Populate Data

TreeView can be populated with local or remote data source by using a property dataSource, which is the member of fields property.

In TreeView, you should use “fields” property to go with data source. It specifies the mapping fields for the data source to receive the data, query to process the data and field mappers to map the data members.

Fields

The following table contains the list of members with description for fields property.

Properties Description

dataSource



The data source contains the list of data for generating the TreeView list.

query



It specifies the query to retrieve the data from the online server.

tableName



It specifies the name of the table from which data to be processed from given data source.

id



It specifies the ID of the node.

parentId



It specifies the parent id of the node

text



It specifies the text content of the node.

hasChild



It specifies the node has child (which is the nested or inner level of nodes). Also it’s used in load on demand of tree data.

expanded



It specifies the tree node to be in expanded state

selected



It specifies the select node at initialize. N> only one node get selected by default. If you enable multiple selection in TreeView then you can able to select one or more nodes at initialize.

isChecked



It specifies the node to be in checked state, if tree node represented with checkboxes.

imageUrl



It defines the image location.

imageAttribute



It defines the image attributes such as height, width, styles, etc.

spriteCssClass



It defines the sprite CSS for the image tag.

htmlAttribute



It defines the HTML attributes such as class and styles for a node ("li" tag).

linkAttribute



It defines the HTML attributes such as class and styles for a link tag, which is child of node.

Mapping all fields members with corresponding key from the array of JSON data.

  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
    
    
    module TreeViewComponent {
    
            var localData = [
    
           { id: 1, text: "Item 1", expanded: true, nodeProperty: { class: "textBlue", value: "Item 1" } },
    
           { id: 2, text: "Item 2", linkProperty: { class: "textUnderline", href: "http://www.syncfusion.com", target: "_blank" } },
    
           { id: 3, text: "Item 3", selected: true, spriteImage: "mail-icon sprite-calendar" },
    
           { id: 4, text: "Item 4", checked: true, imageProperty: { width: 20, height: 20 }, imageUrl: "http://cdn.syncfusion.com/13.3.0.7/js/web/flat-azure/images/ajax-loader.gif" },
    
           { id: 5, parent: 1, text: "Item 1.1" },
    
           { id: 6, parent: 1, text: "Item 1.2" },
    
           { id: 7, parent: 1, text: "Item 1.3" },
    
           { id: 8, parent: 3, text: "Item 3.1" },
    
           { id: 9, parent: 3, text: "Item 3.2" },
    
           { id: 10, parent: 5, text: "Item 1.1.1" }
    
            ];
    
        $(function () {
    
            var tree = new ej.TreeView($("#treeView"), {
    
                    showCheckbox: true,
    
                    fields: {
    
                        id: "id",
    
                        text: "text",
    
                        parentId: "parent",
    
                        dataSource: localData,
    
                        isChecked: "checked",
    
                        selected: "selected",
    
                        spriteCssClass: "spriteImage",
    
                        imageUrl: "imageUrl",
    
                        htmlAttribute: "nodeProperty",
    
                        linkAttribute: "linkProperty",
    
                        imageAttribute: "imageProperty"
    
                    }
    
                });
    
            });
    }

    NOTE

    If you want to display nodes in Root level, exclude parentId attribute or specify “0” in corresponding value.

    To find the complete details about fields, refer the sample here.

    Local Data

    TreeView can be rendered from a self-referential data by providing the two required fields id and parentId.

  • js
  • var localData = [
    
            { id: 1, text: "Item 1" },
    
            { id: 2, text: "Item 2" },
    
            { id: 3, text: "Item 3" },
    
            { id: 4, text: "Item 4" },
    
            { id: 5, parent: 1, text: "Item 1.1" }
    
            ];

    Above flat array of JSON data can be directly assigned to dataSource property and mapping data fields with respect to the mapper field in order to create TreeView.

  • html
  • <!--create the TreeView wrapper-->
    
        <div id="treeView">
    
        </div>
  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
     
    
    module TreeViewComponent {
    
            var localData = [
    
            { id: 1, text: "Item 1" },
    
            { id: 2, text: "Item 2" },
    
            { id: 3, text: "Item 3" },
    
            { id: 4, text: "Item 4" },
    
            { id: 5, parent: 1, text: "Item 1.1" },
    
            { id: 6, parent: 1, text: "Item 1.2" },
    
            { id: 7, parent: 1, text: "Item 1.3" },
    
            { id: 8, parent: 3, text: "Item 3.1" },
    
            { id: 9, parent: 3, text: "Item 3.2" },
    
            { id: 10, parent: 5, text: "Item 1.1.1" }
    
            ];
    
            $(function () {
    
                // initialize and bind the TreeView with local data
    
                var tree = new ej.TreeView($("#treeView"), {
    
                    fields: { dataSource: localData, id: "id", parentId: "parent", text: "text" }
    
                });
    
            });
    }

    Nested Object Support

    The nested object support is provided for the TreeView component. Please find the following JSON.

  • js
  • var localData = [
              { id: 1, name: { nodeName: "Discover Music"}, hasChild: true, expanded: true },
              { id: 2, parent: 1, name: {nodeName:"Hot Singles" }},
              { id: 3, parent: 1, name: {nodeName:"Rising Artists" }},
              { id: 4, parent: 1, name:{nodeName: "Live Music" }}
            ];

    Above flat array of JSON data can be directly assigned to dataSource property and mapping data fields with respect to the mapper field in order to create TreeView.

