Package play.mvc

Interface QueryStringBindable<T extends QueryStringBindable<T>>

public interface QueryStringBindable<T extends QueryStringBindable<T>>
Binder for query string parameters.

Any type T that implements this class can be bound to/from query one or more query string parameters. The only requirement is that the class provides a noarg constructor.

For example, the following type could be used to encode pagination: 

 class Pager implements QueryStringBindable<Pager> {
     public int index;
     public int size;

     public Optional<Pager> bind(String key, Map<String, String[]> data) {
         if (data.contains(key + ".index" && data.contains(key + ".size") {
             try {
                 index = Integer.parseInt(data.get(key + ".index")[0]);
                 size = Integer.parseInt(data.get(key + ".size")[0]);
                 return Optional.<Pager>ofNullable(this);
             } catch (NumberFormatException e) {
                 return Optional.<Pager>empty();
             }
         } else {
             return Optional.<Pager>empty();
         }
     }

     public String unbind(String key) {
         return key + ".index=" + index + "&" + key + ".size=" + size;
     }

     public String javascriptUnbind() {
         return "function(k,v) {\n" +
             "    return encodeURIComponent(k+'.index')+'='+v.index+'&'+encodeURIComponent(k+'.size')+'='+v.size;\n" +
             "}";
     }
 }
Then, to match the URL /foo?p.index=5&p.size=42, you could define the following route: 
 GET  /foo     controllers.Application.foo(p: Pager)
Of course, you could ignore the p key specified in the routes file and just use hard coded index and size parameters if you pleased.

  • Method Details

    • bind

      Optional<T> bind(String key, Map<String,String[]> data)
      Bind a query string parameter.
      Parameters:
      key - Parameter key
      data - The query string data
      Returns:
      An instance of this class (it could be this class) if the query string data can be bound to this type, or None if it couldn't.

    • unbind

      String unbind(String key)
      Unbind a query string parameter. This should return a query string fragment, in the form key=value[&key2=value2...].
      Parameters:
      key - Parameter key
      Returns:
      this key's query-string fragment.

    • javascriptUnbind

      String javascriptUnbind()
      Javascript function to unbind in the Javascript router.

      If this bindable just represents a single value, you may return null to let the default implementation handle it.

      Returns:
      null for default behavior, otherwise a valid javascript function that accepts the key and value as arguments and returns a valid query string fragment (in the format key=value)