RSSI don’t know how many times in the past I have found myself using a class and I want to change only one of the optional parameters but it just so happens to be the last argument. In order to avoid changing the default value I have to look at the objects source code. There are two ways to avoid this issue.
The first is to create setter functions for each option. I have several problems with this solution:
- It requires time to create separate functions.
- It requires more code and that means larger file size.
- Creates more functions to document.
- I like formatting my code so that I only have have one function on each line.
- If I want to change three default options that means I will now have possibly 3 more lines of code.
The second way is to have parameter that allows options to be passed as a JSON object. It uses default options that can be over written just by sending in a JSON object specifying only the settings you want to overwrite.
Example:
1: Menu = {
2: initialize: function(button, menuElem, options)
3: {
4: this.button = (button);
5: this.menuElem = (menuElem);
6: this.setOptions(options);
7: },
8: setOptions(options)
9: {
10: this.options = { align:'center', hide:true}
11: // extra {} prevents extending with null
12: Object.extend(this.options, options || {});
13: }
14: }
15: Woo = new Menu('myButton', 'myMenu', { hide: false });
This way of doing things is not my idea. Not even close. jQuery uses it as do many others. The first place I saw it was two years ago in Rico JavaScript library.
So why am I revisiting this method of option handling? It is because my next post will cover how to port this brilliant methodology to PHP5.
Tags: jQuery, Prototype Library
