Data Adaptors in ASP.NET Core Datamanager
9 Dec 202124 minutes to read
DataManger uses adaptors to process data. There are three types of adaptors in DataManger. They are
-
JSON Adaptor
-
URL Adaptor
-
OData Adaptor
Here, you can learn when and how each adaptor is used.
JSON Adaptor
JSONAdaptor is used to process JSON data. It contains methods to process the given JSON data based on the queries.
JSONAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| processQuery(ds, query) |
|
Used to prepare query string for the request data | ||||||||||||
| processResponse(data, ds, query, xhr) |
|
Used to precess the response which is return from the Data Source | ||||||||||||
| insert(dm, data) |
|
Inserts a data item in the data table. | ||||||||||||
| remove(dm, keyField, value, tableName) |
|
It is used to remove the data from the dataSource | ||||||||||||
| update(dm, keyField, value, tableName) |
|
Updates existing record and saves the changes to the table.. |
The following code example illustrates on how to use JSONAdaptor.
public static List<OrderDetails> order = new List<OrderDetails>();
public IActionResult DataAdaptors()
{
BindDataSource();
ViewBag.datasource = order;
return View();
}
public void BindDataSource()
{
int code = 10000;
for (int i = 1; i < 10; i++)
{
order.Add(new OrderDetails(code + 1, "ALFKI", i + 0, 2.3 * i, "Berlin"));
order.Add(new OrderDetails(code + 2, "ANATR", i + 2, 3.3 * i, "Madrid"));
order.Add(new OrderDetails(code + 3, "ANTON", i + 1, 4.3 * i, "Cholchester"));
order.Add(new OrderDetails(code + 4, "BLONP", i + 3, 5.3 * i, "Marseille"));
order.Add(new OrderDetails(code + 5, "BOLID", i + 4, 6.3 * i, "Tsawassen"));
code += 5;
}
}
public class OrderDetails
{
public OrderDetails()
{
}
public OrderDetails(int OrderID, string CustomerId, int EmployeeId, double Freight, string ShipCity)
{
this.OrderID = OrderID;
this.CustomerID = CustomerId;
this.EmployeeID = EmployeeId;
this.Freight = Freight;
this.ShipCity = ShipCity;
}
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public int? EmployeeID { get; set; }
public double? Freight { get; set; }
public string ShipCity { get; set; }
}/*ej-Tag Helper code to render DataManager*/
<ej-grid id="FlatGrid">
<e-datamanager json="(IEnumerable<object>)ViewBag.datasource" adaptor="JsonAdaptor"></e-datamanager>
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="70"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").Json((IEnumerable<object>)ViewBag.datasource).Adaptor(AdaptorType.JsonAdaptor).Render();}
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).page(2, 8)")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}The result of above code example is illustrated as follows.
URL Adaptor
URL Adaptor of DataManager can be used when you are required to use remote service to retrieve data. It interacts with server-side for all DataManager Queries and CRUD operations.
UrlAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| processQuery(dm, query, hierarchyFilters) |
|
Used to prepare query string for the request data | ||||||||||||||||||
| processResponse(data, ds, query, xhr, request, changes) |
|
Used to precess the response which is return from the Data Source | ||||||||||||||||||
| insert(dm, data, tableName, query) |
|
Inserts a data item in the data table. | ||||||||||||||||||
| remove(dm, keyField, value, tableName, query) |
|
It is used to remove the data from the dataSource | ||||||||||||||||||
| update(dm, keyField, value, tableName, query) |
|
Updates existing record and saves the changes to the table.. |
Now, in the following code example the data is retrieved from MVC Controller.
