From ddae98d2336ece6191c1ae9290209182d867ab26 Mon Sep 17 00:00:00 2001
From: Peter Hrdlica <peter@binarity.cz>
Date: Sun, 15 Oct 2017 15:54:21 +0200
Subject: [PATCH] multiselect component

---
 .../multiselectcomponent.html                 |  46 +++++++
 .../multiselectcomponent.js                   | 121 ++++++++++++++++++
 2 files changed, 167 insertions(+)
 create mode 100644 public/custom/multiselectcomponent/multiselectcomponent.html
 create mode 100644 public/custom/multiselectcomponent/multiselectcomponent.js

diff --git a/public/custom/multiselectcomponent/multiselectcomponent.html b/public/custom/multiselectcomponent/multiselectcomponent.html
new file mode 100644
index 00000000..c49e3bff
--- /dev/null
+++ b/public/custom/multiselectcomponent/multiselectcomponent.html
@@ -0,0 +1,46 @@
+<html>
+<head>
+    <meta charset="utf-8">
+    <script src="multiselectcomponent.js"></script>
+</head>
+<body>
+    <div style="width: 50%; float: left;" id="left"></div>
+    <div style="width: 50%; float: right;" id="right"></div>
+
+    <script type="application/javascript">
+        // Sample data.
+        var data1 = [
+            {id: 1, name: 'Peter', surname: 'Hrdlica'},
+            {id: 6, name: 'Vojtěch', surname: 'Hrdlica'},
+            {id: 2, name: 'Michal', surname: 'Kváček'},
+            {id: 19, name: 'Miček', surname: 'Je kokot!'},
+            {id: 13, name: 'Mirek', surname: 'Mráček'},
+            {id: 11, name: 'Naděžda', surname: 'Zímová'}
+        ];
+
+        var data2 = [
+            {id: 2, name: 'wanna', surname: 'know'},
+            {id: 6, name: 'Batman', surname: 'insulted'},
+            {id: 58, name: 'scream', surname: 'pushed'},
+            {id: 19, name: 'Mob', surname: 'why'},
+            {id: 63, name: 'eight', surname: 'begin'},
+            {id: 4, name: 'you', surname: 'emotions'}
+        ];
+        data1.sort(function(a, b) { return a.id > b.id; }); // Sort by ID, lowest first.
+        data2.sort(function(a, b) { return a.id > b.id; }); // Sort by ID, lowest first.
+
+        // Js component instance
+        var mscL = new MultiSelectComponent('contacts', data1, 'id', function(item) { return item.name + ' ' + item.surname; });
+        var mscR = new MultiSelectComponent('users', data2, 'id', function(item) { return item.name + ' ' + item.surname; });
+        // Generated data added to template
+        var left = document.getElementById('left');
+        var right = document.getElementById('right');
+        left.innerHTML = mscL.createTemplate();
+        right.innerHTML = mscR.createTemplate();
+
+        // Initialization. May be done in more elegant way if the template is created ie. on server.
+        mscL.init();
+        mscR.init();
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/public/custom/multiselectcomponent/multiselectcomponent.js b/public/custom/multiselectcomponent/multiselectcomponent.js
new file mode 100644
index 00000000..65bdd36b
--- /dev/null
+++ b/public/custom/multiselectcomponent/multiselectcomponent.js
@@ -0,0 +1,121 @@
+
+/**
+ * Multi-select component
+ *
+ * @param identifier        Identifier parameter that makes each instance unique and is used in DOM datasets used by this component.
+ * @param data              Data (array of objects)
+ * @param field             Field parameter that will be send as list with form
+ * @param itemString        String that should be shown as selector in select and a item label in item list
+ */
+function MultiSelectComponent(identifier, data, field, itemString) {
+
+    // Private variables
+    var selectBox, addButton, itemHolder;
+
+    /**
+     * This is the method that generates template for multiselect component.
