Add "allow_blank" option (default is "true", but it should be "false" IMHO)

[Oliboy50]

I needed this for my project, because it was completely useless to have a blank entry in my filter inputs.

[vedmack]

Looks very detailed :) , bummer you haven't done your modification on more recent version of yadcf (lab version - https://github.com/vedmack/yadcf/blob/master/lab/jquery.dataTables.yadcf.js)

Will inspect it later on...

[Oliboy50]

Oh, I didn't see this folder. Maybe the "select blank value issue" is already fixed there.

If it's not the case, this PR is as simple as checking if the column data is empty before adding it to the select input ( https://github.com/vedmack/yadcf/pull/112/files#diff-9ef1d6803d7184632df46a815b39de1eR1377 ).

And I'm sure that it would be better if it was the default behavior.
I don't think someone would need a blank value as filter.

Thanks for the plugin!

[vedmack]

Actually you are right, such feature better be a default behavior and it shouldn't even be an option to config, so if you want, you can open a new PR on the lab version for it (no documentation/configuration needed) , if not I guess I will add it myself.

[vedmack]

Shame to close this PR (appreciate the effort), but you are probably right, no need for empty values in the filter at all, so this PR is redundant, feel free to send PR for "hard coded" fix for this issue (on lab version js)