Efficiently combine Paging and Filtering

[James]

For filtering we are using the kendo data query "process" library.  The issue is that when you combine this with paging, there are issues with determining the total number of items since "process" returns an array only of your page size. 

So I essentially have to run "process" twice:

1.  So I can get the filtered and paged data

2.  Again with just the filter parameters so I can get how many total items are in the set after filters have been applied

 

For example:

loadItems() {
    const myData: any = []; //Some data in here
    let gs: State = {
      skip: 0,
      take: 10,
      filter: {
        //Some filter data
      } as CompositeFilterDescriptor
    };
    //THis will filter my data, then return the paged slice of it
    let gd: GridDataResult = process(myData, gs);
    //This will run just the filter so I can get the total items
    gd.total = process(myData, {filter: gs.filter} as State).data.length;
  }

Is there a better way to get the total number of filtered items when I am also using paging instead of having to run "process" twice?  I have thought about extending the "process" so I can add an extra field on it with total entries but not sure how to get started. 

Any assistance would be appreciated.

[Svet]

Hi James,

Thank you for the provided details.

In general the process() method accepts one parameter of type array and a second one of type State and returns an object of type DataResult. The State parameter can contain info for the paging and for the current Grid filters. The info for the paging should be passed with the skip and take properties, while the info for the applied filters should be passed in the filter property. The returned value by the function is of type DataResult which provides an array of the processed data items in the data property (that is the current data that will be displayed by the Grid) and the total number of items (these are he total number of records that are available not just the number of the items in the data property) in the total property.

To sum up, running the process() method once can process the passed data as per the passed paging and filtering details and returns the processed data and the total number of items that were initially passed for processing to the function.

I hope this helps.

Regards,
Svet
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