Why are group descriptors, sort descriptors and filter descriptors are collections?

[Paulo Morgado]

I’ve been reading the documentation for RadJumpList and I can’t understand why group descriptors, sort descriptors and filter descriptors are collections.

 

All examples show collections with a single element. It would be nice to provide an example on how a collection with more than one element would be used.

[Vijay]

Hello Paulo

Collection are used here as set of objects that you can access by stepping through each element in turn. In RadJumpList the elements are arranged as in collective manner such that it can be filtered, sorted, grouped, define some headers or many more. Please Look into the below links which is explained much clearly.

Click here for Group Descriptors

Click here for Sort Descriptors

Click here for Filter Descriptors 

Thanks and Regards,
Vijay
MVC Corp.

[Paulo Morgado]

Hi Vijav,

The links that you provided (which I had read before) don not explain nor they exemplify why they are collections.

Let’s take the GroupDescritors (the others are pretty much the same).

The value of the GroupDescriptorsSource property (and the corresponding attached property GroupDescriptorsSourceProperty) is an enumerable of DataDescriptor instances and the value of the GroupDescriptors property is an observable collection of DataDescriptor instances.

But the code sample only shows its usage with a collection of only one descriptor.

So, my doubts remain:

1. Why is it a collection of descriptors instead of a single descriptor?
2. How would I use a collection with more than one descriptor?

[Deyan]

Hello Paulo,

The answer to your question is quite simple:

Imagine that you want to group the items in a given data group. So in this case you will have to insert one group descriptor to create the initial groups, and after that another group descriptor to create the sub-groups within each initial group. A simple real-life example would be a list of products that can be ordered in groups of categories and sub-categories after that.

The same is with filtering and sorting.

I hope this answers your question.

Let me know if I can assist you further.

Greetings,
Deyan
the Telerik team

[Paulo Morgado]

Thanks, Deyan. Now it all makes sense.

Wouldn't it be nice to show a usage of this on the documentation or a blog post? I think it would.

[Deyan]

Hi Paulo,

Thanks for getting back to me.

We will consider your suggestion.

Do not hesitate to get back to us anytime you have further questions or need assistance.

All the best,
Deyan
the Telerik team