Custom Server-Side Validator Element
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1 Custom Server-Side Validator - #custom {}
Attach a custom validator, written in Erlang, to an element. The validator will be executed on the server during a postback.
Usage
% Function to validate that a value is either upper or lower case, % depending on the value of Tag... F = fun(Tag, Value) -> case Tag of upper -> string:to_upper(Value) == Value; lower -> string:to_upper(Value) == Value end end, % Wire the validator in upper case mode... wf:wire(ButtonID, TextBoxID, #validate { validators=[ #custom { text="Must be uppercase", function=F, tag=upper } ]})
Attributes
- text - (string)
- The text to display if validation fails.
- function - (fun)
- An Erlang function that returns true if the value is valid, false if invalid. <br>fun(Tag, Value) -> 'true' or 'false'
- tag - (Erlang term)
- Tag value is passed into the custom validation function.