使用Javascript切换CSS值

Question

I'm trying to modify the behavior of some web parts in Sharepoint (thus forcing IE down my throat) for our users who use the Project server pages. I'm not really the best JavaScript guy, and this is driving me nuts.

On one webpart to display the work from Project, there is a subrow 'Planned' shown below the actual data entry row that clutters the view. We want to turn the 'Planned' row off.

I can do it with a simple three liner like this:

<style type="text/css">
   .XmlGridPlannedWork {display:none;}
</style>

But the users want to toggle the lines on and off. So I thought I'd try reading then writting the current CSS value like so:

<script type="text/javascript">

function toggle_PlannedLine()
var ObjPlanned = Document.getElementById("tr").getElementsByTagName("XmlGridPlannedWork");

for(var i=0;i<ObjPlanned.length;i++)
{
    if (OjbPlanned[i].display != "none")
    {
        // toggle the 'Planned' line off
        ObjPlanned[i].style.display = "none";
    }
    else
    {
        // toggle the 'Planned' line on
        ObjPlanned[i].style.display = "inline";
    }
}

return;
}

</script>

<button onClick="toggle_PlannedLine();">Toggle Planned Line</button>

The actual segment I'm targeting looks like this:

<tr class="XmlGridPlannedWork" RowID="694810f9-e922-4321-9236-e495dd5048d9B" ID="GridDataRow">

Of course, when you click the button, the rows don't disappear. At this point, I'm pretty sure I'm missing something obvious, but like I mentioned, I'm no JavaScript guru.

Answer 1

Easiest Solution

Ok, so my answer below should help you out, but here is another way to approach it that is much simpler:

CSS

<style type="text/css">
   .XmlGridPlannedWork {display:none;}
   body.showPlanned .XmlGridPlannedWork { display: block}
</style>

HTML/JavaScript

<script type="text/javascript">
function toggle_PlannedLine() {
    if(document.body.className.match(/\bshowPlanned\b/) > -1)
        document.body.className = document.body.className.replace(/\bshowPlanned\b/,'');
    else
        document.body.className += " showPlanned";
}
</script>

<button onClick="toggle_PlannedLine();">Toggle Planned Line</button>

Original Answer

You were really close in the concepts you wanted, but as the other answers point out a number of things were missing. I rewrote your function to work cross browser, and please ask if you have any questions about it:

<script type="text/javascript">

function toggle_PlannedLine() {
  var objs = [];

  if( document.querySelector){
     objs = document.querySelectorAll('tr.XmlGridPlannedWork');
  } else if (document.getElementsByClassName) {
     objs = document.getElementsByClassName('XmlGridPlannedWork');
  } else {
     var temp = document.getElementsByTagName('tr');
     for(var j = 0; j < temp.length; j++){
       if(temp[j].className.match(/\bXmlGridPlannedWork\b/) > -1){
         objs.push(temp[j]);
       }
     }
  }

  for(var i=0;i<objs.length;i++)
  {
      if (objs[i].style.display != "none")
      {
          // toggle the 'Planned' line off
          objs[i].style.display = "none";
      }
      else
      {
          // toggle the 'Planned' line on
          objs[i].style.display = "inline";
      }
  }
}

</script>

<button onClick="toggle_PlannedLine();">Toggle Planned Line</button>

For those arguing that jQuery is not a valid answer, please take the following code as an example of why jQuery is so easy to use. All of the previous code is summed up like this:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script type="text/javascript" charset="utf-8">
  $(function(){
    $('button.toggle').click(function(){
      $("tr.XmlGridPlannedWork").toggle();
    })
  })
</script>

<button class="toggle">Toggle Planned Line</button>

Answer 2

You forgot the opening brace for your function.

You are using getElementByTagName incorrectly. This function gets elements that match based on tag name (a, img, etc.) not CSS class. You can use jquery to accomplish what you want, or you can enumerate through every element on the page until you find the one you want. There are some open-source implementations of this available online. Your best bet, though, would be to add an id to the tag you care about, and then use getElementById .

Finally, Document should be document , and JavaScript is case sensitive.

Hope this helps!

Answer 3

document.getElementsByTagName looks for elements based on the name of their HTML tag, not their class attribute. Newer (not IE) browsers have support for document.getElementsByClassName(), and there are open source functions that do the same thing, falling back on the browser-native versions where available. This function will return a NodeList containing all the elements that use that class, and you can access each element and hide it through that list.

Answer 4

First, document should be lowercase in your var ObjPlanned declaration. Second, getElementById returns an element based on a unique ID and you're passing it the element, or tag, name. getElementsByTagName returns an array of elements matching a certain tag but you're passing it a className. There is no 'getElementsByClassName' built in to JavaScript, but you can easily use Google to find a solution.

Answer 5

Use jQuery . It provides a very useful $.css() method, which does what you're looking for in a very simple fashion.