S-controls, button on-click Javascript, and Visualforce pages can contain merge fields, which SFDC replaces with their record values prior to rendering. But this is a straight replacement, without any opportunity to escape characters. This leads to messy results when a merge field contains a double-quote character.
For example, consider using this merge field in on-click Javascript:
project.Name = "{!Opportunity.Name}";
That would work great, but consider what happens if the opportunity is named Acme "World Peace" Project (with the double quotes). SFDC will render the code as:
project.Name = "Acme "World Peace" Project";
Okay, now you have a huge mess. This will break the Javascript. A very clever workaround for this was created by an Appirio colleague of mine, Linda Evans. Here it is:
Step 1: Wrap the value in a hidden textarea.
Step 2: Retrieve the value by traversing the DOM.
So in our example above, first, you'd drop this HTML element into your page:
<textarea id="opportunityName" style="display:none">{!Opportunity.Name}</textarea>
Then, inside a <script> element, you'd retrieve the value:
project.Name = document.getElementById("opportunityName").value;
I told you this was clever - thanks Linda!
One final note, this won't work (directly) in a button on-click Javascript, since you can't put HTML elements in them (the entire body is considered a <script>). So you'll have to move your code into an s-control, and then tie your button instead to the s-control.
