com.databasesandlife.util.wicket
Class MultipleValueAutoSuggestTextField

java.lang.Object
  com.databasesandlife.util.wicket.MultipleValueAutoSuggestTextField

public class MultipleValueAutoSuggestTextField
extends Object

Represents a text-field in Wicket, which allows the user to enter multiple values, and values are suggested from a list of existing values. These values are only suggestions, however, the user may type in other new values, not in the list of existing values. This is ideal for entering tags on a newly created object, where you want the user to use existing tags if appropriate, but also allow the user to create new tags if none of the existing ones are appropriate.

If new values should not be allowed, for example when selecting from a list of existing languages, see MultipleValueAutoCompleteTextField.

The model of the field is an array of Strings which have been chosen. (It is not possible to display strings to the user, while maintaining a list of IDs corresponding to those strings internally, as the user may enter new strings, and those would have no corresponding IDs.)

The list of values to be suggested is a collection of Strings. There are two ways the these may be fetched:

• Client-side - Either all entries are given to the object as a String[], in which case they will be inserted into the HTML page. Suggestions are fast, as a server round-trip is not necessary. This is not practical if there are 1M entries, as the generated HTML will be too large.
• Server-side - Or a lookup function is provided which can take a substring and can return an ordered String[] of suggestions matching that substring, it is advised to return no more than 10 or 50 entries from this function, otherwise the HTTP communication will be too large. This requires a server round-trip each time the user types a character, so is less responsive.

Usage:

  <!-- in HTML -->
  <!-- Include JQuery, JQuery UI-->
  <link rel="stylesheet" type="text/css" ....> <-- From JQuery UI themeroller >
  <input type="text" wicket:id="tags" class="my-css-class"></input>

  // In Java
  MultipleValueAutoSuggestTextField tagsField =
      new MultipleValueAutoSuggestTextField("tags");
  tagsField.setClientSideOptions(new String[] { "java", "php" }); // or..
  tagsField.setServerSideDataSource(new AutoSuggestDataSource() {
      public String[] suggest(String userEnteredPartialText) {
          return new String[] { "java", "php" };
      }
  });
  form.add(tagsField);

If there is an error about a missing </span> tag, make sure the <input> tag is closed with a </input>, even though HTML would not normally require it to be closed. This is a consequence of an implementation issue.

The Javascript used by this software is based on the JQuery autocomplete multiple example.

Version:

$Revision: 3740 $

Author:

The Java source is copyright Adrian Smith and licensed under the LGPL 3.

Constructor Summary

MultipleValueAutoSuggestTextField()

Method Summary

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MultipleValueAutoSuggestTextField

public MultipleValueAutoSuggestTextField()