list control woes

[frankbicknell]

I have a ux that has a list control. The list control is set to return the primary key of the fields from a mysql table. I would like to prevent a user from selecting certain items in the list control using the OnBeforeSelect Event. The only way I can figure on how to make it work the way I want is with an ajaxcallback in the OnBeforeSelect event. The problem is that the e._currentRowDataNew.listname object in the callback does not contain the key field value.
Am I doing something wrong? Is this a bug? I know it is the OnBeforeSelect event but it should contain the key value otherwise how can you determine what list items can be selected or not?

[Davidk]

Re: list control woes

I think you're misunderstanding what onBeforeSelect does. It does not test the value of the item you ARE selecting. onBeforeSelect fires before the select is done so that you can determine if anything else can be selected.

E.g. If you only allow 2 selections, onBeforeSelect will know that and you can return false to prevent any further selections.

You're thinking that onBeforeSelect will test the selection you just made and allow you to prevent that current selection... but it doesn't work like that.

Is this a Single or Multi Select List Control? Do you allow nulls or not in the list?

EDIT: The following info refers to a part of your post that you removed.
I think you're a little too quick to "call bug". If you read the notes for the various "select" events you'll see references to the List allowing, or not, nulls items. Some of the events get fired when the List gets initialized. You need to test if the List is initialized before trying to access controls in the List. Have a look at the notes for onSelect. Those notes reference code such as...

if (this.initialized) {
//then do your stuff
}

You can get at the Array of keys being selected and test that array for anything you do not want to allow. I think you may be able to reset that Array.

[frankbicknell]

Re: list control woes

Thanks David,

I agree I am misunderstanding what the OnBeforeSelect does. I also figured out that I was using the placeholders incorrectly that is why I removed that sentence.
I have figured out that I can get the key id in the onSelect event then do an ajax callback and do some sql mumbo jumbo and prevent the edit dialog from opening but it just seems so clunky and wrong. Plus the user has already selected the list item (wasting several seconds of time). I was hoping to just prevent the initial selection of the wrong time item.

Let me try to explain what I am doing.

This is a ux that contains service log data. It is opened from a list filtered by the id of the logged in tech
2014-05-11_13-22-48.png
When I click the time tab it opens another ux with the time data for the service log. When an item in the list is clicked it opens a dialog to edit the time record.
2014-05-11_14-11-30.png

I want the logged in, assigned tech to be able to see all of the time for the log but only be able to edit their own time.
I had this all working in a grid but recently discovered lists. They are so much better for this process than grids, however there is a big learning curve for me and I'm not getting it.

If you have any advice I would appreciate if you would share it with me.

[frankbicknell]

Re: list control woes

Actually the sql mumbo jumbo ended up being only one sql_lookup so that was not so bad. Still seems like I should be able to prevent the selection in the first place. I can't even get the conditional formatting to work to give a visual indication of right and wrong. These list controls are a challenge.

[Davidk]

Re: list control woes

Yes... this is very easy to do staying client-side since the List control gives us everything we need to test with.

You will need to get the assigned tech value into a client-side variable. Then you can use onSelect to test against that value. You don't need, nor should you need, to go back to the server for this.

It looks like you're using a single-select List Control... which is actually a bit easier to work with than a multi-select List control. Here's an example that shows how to work with both single and multi select.

http://www.youtube.com/watch?v=vYdFYJdwWzU

Code for multi-select List, onSelect event

if (this.initialized){
	
	currCountry = {dialog.Object}._currCountry;		
	var index = this.value.indexOf(currCountry);
	//if (index > -1) {		//found the item
	if (index == -1){			// did not fild the item
		alert('Thank you for selecting ' + this.value);
	} else {
		this.selectionKey.splice(index, 1);
		this.selection.splice(index, 1);
		this.value.splice(index, 1);
		this.selectionData.splice(index, 1);   
		var listObj = {dialog.object}.getControl('LIST1');
		listObj.refresh();
		alert('Sorry... you can select anything except ' + currCountry);
	}	

}

//	this.selectionKey					//List index zero based
//	this.value							//Data values e.g. Canada
//	this.selectionData				//Selection objects of data
//	this.selection						//List index zero based

Code for single-select List Control, onSelect event

if (this.initialized){

		currCountry = {dialog.Object}._currCountry;		
		if (this.value == currCountry){
			alert('This selection is ok');
		} else {
			alert('This selection is NOT ok');
		}
}

[frankbicknell]

Re: list control woes

Thank you David for taking the time to help and educate me. I will digest all of this then put it to use. Your way is far better than mine.

[Davidk]

Re: list control woes

The server is great... but if you can stay client-side, you get lightning speed. If you need data, then you've got to go get it. But, if you have the data, stay put and get things done really fast.