Since Tree Grid Databinding concept is of hierarchy relationship, we do not provide in-built support for foreignKey datasource.
To display the foreignKey value at initial rendering, we can use the queryCellInfo event of the Tree Grid and also by using the editType and columns.edit properties of Tree Grid Column, we can render Dropdownlist with external or foreign dataSource.
ej.treegrid.TreeGrid.Inject(ej.treegrid.Edit,ej.treegrid.Toolbar);
var treegrid = new ej.treegrid.TreeGrid({
dataSource: window.textdata,
childMapping: "Children",
treeColumnIndex: 1,
height: 269,
editSettings: {
allowEditing: true,
allowAdding: true,
allowDeleting: true,
mode: "Cell"
},
toolbar: ["Add", "Delete", "Update", "Cancel"],
treeColumnIndex: 1,
queryCellInfo: queryCellInfo,
columns: [
{ field: "EmpID", headerText: "EmpID", isPrimaryKey: true, textAlign: "Right", width: 80 },
{ field: "Name", headerText: "Employee Name", width: 70 },
{ field: "DOB", headerText: "DOB", textAlign: "Right", width: 70, editType: "datepickeredit",
format: { skeleton: "yMd", type: "date" } },
{ field: "EmployeeID", headerText: "EmployeeID", textAlign: "Right", editType: "dropdownedit",
edit: {
params: {
dataSource: new ej.data.DataManager(window.dropData),
fields: { text: "EmployeeName", value: "EmployeeID" },
query: new ej.data.Query()
}
},
width: 70 },
{ field: "Country", headerText: "Country", width: 90, textAlign: "Right" }
]
});
treegrid.appendTo("#TreeGrid");
function queryCellInfo(args) {
if (args.column.field === "EmployeeID") {
for (var i = 0; i < dropData.length; i++) {
let data = args.data;
if (data[args.column.field] === dropData[i]["EmployeeID"]) {
args.cell.innerText = dropData[i]["EmployeeName"]; // assign the foreignkey field value to the innertext
}
}
}
}#container {
visibility: hidden;
}
#loader {
color: #008cff;
font-family: 'Helvetica Neue','calibiri';
font-size: 14px;
height: 40px;
left: 45%;
position: absolute;
top: 45%;
width: 30%;
}<!DOCTYPE html><html lang="en"><head>
<title>EJ2 Grid</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="Typescript Grid Control">
<meta name="author" content="Syncfusion">
<link href="index.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-grids/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-treegrid/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-buttons/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-popups/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-navigations/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-dropdowns/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-lists/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-calendars/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/ej2-splitbuttons/styles/material.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script>
<script src="es5-datasource.js" type="text/javascript"></script>
</head>
<body>
<div id="container">
<div id="TreeGrid"></div>
</div>
<script>
var ele = document.getElementById('container');
if(ele) {
ele.style.visibility = "visible";
}
</script>
<script src="index.js" type="text/javascript"></script>
</body></html>