The message can also be a function which will be called to retrieve the message, besides this it is treated like a normal message (the attribute name is prepended etc).
If the message is not a function and not a string it is simply returned as is.
Sometimes it's nice to be able validate field differently depending on the input itself.
allows the validators object and validator options to be a function that should return the constraints/options: Validates the attributes object against the constraints.
Any A type promise can be used, just override function success(attributes) function error(errors) var constraints = ; var attributes = ; // Will call the success function and log validate.async(attributes, constraints).then(success, error); // Will call the error function validate.async(, constraints).then(success, error); function Validation Errors(errors, options, attributes, constraints) Validation Errors.prototype = new Error(); // This isn't supported by the ES6 promises validate.async(, constraints, ) .then(success) .catch(Validation Errors, function(error) ) .catch(function(error) ); // Supporting another promise implementation (RSVP in this case) validate. Promise; Sometimes you only want to validate a single value against some constraints and using the normal validate function is quite verbose so there is a shorthand for this.
It does little more than proxying the call to the main validation function but with the value wrapped in an object and the options full Messages and format set to also has limited support for nested objects (objects within objects) using the dot notation.
Unless otherwise specified you can always specify the message option to customize the message returned if the validator doesn't pass.