public static List<OrderDetails> order = new List<OrderDetails>();
public IActionResult DataAdaptors()
{
return View();
}
public JsonResult DataSource()
{
int code = 10000;
for (int i = 1; i < 10; i++)
{
order.Add(new OrderDetails(code + 1, "ALFKI", i + 0, 2.3 * i, "Berlin"));
order.Add(new OrderDetails(code + 2, "ANATR", i + 2, 3.3 * i, "Madrid"));
order.Add(new OrderDetails(code + 3, "ANTON", i + 1, 4.3 * i, "Cholchester"));
order.Add(new OrderDetails(code + 4, "BLONP", i + 3, 5.3 * i, "Marseille"));
order.Add(new OrderDetails(code + 5, "BOLID", i + 4, 6.3 * i, "Tsawassen"));
code += 5;
}
var list = order.ToList();
return Json(new { result = list, count = list.Count });
}
public class OrderDetails
{
public OrderDetails()
{
}
public OrderDetails(int OrderID, string CustomerId, int EmployeeId, double Freight, string ShipCity)
{
this.OrderID = OrderID;
this.CustomerID = CustomerId;
this.EmployeeID = EmployeeId;
this.Freight = Freight;
this.ShipCity = ShipCity;
}
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public int? EmployeeID { get; set; }
public double? Freight { get; set; }
public string ShipCity { get; set; }
}/*ej-Tag Helper code to render DataManager*/
<ej-grid id="FlatGrid" query="new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(5)">
<e-datamanager url="DataSource" adaptor="UrlAdaptor" ></e-datamanager>
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="75"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>/*Razor code to render DataManager*/
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(5)")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}NOTE
MVC now serializes JSON with camel case names by default in ASP.NET Core.
In previous milestones, MVC’s JSON serialization used Json.NET’s default naming convention. This maintained C# property names in the JSON.
In 1.0.0, MVC uses camel case names by default. This matches most JSON naming conventions.
To restore previous naming strategy
If you have case-sensitive clients that cannot be easily updated, change your Startup fromservices.AddMvc();
to
services.AddMvc().AddJsonOptions(options => options.SerializerSettings.ContractResolver = new DefaultContractResolver());
The result of the above code example is illustrated as follows.
OData Adaptor
OData Adaptor that is extended from UrlAdaptor, is used for consuming data through OData Service. You can use the following code example to use OData adaptor.
ODataAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| processResponse(data, ds, query, xhr, request, changes) |
|
Used to precess the response which is return from the Data Source | ||||||||||||||||||
| insert(dm, data, tableName) |
|
Inserts a data item in the data table. | ||||||||||||||||||
| remove(dm, keyField, value, tableName) |
|
It is used to remove the data from the dataSource | ||||||||||||||||||
| update(dm, keyField, value, tableName) |
|
Updates existing record and saves the changes to the table.. |
/*ej-Tag Helper code to render DataManager*/
<ej-grid id="FlatGrid" query="new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(5)">
<e-datamanager url="http://mvc.syncfusion.com/Services/Northwnd.svc/Orders/" adaptor="ODataAdaptor"></e-datamanager>
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="75"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").URL("http://mvc.syncfusion.com/Services/Northwnd.svc/Orders/").Adaptor(AdaptorType.ODataAdaptor).Render();}
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData").ClientSideEvents(e => e.Create("onCreate"))
.Query("new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(5)")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}The result of the above code example is illustrated as follows.
WebAPI Adaptor
WebApi Adaptor, extended from ODataAdaptor, of DataManager is used for retrieving data from WebApi service.
WebApiAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| processResponse(data, ds, query, xhr, request, changes) |
|
Used to precess the response which is return from the Data Source | ||||||||||||||||||
| insert(dm, data, tableName) |
|
Inserts a data item in the data table. | ||||||||||||||||||
| remove(dm, keyField, value, tableName) |
|
It is used to remove the data from the dataSource | ||||||||||||||||||
| update(dm, keyField, value, tableName) |
|
Updates existing record and saves the changes to the table.. |
Refer to the following code example.
public class OrdersController : Controller
{
public static List<OrderDetails> order = new List<OrderDetails>();
// GET: api/values
[HttpGet]
public JsonResult Get()
{
int code = 10000;
for (int i = 1; i < 2; i++)
{
order.Add(new OrderDetails(code + 1, "ALFKI", i + 0, 2.3 * i, "Berlin"));
order.Add(new OrderDetails(code + 2, "ANATR", i + 2, 3.3 * i, "Madrid"));
order.Add(new OrderDetails(code + 3, "ANTON", i + 1, 4.3 * i, "Cholchester"));
order.Add(new OrderDetails(code + 4, "BLONP", i + 3, 5.3 * i, "Marseille"));
order.Add(new OrderDetails(code + 5, "BOLID", i + 4, 6.3 * i, "Tsawassen"));
code += 5;
}
var list = order.ToList();
return Json(new { result = list, count = list.Count });
}
public class OrderDetails
{
public OrderDetails()
{
}
public OrderDetails(int OrderID, string CustomerId, int EmployeeId, double Freight, string ShipCity)
{
this.OrderID = OrderID;
this.CustomerID = CustomerId;
this.EmployeeID = EmployeeId;
this.Freight = Freight;
this.ShipCity = ShipCity;
}
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public int? EmployeeID { get; set; }
public double? Freight { get; set; }
public string ShipCity { get; set; }
}
}/*ej-Tag Helper code to render DataManager*/
<ej-grid id="FlatGrid" query="new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID'])">
<e-datamanager url="/api/Orders" adaptor="WebApiAdaptor"></e-datamanager>
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="75"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").URL("/api/Orders").Adaptor(AdaptorType.WebApiAdaptor).Render();}
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID'])")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}Result of the above code example is illustrated as follows.
