Custom Filter Operators

[Phil]

It would be greatly beneficial to our projects if there were enhancements to the Filter component to allow for supplying custom Filter Operators. For example, our legacy software provided native "Between" operator support along with custom "Date Range" operators, such as "today", "Yesterday", "This Week", etc. While I wouldn't expect Telerik to support these out of the box, it would be great to be able to add our own operators/Filter types.

[Tsvetomir]

Hi, Phil,

Thank you for taking the time to share your feedback. Currently, the Filter component is intended to have only strongly-typed filter operator values, more specifically, the operator should be of type FilterOperator Enum. It comes with a set of predefined values for all built-in operators. If we were to expose an option to add a custom operator, it would break the strongly-typed orientation of the component.

Currently, we have a pending Feature Request in our feedback portal regarding the field template option of the Filter:

https://feedback.telerik.com/blazor/1561874-filter-field-template

Whenever it gets implemented, you will be able to declare two date pickers and built custom filter descriptors that will play the role of the "Between" operator. We have a similar example for the grid that filters a numeric field by a range between two numeric values (the Price column in the demo below):

https://demos.telerik.com/blazor-ui/grid/custom-filter-row

As an alternative, you can override one (or many) of the predefined operators and execute custom logic for the filtering. Check the following POC example:

https://blazorrepl.telerik.com/wGkzlilm34568tY852

I hope you find the information above helpful.

Kind regards,
Tsvetomir
Progress Telerik

[Víctor]

I would also like to extend the default filters.

Why not using a class hierarchy instead of an enum? This way we could add out own subclases.

I need my users to be able to have dropdowns for related entities.

[Tsvetomir]

I recommend sharing your opinion and feedback directly in the feature request's item so that whenever a developer starts working and researching, they'll implement it in such a way that is helpful for all:

https://feedback.telerik.com/blazor/1561874-filter-field-template