Custom Server Side Data Validation

To do this, use Ajax call to server side validation script in custom data validation method set_col_customrule(). Please see 
http://phpgrid.com/example/custom-data-validation/

For direct server side error response, please see:
http://phpgrid.uservoice.com/knowledgebase/articles/325894

For development purpose, you can also view the server side error by turning on the DEBUG flag in conf.php. Please see http://phpgrid.com/documentation/debug/

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