  • html
  • <!--create the TreeView wrapper-->
    
        <div id="treeView">
    
        </div>
  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
     
    
    module TreeViewComponent {
    
             var localData = [
              { id: 1, name: { nodeName: "Discover Music"}, hasChild: true, expanded: true },
              { id: 2, parent: 1, name: {nodeName:"Hot Singles" }},
              { id: 3, parent: 1, name: {nodeName:"Rising Artists" }},
              { id: 4, parent: 1, name:{nodeName: "Live Music" }}
            ];
    
            $(function () {
    
                // initialize and bind the TreeView with local data contains nested object
    
                var tree = new ej.TreeView($("#treeView"), {
    
                    fields: { dataSource: localData, id: "id", parentId: "parent", text: "name.nodeName" }
    
                });
    
            });
    }

    Remote Data

    When using remote data binding, the adaptor of ej.DataManager plays vital role in processing queries to make them suitable to sends along with data request and also process the response data from the server.

    OData

    OData is a standardized protocol for creating and consuming data. You can bind oData service data to TreeView in two ways using DataManager.

    • Passing OData service link to DataManager

    You can provide the OData service URL directly to the ej.DataManager class and then we can assign it to TreeView dataSource.

  • html
  • <!--create the TreeView wrapper-->
    
        <div id="treeView">
    
        </div>
  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
     
    
    module TreeViewComponent {
            var parentData = ej.DataManager("http://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Categories"),
    
            childData = ej.DataManager("http://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Products");
    
            $(function () {
    
                // initialize and bind the TreeView with remote data
    
                var tree = new ej.TreeView($("#treeView"), {
    
                    fields: {
    
                        dataSource: parentData,
    
                        id: "CategoryID", text: "CategoryName",
    
                        child: {
    
                            dataSource: childData,
    
                            id: "ProductID", parentId: "CategoryID", text: "ProductName"
    
                        }
    
                    }
    
                });
    
            });
    }

    Load on Demand

    Load on demand is a technique (Lazy load) that is used to reduce the bandwidth size of consuming huge data. You can load data on demand in TreeView by using loadOnDemand property when you’re going to use huge data.

    For local data source, TreeView loads the first level nodes initially. While expand a parent node then TreeView loads it’s their child nodes from the data source based on the parentId member. It reduces the time to render TreeView with huge data.

    Refer below code example to load data on demand from local data source.

  • html
  • <!--create the TreeView wrapper-->
    
    <div id="treeview"></div>
  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
     
    module TreeViewComponent {
    var localData = [
        { id: 1, name: "Local Disk(C:)", hasChild: true },
        { id: 2, name: "Local Disk(D:)", hasChild: true },
        { id: 3, name: "Local Disk(E:)", hasChild: true },
        { id: 4, parentId: 1, name: "Folder 1", hasChild: true },
        { id: 5, parentId: 1, name: "Folder 2" },
        { id: 6, parentId: 1, name: "Folder 3" },
        { id: 7, parentId: 2, name: "Folder 4" },
        { id: 8, parentId: 2, name: "Folder 5", hasChild: true },
        { id: 9, parentId: 2, name: "Folder 6" },
        { id: 10, parentId: 3, name: "Folder 7" },
        { id: 11, parentId: 3, name: "Folder 8" },
        { id: 12, parentId: 3, name: "Folder 9", hasChild: true },
        { id: 13, parentId: 4, name: "File 1" },
        { id: 14, parentId: 4, name: "File 2" },
        { id: 15, parentId: 4, name: "File 3" },
        { id: 16, parentId: 8, name: "File 4" },
        { id: 17, parentId: 8, name: "File 5" },
        { id: 18, parentId: 8, name: "File 6" },
        { id: 19, parentId: 12, name: "File 7" },
        { id: 20, parentId: 12, name: "File 8" },
        { id: 21, parentId: 12, name: "File 9" }
    ];
    $(function () {
         var tree = new ej.TreeView($("#treeView"), {
            loadOnDemand: true,
            fields: { dataSource: localData, id: "id", parentId: "parentId", text: "name", hasChild: "hasChild" },
        });
     });
    }

    The following screenshot displays the load on demand for local data source in TreeView control.

    While expanding the parent node

    After expanding the parent node

    For more details about load on demand for local data source, refer the sample here.

    For remote data source, TreeView loads the first level nodes initially. While expand the node from TreeView, the data manager passes the query to the controller. Based on this query, you can filter the data from table and return to TreeView.

    Refer below code example to load data on demand from remote data source.

  • html
  • <!--create the TreeView wrapper-->
    
    <div id="treeview"></div>
  • js
  • /// <reference path="tsfiles/jquery.d.ts" />
    /// <reference path="tsfiles/ej.web.all.d.ts" />
    
    module TreeViewComponent {
        $(function () {
        // DataManager creation
        var dataManger = ej.DataManager({
            url: "http://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/"
        });
        // Query creation
        var query = ej.Query().from("Categories").select("CategoryID,CategoryName").take(3);
        var tree = new ej.TreeView($("#treeView"), {
            loadOnDemand: true,
            fields: {
                dataSource: dataManger, query: query, id: "CategoryID", text: "CategoryName", hasChild: "CategoryName",
                child: { dataSource: dataManger, tableName: "Products", parentId: "CategoryID", text: "ProductName" }
            }
        });
     });
    }