jQuery.validator.addMethod()

jQuery.validator.addMethod( name, method [, message ] )

Description: Add a custom validation method. It must consist of a name (must be a legal javascript identifier), a javascript based function and a default string message.

  • jQuery.validator.addMethod( name, method [, message ] )

    • name
      Type: String
      The name of the method used to identify it and referencing it; this must be a valid JavaScript identifier
    • method
      Type: Function()
      The actual method implementation, returning true if an element is valid. First argument: Current value. Second argument: Validated element. Third argument: Parameters.
      • value
        Type: String
        the current value of the validated element
      • element
        Type: Element
        the element to be validated
      • params
        Type: Object
        parameters specified for the method, e.g. for min: 5, the parameter is 5, for range: [1, 5] it's [1, 5]
    • message
      Type: String
      The default message to display for this method. Can be a function created by ''jQuery.validator.format(value)''. When undefined, an existing message is used (handy for localization), otherwise the field-specific messages have to be defined.
For simple one-off validation, you can use the bundled pattern method (in additional methods, source in src/additional/pattern.js) to validate a field against a regular expression. In general, it is a good idea to encapsulate those regular expressions inside their own method. If you need lots of slightly different expressions, try to extract a common parameter.

See also a library of regular expressions.

Examples:

Example: Add a validation method that checks if a value starts with a certain domain.

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jQuery.validator.addMethod("domain", function(value, element) {

  return this.optional(element) || /^http:\/\/mycorporatedomain.com/.test(value);

}, "Please specify the correct domain for your documents");

Example: Adds a validation method that checks if a given value equals the addition of the two parameters.

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jQuery.validator.addMethod("math", function(value, element, params) {

  return this.optional(element) || value == params[0] + params[1];

}, jQuery.validator.format("Please enter the correct value for {0} + {1}"));

Example: Adds a custom email validation method that is less strict than the one built-in.

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jQuery.validator.addMethod("laxEmail", function(value, element) {

  // allow any non-whitespace characters as the host part

  return this.optional( element ) || /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@(?:\S{1,63})$/.test( value );

}, 'Please enter a valid email address.');