RemoteSave Adaptor
RemoteSaveAdaptor, extended from JsonAdaptor of DataManager, is used for binding local data and performs all DataManager queries in client-side. It interacts with server-side only for CRUD operations to pass the modified records.
JSONAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| insert(dm, data, tableName, query) |
|
Inserts a data item in the data table. | |||||||||||||||
| remove(dm, keyField, value, tableName, query) |
|
It is used to remove the data from the dataSource | |||||||||||||||
| update(dm, keyField, value, tableName, query) |
|
Updates existing record and saves the changes to the table.. |
Refer to the following code example.
<div>
<div class="row">
<div class="col-md-3">
OrderID
</div>
<div class="col-md-3">
<input id="OrderID" class="e-ejinputtext" type="text" value="" />
</div>
</div>
<div class="row">
<div class="col-md-3">
Customer ID
</div>
<div class="col-md-3">
<input id="CustomerID" class="e-ejinputtext" type="text" value="" />
</div>
</div>
<div class="row">
<div class="col-md-3">
Employee ID
</div>
<div class="col-md-3">
<input id="EmployeeID" class="e-ejinputtext" type="text" value="" />
</div>
</div>
<div class="row">
<div class="col-md-3">
<input type="button" value="Change" />
<input type="button" value="Add" />
<input type="button" value="Remove" />
</div>
</div>
</div>/*ej-Tag Helper code to render DataManager*/
<e-datamanager id="myData" json="(IEnumerable<object>)ViewBag.datasource" adaptor="remoteSaveAdaptor" insert-url="Insert" update-url="Update" remove-url="Remove"></e-datamanager>
<ej-grid id="FlatGrid" allow-paging="true">
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="70"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>
<script>
setTimeout(function () {
var query = ej.Query();
var promise = window.myData.executeLocal(query);
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(promise);
});
$("input:button").ejButton({
click: function (args) {
if (document.activeElement.value == "Change") {
var data = window.myData.executeLocal(new ej.Query().where("OrderID", ej.FilterOperators.equal, $("#OrderID").val(), 10));
if (data.length) {
data[0].OrderID = $("#OrderID").val();
data[0].CustomerID = $("#CustomerID").val();
data[0].EmployeeID = $("#EmployeeID").val();
window.myData.update("OrderID", data[0]).done(function (e) {
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.myData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
}
if (document.activeElement.value == "Add") {
var data = { OrderID: $("#OrderID").val(), CustomerID: $("#CustomerID").val(), EmployeeID: $("#EmployeeID").val() };
window.myData.insert(data).done(function (e) {
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.myData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
if (document.activeElement.value == "Remove") {
var data = $("#OrderID").val();
if (data.length) {
window.myData.remove("OrderID", data).done(function (e) {
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.myData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
}
}
});
</script>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").Json((IEnumerable<object>)ViewBag.datasource).Adaptor("remoteSaveAdaptor").InsertURL("Insert").UpdateURL("Update").RemoveURL("Remove").Render();}
@{ Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query()")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}
<script>
$("input:button").ejButton({
click: function (args) {
if (document.activeElement.value == "Change") {
var data = window.FlatData.executeLocal(new ej.Query().where("OrderID", ej.FilterOperators.equal, $("#OrderID").val(), 10));
if (data.length) {
data[0].OrderID = $("#OrderID").val();
data[0].CustomerID = $("#CustomerID").val();
data[0].EmployeeID = $("#EmployeeID").val();
window.FlatData.update("OrderID", data[0]).done(function (e) {
var gridObj = $("#myGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.FlatData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
}
if (document.activeElement.value == "Add") {
var data = { OrderID: $("#OrderID").val(), CustomerID: $("#CustomerID").val(), EmployeeID: $("#EmployeeID").val() };
window.FlatData.insert(data).done(function (e) {
