jQuery UI autocomplete combo box issue

I'm trying to use this example http://jqueryui.com/demos/autocomplete/#combobox . But it shows blank option by default. instead of "Select one...". How to fix that problem?

And one more question: I don't use "show underlying menu" 开发者_运维知识库buton as in show in example. Is there any unused pc of code for that button in JS code?

it shows blank option by default. instead of "Select one...". How to fix that problem?

The reason this is occurring is this piece of code in the _create function:

value = selected.val() ? selected.text() : "";

Just change the false portion of the ternary to say "Select One":

value = selected.val() ? selected.text() : "Select one...";

Here's the modified widget for reference:

$.widget( "ui.combobox", {
    _create: function() {
        var self = this,
            select = this.element.hide(),
            selected = select.children( ":selected" ),
            value = selected.val() ? selected.text() : "Select One...";
        var input = this.input = $( "<input>" )
            .insertAfter( select )
            .val( value )
            .autocomplete({
                delay: 0,
                minLength: 0,
                source: function( request, response ) {
                    var matcher = new RegExp( $.ui.autocomplete.escapeRegex(request.term), "i" );
                    response( select.children( "option" ).map(function() {
                        var text = $( this ).text();
                        if ( this.value && ( !request.term || matcher.test(text) ) )
                            return {
                                label: text.replace(
                                    new RegExp(
                                        "(?![^&;]+;)(?!<[^<>]*)(" +
                                        $.ui.autocomplete.escapeRegex(request.term) +
                                        ")(?![^<>]*>)(?![^&;]+;)", "gi"
                                    ), "<strong>$1</strong>" ),
                                value: text,
                                option: this
                            };
                    }) );
                },
                select: function( event, ui ) {
                    ui.item.option.selected = true;
                    self._trigger( "selected", event, {
                        item: ui.item.option
                    });
                },
                change: function( event, ui ) {
                    if ( !ui.item ) {
                        var matcher = new RegExp( "^" + $.ui.autocomplete.escapeRegex( $(this).val() ) + "$", "i" ),
                            valid = false;
                        select.children( "option" ).each(function() {
                            if ( $( this ).text().match( matcher ) ) {
                                this.selected = valid = true;
                                return false;
                            }
                        });
                        if ( !valid ) {
                            $( this ).val( "" );
                            select.val( "" );
                            input.data( "autocomplete" ).term = "";
                            return false;
                        }
                    }
                }
            })
            .addClass( "ui-widget ui-widget-content ui-corner-left" );

        input.data( "autocomplete" )._renderItem = function( ul, item ) {
            return $( "<li></li>" )
                .data( "item.autocomplete", item )
                .append( "<a>" + item.label + "</a>" )
                .appendTo( ul );
        };

        this.button = $( "<button type='button'>&nbsp;</button>" )
            .attr( "tabIndex", -1 )
            .attr( "title", "Show All Items" )
            .insertAfter( input )
            .button({
                icons: {
                    primary: "ui-icon-triangle-1-s"
                },
                text: false
            })
            .removeClass( "ui-corner-all" )
            .addClass( "ui-corner-right ui-button-icon" )
            .click(function() {
                if ( input.autocomplete( "widget" ).is( ":visible" ) ) {
                    input.autocomplete( "close" );
                    return;
                }

                $( this ).blur();
                input.autocomplete( "search", "" );
                input.focus();
            });
    },

    destroy: function() {
        this.input.remove();
        this.button.remove();
        this.element.show();
        $.Widget.prototype.destroy.call( this );
    }
});

I don't use "show underlying menu" buton as in show in example. Is there any unused pc of code for that button in JS code?

Yes, you're safe to remove that button. In fact, all you need is a select element to initialize the widget on.

Here's an example of the combobox without a button and with "Select one..." as the default text: http://jsfiddle.net/andrewwhitaker/MgjRy/