Knockoutjs.com - Better list example

http://knockoutjs.com/examples/betterList.html

by zoldello

HTML

<script src="http://knockoutjs.com/downloads/knockout-3.0.0.js"></script>
<div class='liveExample'> 
    
    <form data-bind="submit:addItem">
        Add item: <input type="text" data-bind='value:itemToAdd, valueUpdate: "afterkeydown"' />
        <button type="submit" data-bind="enable: itemToAdd().length > 0">Add</button>
    </form>
     
    <p>Your values:</p>
    <select multiple="multiple" height="5" data-bind="options:allItems, selectedOptions:selectedItems"> </select>
     
    <div>
        <button data-bind="click: removeSelected, enable: selectedItems().length > 0">Remove</button>
        <button data-bind="click: sortItems, enable: allItems().length > 1">Sort</button>
    </div>
    
</div>

CSS

body { font-family: arial; font-size: 14px; }
.liveExample { padding: 1em; background-color: #EEEEDD; border: 1px solid #CCC; max-width: 655px; }
.liveExample input { font-family: Arial; }
.liveExample b { font-weight: bold; }
.liveExample p { margin-top: 0.9em; margin-bottom: 0.9em; }
.liveExample select[multiple] { width: 100%; height: 8em; }
.liveExample h2 { margin-top: 0.4em; }

JavaScript

var BetterListModel = function () {
    this.itemToAdd = ko.observable("");
    this.allItems = ko.observableArray(["Fries", "Eggs Benedict", "Ham", "Cheese"]); // Initial items
    this.selectedItems = ko.observableArray(["Ham"]);                                // Initial selection
 
    this.addItem = function () {
        if ((this.itemToAdd() != "") && (this.allItems.indexOf(this.itemToAdd()) < 0)) // Prevent blanks and duplicates
            this.allItems.push(this.itemToAdd());
        this.itemToAdd(""); // Clear the text box
    };
 
    this.removeSelected = function () {
        this.allItems.removeAll(this.selectedItems());
        this.selectedItems([]); // Clear selection
    };
 
    this.sortItems = function() {
        this.allItems.sort();
    };
};
 
ko.applyBindings(new BetterListModel());