About Focus on JavaScript

Referencing Form Fields

2009-11-14T15:22:35Z

Form field names are used to pass the information to the server

The names that you give to the fields in your form in order for the server side processing to work may not be appropriate to use to references them from JavaScript. Fortunately JavaScript has an alternate way of being able to reference form fields.

Referencing Form Fields

Referencing Form Fields originally appeared on About.com Focus on JavaScript on Saturday, November 14th, 2009 at 15:22:35.

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Dynamic Forms

2009-11-13T09:58:52Z

JavaScript can add complex HTML to a web page

A new addition to my library of scripts that you can use on your own site is my new Form object script which provides you with an object that has simple to use methods to create a form with all the form field types you are most likely to want to use (it doesn't handle file inputs or optgroups but most of the time you will not need those). The object uses standard DOM calls to add the form into your web page as well as providing plenty of ways to reference the fields from your stylesheet in order to format it the way you want.

Dynamic Forms

Dynamic Forms originally appeared on About.com Focus on JavaScript on Friday, November 13th, 2009 at 09:58:52.

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You Can't Protect Your Page Content

2009-11-12T09:52:58Z

Web pages are open source and there is nothing you can do to protect the content

Every so often I receive emails about my Image Protection JavaScript that places the image in the background of a table with a transparent image in front of it. All of these emails have pointed out that there are other ways to obtain the image and that it is not really protected. In fact there is no way to stop people obtaining the content of your web page since they have it already on their computer when they view your page. The same is true even if you use JavaScript to encrypt your page source since your visitors all have something that can decrypt it for them (called a web browser). In fact applying something as simple as a no right click script (which is the least effective way to try to protect anything) will just drive visitors away from your site. Any of these techniques may stop newbie web users from taking your code and images (and will do so at least as effectively as much longer codes and more expensive solutions found elsewhere on the web) but nothing will prevent someone who knows how the web works from obtaining whatever they want from your site.

You Can't Protect Your Page Content originally appeared on About.com Focus on JavaScript on Thursday, November 12th, 2009 at 09:52:58.

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Minimum and Maximum Distance

2009-11-11T18:26:28Z

How far apart are specific characters? Find out with JavaScript

Continuing with our look at validating text input fields using JavaScript, the tenth tutorial in the form validation series looks at how we can test to make sure that selected characters in the input are a certain distance apart.

Minimum and Maximum Distance

Minimum and Maximum Distance originally appeared on About.com Focus on JavaScript on Wednesday, November 11th, 2009 at 18:26:28.

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Unobtrusive Add to Favourites

2009-11-10T10:24:20Z

JavaScript can add to the page when a feature is supported and not add when it isn't.

Having an "Add to Favourites" link is popular with people just starting out writing web pages. Not all browsers support such a link though and some pople have written scripts that use the wrong way of testing if the browser does support it. This version of the "Add to Favourites" script not only uses the correct method of testing if the browser supports the link, it supplies the necessary code for all the browsers that do provide a way to support such a link, and just leaves an empty tag in the page where the link would have gone if the browser doesn't support it.

Unobtrusive Add to Favourites

Unobtrusive Add to Favourites originally appeared on About.com Focus on JavaScript on Tuesday, November 10th, 2009 at 10:24:20.

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Ignore Case and Global

2009-11-08T15:14:41Z

Regular Expressions can ignore capitals and find all matches

The second tutorial on Regular Expressions covers how to set the expression for global processing and to ignore capitalization.

Even with this most basic use of regular expressions you will be able to do searches for either the first or all occurrences of a text string. You will also be able to decide whether the exact capitalisation you used is important for obtaining a match or whether the capitalisation should be ignored.

Ignore Case and Global

Ignore Case and Global originally appeared on About.com Focus on JavaScript on Sunday, November 8th, 2009 at 15:14:41.

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JavaScript Alert

2009-11-08T07:33:43Z

You can do some quick debugging of simple JavaScripts using alert()

The alert built in function has little to no use in live JavaScript code (particularly since some browsers display an option to turn off JavaScript at the bottom of the alert) but it is still useful for finding and fixing errors in JavaScript code when you are testing in a browser that doesn't have a debugger built in (such as Firefox).

JavaScript Alert

JavaScript Alert originally appeared on About.com Focus on JavaScript on Sunday, November 8th, 2009 at 07:33:43.

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Unobtrusive JavaScript

2009-11-07T05:24:26Z

JavaScript belongs in a separate file linked from the head of your page.

There is no longer any need to clutter the body of your web page with event handlers attached to tags and scripts embedded in between content. By using a few simple coding techniques we can remove all of that from the body of the web page and place it all into a separate JavaScript file that we link into our page with a simple script tag in the head of the page.

Unobtrusive JavaScript

Unobtrusive JavaScript originally appeared on About.com Focus on JavaScript on Saturday, November 7th, 2009 at 05:24:26.

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Feature Sensing

2009-11-06T15:10:03Z

Test if the browser supports a specific JavaScript Feature directly, do not test whether the browser was one that did or didn't support that feature ten years ago.

Right from day one JavaScript has provided a simple way to check whether the version of JavaScript currently being run supports a given object, method or function. The same (or similar code) can also be used to check if a property or variable exists. Using this way of testing if the browser supports your script your script will always work in new browsers that add that support even where the prior version didn't.

Feature Sensing

Feature Sensing originally appeared on About.com Focus on JavaScript on Friday, November 6th, 2009 at 15:10:03.

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Functions and Object Constructors

2009-11-05T08:58:32Z

JavaScript doesn't have classes but objects can inherit directly from other objects

In JavaScript object constructors are defined the same way you define a function. What distinguishes one from the other is the way it is called. By testing how it was called inside your function you can make functions that are also object constructors or can test if it is called the right way.

Functions and Object Constructors

Functions and Object Constructors originally appeared on About.com Focus on JavaScript on Thursday, November 5th, 2009 at 08:58:32.

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