select UI Component

Ben Tiedt — Tue, 19 Nov 2019 20:29:55 GMT

Current Revision posted to API Documentation by Ben Tiedt on 11/19/2019 20:29:55

jQuery.telligent.evolution.ui.components.select

[[ui JavaScript API Module|UI Component]] which re-renders select elements as [[glowDropDownList jQuery Plugin|glowDropDownList]] instances on desktop. On narrow devices, continues to render as a native select, to give the theme a chance to more preceisely theme the form field on desktop use. Re-rendered selects' values are still updated and available to interacted with. [[ui JavaScript API Module|Overrides can be provided]] at the theme level to present selects differently.

Example

Usage

// Re-renders the select as a glowDropDownList on the desktop, not on mobile
<select class="ui-select" id="mySelect">
    <option value="a">Option A</option>
    <option value="b">Option B</option>
    <option value="c">Option C</option>
    <option value="d">Option D</option>
</select>

// Returns the value of the select, even when re-rendered
var value = $('#mySelect').val();

A barebones UI component override which would result in not re-rendering select elements

$.telligent.evolution.ui.components.select = {
    setup: function() { },
    add: function(elm, options) {
        // do nothing when added instead of re-rendering
    }
};

Default Implementation

For reference purposes or as the basis for an override:

(function($, global){

var minWindowWidth = 570,
    minWidth = 150,
    measuredHeight = null,
    measuredBorderHeight = null;

function measure(elm) {
    if(measuredHeight)
        return;
    var testDiv = $('<span class="uiselect"><span>measure</span></span>').css({'display':'none'}).appendTo(elm.parent());
    measuredHeight = testDiv.height();
    measuredBorderHeight = parseInt(testDiv.css('border-top-width') || '0') + parseInt(testDiv.css('border-bottom-width') || '0');
    testDiv.remove();
}

$.telligent.evolution.ui.components.select = {
    setup: function() { },
    add: function(elm, options) {
        elm.removeClass('ui-select');
        measure(elm);

        if(elm.is('select') && $(window).width() > minWindowWidth) {
            // set the height of the expanded view to not have empty space
            var optionLength = elm.find('option').length;
            var expandedHeight = optionLength * measuredHeight;

            // set a reasonable default width
            var width = elm.width();
            if(width < minWidth)
                width = minWidth;

            // render
            elm.show().glowDropDownList({
                selectedItemWidth: width + 20,
                selectedItemHeight: measuredHeight,
                itemsWidth: width + 20,
                itemsHeight: expandedHeight + measuredBorderHeight + 4, // (glowDropDownList assumes to - 4 from height)
                buttonImageUrl: null,
                className: 'uiselect'
            });
        }
    }
};

})(jQuery, window);