+     * This method is easily rewriteable into PHP.
+     * It is necessary to keep html datasets with prefix data-ms- intact for the javascript component to work.
+     * ECMAScript 5 version, does not need any compilers, nor jQuery or other framework.
+     * This method is not required to stay inside the MultiSelectComponent and may be rendered in any way;
+     *
+     * identifier is inherited from the instance creation.
+     * data is inherited from the instance creation.
+     * field is inherited from the instance creation.
+     * itemString is inherited from the instance creation.
+     *
+     */
+    function createTemplate () {
+        var html = '<select data-ms-select="'+identifier+'">';
+
+        for(var idx in data) {
+            if(data.hasOwnProperty(idx)) {
+                html += '<option value="'+data[idx][field]+'">'+itemString(data[idx])+'</value>' //createSelectOption(data[idx]);
+            }
+        }
+
+        return html += '</select><input type="button" data-ms-add="'+identifier+'" value="add"><div data-ms-list="'+identifier+'"></div>';
+    }
+
+    /**
+     * This method creates an item list item that works as visual representation of selected values.
+     */
+    function createItemListItem (value) {
+        return html = '<span>'+itemString(getDataItem(value))+
+            ' <span data-ms-remove="'+identifier+'" data-ms-value="'+value+'">x</span>'+
+            '<input style="display: none" type="checkbox" value="'+value+'" name="'+identifier+'[]" checked>'+
+            '</span>';
+    }
+
+    /**
+     * Returns a requested data item that matches <field> (class instance variable field) value of passed value.
+     */
+    function getDataItem (value) {
+        for(var idx in data) {
+            if(data.hasOwnProperty(idx)){
+                if(data[idx][field] == value){
+                    return data[idx];
+                }
+            }
+        }
+    }
+
+    /**
+     * By selecting an item, that item is removed from list of available items and is added to list of selected items.
+     * If no more items are available for adding, add button and selectbox are disabled and list gets an informative item.
+     */
+    function selectItem (value) {
+        selectBox.removeChild(selectBox.querySelector('option[value="' + value + '"]'));
+        itemHolder.innerHTML += createItemListItem(value);
+
+        if(selectBox.children.length === 0) {
+            selectBox.options.add(new Option('no more items to add', 0));
+            addButton.setAttribute('disabled', 'disabled');
+            selectBox.setAttribute('disabled', 'disabled');
+        }
+    }
+
+    /**
+     * By deselecting (removing) an item, that item is removed from selected list and added again into select box of available items;
+     * If add button was disabled (mostly because of no selectable items in list) it and the selectbox are now re-enabled and informative item is removed.
+     */
+    function deselectItem (element) {
+        var id = element.getAttribute('data-ms-value');
+        selectBox.options.add(new Option(itemString(getDataItem(id)), id));
+        itemHolder.removeChild(element.parentNode);
+
+        if(addButton.getAttribute('disabled')) {
+            selectBox.options.remove(0);
+            addButton.removeAttribute('disabled');
+            selectBox.removeAttribute('disabled');
+        }
+    }
+
+    /**
+     * Initializes javascript part of the component.
+     */
+    function init () {
+        // Cached elements only for JS to be a little more optimized.
+        selectBox = document.querySelector('[data-ms-select="'+identifier+'"]');
+        addButton = document.querySelector('[data-ms-add="'+identifier+'"]');
+        itemHolder = document.querySelector('[data-ms-list="'+identifier+'"]');
+
+        // Add button
+        addButton.addEventListener('click', function() {
+            selectItem(selectBox.value);
+        });
+
+        // Remove item button
+        itemHolder.addEventListener('click', function(e) {
+            if(e.target.getAttribute('data-ms-remove')) {
+                deselectItem(e.target);
+            }
+        })
+    }
+
+    // Publicly exposed static methods and variables.
+    return {
+        init: init,
+        createTemplate: createTemplate
+    };
+}
\ No newline at end of file