Package org.apache.tapestry5.annotations

# Annotation Type RequestParameter

@Target(PARAMETER) @Retention(RUNTIME) @Documented @UseWith({COMPONENT,MIXIN,PAGE}) public @interface RequestParameter
Annotation that may be placed on parameters of event handler methods. Annotated parameters will be extracted from the request, then converted to the type of the parameter. Such parameters are separate from ordinary context parameters (extracted from the Request path). Typically, this is used when client-side JavaScript adds a query parameter to a request to communicate some information from the client side to the server side. Individual fields may also be directly mapped to query parameters using the `ActivationRequestParameter` annotation.

Since:
  5.2.0
See Also:
  - `OnEventWorker`

- ## Required Element Summary

  Required Elements
  Modifier and Type
  Required Element
  Description
  `String`
  `value`
  The name of the query parameter to extract from the request.

- ## Optional Element Summary

  Optional Elements
  Modifier and Type
  Optional Element
  Description
  `boolean`
  `allowBlank`
  If false (the default), then an exception is thrown when the query parameter is read, if it is blank (null or an empty string).

- ## Element Details

  - ### value

    String value
    The name of the query parameter to extract from the request.

- - ### allowBlank

    boolean allowBlank
    If false (the default), then an exception is thrown when the query parameter is read, if it is blank (null or an empty string). If true, then blank values are allowed and will be passed through the appropriate `ValueEncoder` implementation.
    Default:
      false