Apr 062013
 

To prevent a Phonegap-wrapped app from opening external links in the apps webview, use javascript to open the link in the external browser.

This works on Android (probably other platforms as well)

<a href="#" data-rel="external" target="_blank" onclick="window.open('http://www.jymden.com', '_system')">Jymden</a>
May 082012
 

Sometimes you want to show or hide certain elements of a form, depending on the selection of a radiobutton.

 

I am by no means any javascript ninja, but this is one simple way I came up with:

<html>
<head>
<script type="text/javascript">
	function DisplayElement(element)
	{
		x = element.value;
		if (x == 1) {
			document.getElementById('text').style.display = '';
		}
		else {
			document.getElementById('text').style.display = 'none';
		}
	}
</script>
</head>

<body>
<form name="form">
<input name="choice" type="radio" value="1" onclick="DisplayElement(this)" checked/>
<input name="choice" type="radio" value="2" onclick="DisplayElement(this)"/>
<input name="text" type="text" id="text"/>
</form>
</body>
</html>

 
This could apply to any element. For example, you could put a whole bunch of elements in a div and the hide/show the div. Like this:


<script type="text/javascript">
	function DisplayElement(element)
	{
		x = element.value;
		if (x == 1) {
			document.getElementById('container').style.display = '';
		}
		else {
			document.getElementById('container').style.display = 'none';
		}
	}
</script>

<form name="form">
<input name="choice" type="radio" value="1" onclick="DisplayElement(this)" checked/>
<input name="choice" type="radio" value="2" onclick="DisplayElement(this)"/>
<div id="container">
	<input type="checkbox"/>
	<input type="checkbox"/>
	<input type="text"/>
	<input type="text"/>
	<input type="text"/>
</div>
</form>

 
 
Here’s another way to do it. This example takes a number as a parameter instead of using the value of the element. A bit more compact code and it might be more flexible.

<script type="text/javascript">
    function DisplayElement(x)
    {
        if (x == 1) {
            document.getElementById('text').style.display = '';
        }
        else {
            document.getElementById('text').style.display = 'none';
        }
    }
</script>

<form name="form">
<input name="choice" type="radio" onclick="DisplayElement(1)" checked/>
<input name="choice" type="radio" onclick="DisplayElement(2)"/>
<input name="text" type="text" id="text"/>
</form>

 
And here’s an even more flexible version. In this example you can pass the id of the element you want to hide as a second argument to the function. This way you can use the same function to toggle the visibility of many different elements.

<script type="text/javascript">
    function DisplayElement(x,target)
    {
        if (x == 1) {
            document.getElementById(target).style.display = '';
        }
        else {
            document.getElementById(target).style.display = 'none';
        }
    }
</script>

<form name="form">
<input name="choice" type="radio" onclick="DisplayElement(1,'text')" checked/>
<input name="choice" type="radio" onclick="DisplayElement(2,'text')"/>
<input name="text" type="text" id="text"/>
</form>

Here is another post, to do the same thing with a checkbox.

May 072012
 

This is a slightly edited version of this post. Just to make it work with a checkbox instead of radio buttons.

 

 

<html>
<head>
<script type="text/javascript">	
	function DisplayElement(checked) 
	{
		if (checked) {
			document.getElementById('text').style.display = '';
		}
		else {
			document.getElementById('text').style.display = 'none';
		}
	}
</script>
</head>
<body>
<form name="form">
<input type="checkbox" onclick="DisplayElement(this.checked)" checked/>
<input type="text" id="text"/>
</form>
</body>
</html>