Twitter bootstrap collapse: change display of toggle button

I am using Twitter Bootstrap to create collapsible sections of text. The sections are expanded when a + button is pressed. My html code as follows:

<div class="row-fluid summary">
    <div class="span11">
        <h2>MyHeading</h2>  
    </div>
    <div class="span1">
        <button type="button" class="btn btn-success" data-toggle="collapse" data-target="#intro">+</button>
    </div>
</div>
<div class="row-fluid summary">
    <div id="intro" class="collapse"> 
        Here comes the text...
    </div>
</div>

Is there a way to change the button to display - instead of + after the section is expanded (and change back to + when it is collapsed again)?

Additional information: I hoped there would be a simple twitter-bootstrap/css/html-based solution to my problem. All responses so far make use of JavaScript or PHP. Because of this I want to add some more information about my development environment: I want to use this solution inside a SilverStripe-based (version 3.0.5) website which has some implications for the use of both PHP as well as JavaScript.

Solution 1:

try this. http://jsfiddle.net/fVpkm/

Html:-

<div class="row-fluid summary">
    <div class="span11">
        <h2>MyHeading</h2>  
    </div>
    <div class="span1">
        <button class="btn btn-success" data-toggle="collapse" data-target="#intro">+</button>
    </div>
</div>
<div class="row-fluid summary">
    <div id="intro" class="collapse"> 
        Here comes the text...
    </div>
</div>

JS:-

$('button').click(function(){ //you can give id or class name here for $('button')
    $(this).text(function(i,old){
        return old=='+' ?  '-' : '+';
    });
});

Update With pure Css, pseudo elements

http://jsfiddle.net/r4Bdz/

Supported Browsers

button.btn.collapsed:before
{
    content:'+' ;
    display:block;
    width:15px;
}
button.btn:before
{
    content:'-' ;
    display:block;
    width:15px;
}

Update 2 With pure Javascript

http://jsfiddle.net/WteTy/

function handleClick()
{
    this.value = (this.value == '+' ? '-' : '+');
}
document.getElementById('collapsible').onclick=handleClick;

Solution 2:

Here's another CSS only solution that works with any HTML layout.

It works with any element you need to switch. Whatever your toggle layout is you just put it inside a couple of elements with the if-collapsed and if-not-collapsed classes inside the toggle element.

The only catch is that you have to make sure you put the desired initial state of the toggle. If it's initially closed, then put a collapsed class on the toggle.

It also requires the :not selector, so it doesn't work on IE8.

HTML example:

<a class="btn btn-primary collapsed" data-toggle="collapse" href="#collapseExample">
  <!--You can put any valid html inside these!-->
  <span class="if-collapsed">Open</span>
  <span class="if-not-collapsed">Close</span>
</a>
<div class="collapse" id="collapseExample">
  <div class="well">
    ...
  </div>
</div>

Less version:

[data-toggle="collapse"] {
    &.collapsed .if-not-collapsed {
         display: none;
    }
    &:not(.collapsed) .if-collapsed {
         display: none;
    }
}

CSS version:

[data-toggle="collapse"].collapsed .if-not-collapsed {
  display: none;
}
[data-toggle="collapse"]:not(.collapsed) .if-collapsed {
  display: none;
}

JS Fiddle

Solution 3:

Add some jquery code, you need jquery to do this :

<script>
        $(".btn[data-toggle='collapse']").click(function() {
            if ($(this).text() == '+') {
                $(this).text('-');
            } else {
                $(this).text('+');
            }
        });
        </script>