Hi Oleg,
So using document extensions to do what you're saying is definitely possible, especially the first two items you listed. In general, by the time you see a QliKView sheet in the AJAX client it's just a website. Because of that, most of the things you do using javascript and CSS in a regular site are possible here.
You've actually spurred me on to finally put my front end doc extension demo out on community:
http://community.qlik.com/docs/DOC-4243
I've been showing it for a while in my presentations as a sort of fun way to show how much you can mess with the UI from a doc extension. It's not well documented (which is why I never made it available), but the code could offer some insight to how to best approach your situation.
Some highlights/lessons learned:
- A document extension runs when the page is first loaded, it does not wait until all of the element on the page are rendered. So if you put code in that is trying to target or change an HTML element, it may not even be able to find that element yet. Due to this, you should use this code, which fires off a function after the page has loaded: this.Document.SetOnUpdateComplete(someFunction);
- Adding the CSS sheet is easy (see the extension I pointed to) but navigating your way through all of the HTML code to target/style the proper elements can be difficult. It takes some patience and some trickery but you can usually get to the objects pretty well. What you MUST get is the FireBug extension found here: http://community.qlik.com/thread/66688 By far the most useful tool there is in extension development. It lets you see the actual HTML code and even modify the CSS on the fly while seeing the page update.
- QlikView 11 has jQuery built into it. Use it. It makes this kind of thing so much easier.
To address your 3 scenarios directly...
- Removing and hiding elements on a screen is easy. Targeting them, like I said earlier, may not be. In fact a lot of things weren't possible before because there was no sensible way to target, in javascript, one listbox over another for example. The good news is that in v11 SR2 some code was added which adds a class to each object with its QlikView ID in it. GET THE FIREBUG EXTENSION. So, for example, if you have a chart with the ID of CH08, the class of the div would be "Document_CH08." Now that this object has a class that identifies it, we could easily hide it using jQuery by simply doing: $(".Document_CH08").hide()
- This could also be done, but I'm not saying it's going to be easy. You'd have to target the element you're looking to put the new element near and find out its position on the page. Then you could calculate where to place the new element nearby. I'm not sure how QlikView would react though as you switch between sheets and that kind of thing.
- Yikes. So as I think about it...yes, this is probably possible, but it'd be getting a little crazy and have a lot more potential for some major hurdles. You'd pretty much have to go rogue through a series of AJAX calls to the server...or something. I'm not sure. It might be possible it might not. It would be if you were willing to modify the actual base code of the product itself which would make your product no longer supportable.
Okay, so that's probably way more than you needed, but I thought it might be helpful to get all those tips out there.
Let me know if you have any more questions.
😞