[Solved] Filtering for null or zero length string

[Andrew]

Is there anyway to allow the user to select a zero length string (or null) to filter against: so that they can find all the items which have not yet been filled in ? Seems like it should be simple, but I'm not finding a way to do that yet.

[Hristo Germanov]

Hi Andrew,

This functionality can be achieved using ComboBox component. It will send HTML input value (which will be empty string in this case) to the server. Hence you can return the required list of items. Look at this online example.

Sincerely yours,
Hristo Germanov
the Telerik team

[Andrew]

I'm after filtering in a grid view - I'd like (the user) to be able to filter for blank along side the other options. I understand how to use a drop down list to alter the result set returned from the server, but what you are suggesting involves turning filtering off for the grid view, then reimplementing it from scratch using extra controls which seems a pity.

[Georgi Krustev]

Hello Andrew,

By design grid does not filter on empty string, because when input is empty grid thinks that there is no applied filter. One possible workaround is to define text which represent empty string. For instance user can set "None" and to filter by this value. On the server you can get this "None" value and filter on empty string. For this goal you will need custom binding.

Kind regards,
Georgi Krustev
the Telerik team

[Andrew]

Thank you for your help. I'll give that a try

[Carson]

Instead of having to deal with custom binding for this very common scenario, it would be great if the filter options included 'Is Empty' and 'Is Not Empty'.

[Linas]

I totally agree with Carson: it should be possible for the user to simply filter the items which have not been filled in yet in the grid. Are there any plans to implement "Is Empty" filter operator?

[Ed]

A default filter of "is Blank" or "is not Blank" would be nice to have to go along with the standard:

"is equal to"
"is not equal to"
"Starts with"
"Contains" 
and
"Ends with"

of course Blank is different the null, so "is Null" and "is not Null" would be a great addition.

[Sid]

This should definitely be an included feature out of the box, not something you have to customize.  I know you've gone on to Kendo, is this going to be included at some point?

[Rajendra]

I think this will be a feature. Make sure you promote the feature by voting. Hopefully this will get included in some release sooner.

http://www.telerik.com/support/pits.aspx#/details/Issue=9213