang)
          $('[data-key="'+key+'"]').html(appNS.Lang[key]);
        });
      }
  } (appNS = appNS || {}));
  
  $(document).ready(function () {
    appNS.initApp();
  });

In this example, I've also used a name space and a JavaScript module.
A working demo can be seen in this plnkr.


Tuesday, June 11, 2013

JavaScript Name Spaces and Modules

An important concept of modular JavaScript is name spaces usage. 
Since any variable declared in the code automatically becomes a global variable residing on the main window object, 
accidental overriding of variables could occur. Further more, code maintenance and modular components are hard to implement. 
The solution is using name spaces and JavaScript modules. Nested modules can also be easily created.
  • Name spaces are implemented using JavaScript objects.
  • Modules are achieved using JavaScript immediate functions. 
Here is a simple example:

var myAppNS;
(function (myAppNS) {
   myAppNS.prop = value;
   myAppNS.func = function() { 
      // do some stuff...
   };
} (myAppNS = myAppNS || {}));

Check out this jsfiddle to see an example.

For nested modules and nested name spaces - check out this plnkr.


From Flex to JavaScript - "The Big Switcheroo"!

So, it took me a year. 
As the rich-media world made a giant leap (or fall, depends on your point of view) from Flex / Flash back to good old JavaScript, I didn't want to be left behind. 
I've spend the last year learning new JavaScript frameworks, HTML5 / CSS3 features, new UI libraries etc. 
My future posts will probably target these new technologies. 
Bye-bye Flash, hello JavaScript!

About Me

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I've been developing Internet and rich-media application for 15 years. In my work I emphasis usability and best user experience as well as sleek design. My main expertise are JavaScript, Flex and Flash.

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