Vaadin autocomplete addon

This addon introduces a component named AutocompleteField primarily intended to display a set of choices retrieved from a slow source (can be the database or some search API working over the network). Main points:

• Not Container based: you set a query listener that dinamically fetches choices, and you are called back when the user selects one
• Users can still type their own query and you can read it via getText()
• Queries are not sent to the server side immediately, but only after the user has stopped typing (the timeout is configurable). You can also configure the minimum query characters count (default is 3), and the query is trimmed by default

Both the API and the implementation are in the early development stages and must be considered experimental. Suggestions are welcomed. At the moment, here is how the API looks like:

AutocompleteField<WikipediaPage> search = new AutocompleteField<>();

search.setQueryListener(new AutocompleteQueryListener<WikipediaPage>() {
  @Override
  public void handleUserQuery(AutocompleteField<WikipediaPage> field, String query) {
    for (WikipediaPage page : queryWikipediaApi(query)) {
      field.addSuggestion(page, page.getTitle());
    }
  }
});

search.setSuggestionPickedListener(new AutocompleteSuggestionPickedListener<WikipediaPage>() {
  @Override
  public void onSuggestionPicked(WikipediaPage page) {
    handleSuggestionSelection(page);
  }
});

At the moment I didn't find a good way to integrate with the Property API, mainly because the component can be used for two distinct purposes:

1. Entering text, possibly assisted by server suggestions
2. Selecting an item

It seems the best way would be exposing two server side components.

The code is organized in two directories (Maven projects):

• autocomplete contains the code for the Autocomplete addon
• demo is the test application to exercise the Autocomplete API

As long as the addon is not released on Maven central, it must be installed locally to satisfy the dependency of the demo application:

# In autocomplete
mvn clean install

Then one can start the demo with the following commands in the demo directory and then visit http://localhost:8080/app :

# Compiles the widgetset. Only needed the first time
mvn clean
mvn package
mvn jetty:run

To develop you may also want to run the GWT code server:

mvn vaadin:run-codeserver

Developers here

To start the development UI in the autocomplete directory:

# If widgetset needs to be recompiled
mvn clean package 
mvn jetty:run
# in another console, when you have to develop client-side things
mvn vaadin:run-codeserver

There are currently two UIs:

• DemoUI, which is intended to be put online as the live demo of this component. It's deployed at http://localhost:8080/app
• DevUI, which is for testing deployed at http://localhost:8080

Deploy

To release the artifacts to the Central repository

$ mvn clean deploy -P release

Credits

Thanks to Jeff T. Thorson jtt@thorson.net for his patches