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lib/Alien/GvaScript/AutoCompleter.pod  view on Meta::CPAN

=head1 SYNOPSIS

In Javascript :

  var autocompleter1 = new GvaScript.Autocompleter(
      "http::/some/url", 
      {minimumChars : 2, 
       strict       : true, 
       onBind       : doSomething,
       onLeave      : doSomethingElse}  );

  var autoCompleter2 = new GvaScript.Autocompleter(
        ["foo", "bar", ...], options);

  var autoCompleter3 = new GvaScript.Autocompleter(
        [{label: "foo", value: "f", otherValue: 123},
         {label: "bar", value: "b", otherValue: 456}, ...], options);

  var autoCompleter4 = new GvaScript.Autocompleter(
        myCompletionFunction, options);


Then, in HTML :

  <input onfocus="autoCompleter1.autocomplete(this)">


=head1 DESCRIPTION

Component designed both as an "autocompleter" (anticipating
further key events by users) and as a replacement for HTML C<SELECT>
form items.

An autocompleter instance encapsulates a datasource (which may be an
inline object, a callback function or an Ajax request), together with
some behavioral options (detailed below).  That autocompleter may then
be I<bound> to one or several input fields in a form (but only one at
a time), and will take care of capturing user input, navigating in the
suggestion list, and filling the field with the chosen value.

An event model is associated with the autocompleter, so that
client code can insert hooks to various steps of
the autocompletion behaviour.

The list of suggestions may contain arbitrary HTML, including rich
formatting options.


=head1 BEHAVIOUR

When the input field gets focus, the autocompleter starts listening
for key events. As soon as C<minimumChars> have been typed, or if the
user presses the C<DOWN> arrow key, the autocompleter gets a list of
suggestions from the datasource, and displays them in a dropdown list.

The dropdown list can be navigated through arrow keys. Selecting a
suggestion in the list is done either by a click, or by pressing the
C<RETURN> key (this is handled by the
L<Alien::GvaScript::ChoiceList|choiceList> component of
GvaScript). Then the value of that suggestion fills the input field
value, dependent fields (if any) are updated, and the C<onLegalValue>
event is triggered.

A number of variations on this behaviour may be controlled by the options
described below.


=head1 CONSTRUCTOR

  var myAutocompleter = new GvaScript.Autocompleter(datasource, options);

=head2 Datasources

=head3 Origin

A datasource may be

=over

=item a plain string

The string is taken as a base URL. Whenever a suggestion list is needed,
the autocompleter will send an Ajax requests to that URL, concatenated with 
the current value in the associated field. So for example if we have

  var ac = new GvaScript.Autocompleter("/myapp/completion?search=");
  ..
  <input name="someInput" onfocus="ac.complete(this)">

and user has typed C<ab> in the input field, then an Ajax request
will be sent to C</myapp/completion?search=ab>.

The server should return a JSON array, in the format explained below.

=item a callback function

That function will be called, with the current value of the field
as single argument.

=item an array

The array is taken as in-memory datasource. The returned suggestion
list is either the complete array (when C<options.ignorePrefix> is true)
or just the list of items that are prefixed by the current value 
of the field. See also C<options.caseSensitive>.

=item an object (JSONP)

Useful when accessing data on a different domain via JSONP services.

  Ex :   { json_url: 'http://search.yahooapis.com/WebSearchService/V1/relatedSuggestion?appid=YahooDemo&query=?1&output=json&callback=?2',
           json_list: 'ResultSet/Result' }

The object should hold details of the JSONP service to be called. 

C<json_url> : url to call with placeholders (?1, ?2) for value to look for and callback method respectively.

C<json_list> : path to the list in the json response

=back

lib/Alien/GvaScript/AutoCompleter.pod  view on Meta::CPAN

Default is 5

=item htmlWrapper

See the C<ChoiceList> documentation.

=item choiceItemTagName

See the C<ChoiceList> documentation.

=item classes

Classes that will be assigned at various stages
to autocompleter DOM elements .
Possible classes are 

=over 


=item loading

Class added to the  input or textarea field while an Ajax
request is pending. Default is C<AC_loading>, a class that displays
an Ajax-loading icon.

=item dropdown

Class for the dropdown div that displays the autocompletion choices.
Default is C<AC_dropdown>.

=item message

Class for displaying warning messages.
Default is C<AC_message>.


=back


=item additional_params

Other parameters to be added in the Ajax query for autocompletion.
Can be either an array or an already encoded string (see C<Ajax.Options> in
C<prototype.js>).
[TODO: should be camelCase to be consistent with other options; 
check dependencies in DMWeb].


=item dependentFields

  var ac =  new GvaScript.Autocompleter(url, {
              dependentFields : {
                foo : "firstname",
                bar : "lastname",
                id  : "id"
              } } );

Inline object that specifies dependencies between the field
controlled by the autocompleter, and other fields in the same form.
When leaving the autocompleted field (C<onBlur>), the dependent fields
will be updated automatically. This only works for autocompleters
in strict mode.

Each key in the inline object specifies the name of a field related
to the autocompleted field. If field names are in dotted notation, 
then the related field is taken as a path relative to the autocompleted
field : so for example if the autocompleted field has name
C<some.very.3.long.2.path>, then the C<foo> entry in
C<dependentFields> will refer to field C<some.very.3.long.2.foo>.


The corresponding value (in our example above: C<firstname>) is
the name of a property to extract from the C<choice> member
that validated the current input. However, the autocompleted field
may also contain an empty value (in which case the related fields
are also emptied), or an illegal value (in which case the related
fields are filled with string C<ILLEGAL_***>, where C<***> is the 
key from the inline object).

If the C<choice> member is not an object, but just a string,
then that string is copied to the dependent field, therefore ignoring
the hash value (C<firstname> in our example).

As a special case, if the hash value is an empty string,
then the dependent field is emptied, ignoring whatever
information may be in the C<choice> element.


The dependent fields structure might also be specified as
an HTML attribute C<ac:dependentFields>, instead of an option 
to the Javascript object :

  <input name="some.very.3.long.2.path"
         onfocus="ac.autocomplete(this)"
         ac:dependentFields="{foo:'firstname',bar:'lastname',id:'id'}" />
  ...
  <input type="hidden"
         name="some.very.3.long.2.id" />



=back

=head1 METHODS

=head2 autocomplete(inputField)

Returns an event handler to be bound to the C<onfocus> event on
an input field, i.e.

  <input name="someInput" onfocus="myAutoCompleter.complete(this)">

The autocompleter will automatically register 
C<onblur>, C<onclick> and C<onkeydown> handlers on the same field, so avoid
setting your own, which may cause unpredictable interactions.
However the autocompleter has its own event model 
to which you can bind your handling code
(see the L<EVENTS> section below).

=head2 detach(inputField)