var gridObj = $("#myGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.FlatData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
if (document.activeElement.value == "Remove") {
var data = $("#OrderID").val();
if (data.length) {
window.FlatData.remove("OrderID", data).done(function (e) {
var gridObj = $("#myGrid").ejGrid("instance");
gridObj.dataSource(e.record.result);
window.FlatData.dataSource.json = e.record.result;
window.changes = null;
$(".e-ejinputtext").val("");
})
}
}
}
});
</script>public class HomeController : Controller
{
public static IList<EditableOrder> Data()
{
IList<EditableOrder> records = (IList<EditableOrder>)System.Web.HttpContext.Current.Session["Orders"];
if (records == null)
{
List<EditableOrder> temp = new List<EditableOrder>();
for (int i = 1; i <= 5; i++)
{
var order = new EditableOrder() { OrderID = 10247 + i, CustomerID = "Customer" + i, EmployeeID = i };
temp.Add(order);
}
System.Web.HttpContext.Current.Session["Orders"] = records = temp;
}
return records;
}
public JsonResult Update(EditableOrder value)
{
var record = Data().Where(o => o.OrderID == value.OrderID).FirstOrDefault();
if (record != null)
{
record.OrderID = value.OrderID;
record.CustomerID = value.CustomerID;
record.EmployeeID = value.EmployeeID;
}
return Json(Data(), JsonRequestBehavior.AllowGet);
}
public JsonResult Insert(EditableOrder value)
{
Data().Insert(0, value);
return Json(Data(), JsonRequestBehavior.AllowGet);
}
public JsonResult Remove(int key)
{
var record = Data().Where(o => o.OrderID == key).FirstOrDefault();
Data().Remove(record);
return Json(Data(), JsonRequestBehavior.AllowGet);
}
}Custom Adaptor
Custom adaptor is a key technique to customize adaptors in DataManager. It is useful to write own adaptor. Normally ej.Adaptor is base class for all adaptors. Therefore you first inherit ej.Adaptor to develop customized one and then you override functionality in custom adaptor with base class.
The following code example illustrates you on how to create custom adaptor.
/*ej-Tag Helper code to render DataManager*/
<e-datamanager id="myData" json="(IEnumerable<object>)ViewBag.datasource"></e-datamanager>
<ej-grid id="FlatGrid" allow-paging="true">
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="70"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>
<script>
setTimeout(function () {
var customAdaptor = new ej.Adaptor().extend({
insert: function (dm, data) {
return dm.dataSource.json.push(data);
},
processQuery: ej.JsonAdaptor.prototype.processQuery // reused process query from json adaptor
});
window.myData.adaptor = new customAdaptor();
window.myData.insert({ OrderID: 100034, CustomerID: "ZWDRS", EmployeeID: 9 });
var query = ej.Query();
var promise = window.myData.executeLocal(query);
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(promise);
});
</script>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").Json((IEnumerable<object>)ViewBag.datasource).Render();}
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query()")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}
<script>
setTimeout(function () {
var customAdaptor = new ej.Adaptor().extend({
insert: function (dm, data) {
return dm.dataSource.json.push(data);
},
processQuery: ej.JsonAdaptor.prototype.processQuery // reused process query from json adaptor
});
window.FlatData.adaptor = new customAdaptor();
window.FlatData.insert({ OrderID: 100034, CustomerID: "ZWDRS", EmployeeID: 9 });
var query1 = ej.Query();
var promise1 = window.FlatData.executeLocal(query1);
var gridObj = $("#myGrid").ejGrid("instance");
gridObj.dataSource(promise1);
});
</script>Result of above code example is as follows.
Using Custom Adaptor, you can override the existing method of Extended Adaptor,
| Properties |
Description |
|---|---|
| beforeSend | Custom headers can be set using pre-request callback beforeSend, by using the setRequestHeader method can be used to modify the XMLHTTPRequest |
| processQuery | Used to prepare query string for the request data |
| processResponse | Used to precess the response which is return from the Data Source |
| insert | The insert method of the data manager is used to add a new record to the table |
| remove | The remove action submits the data items that should be deleted |
| update | The update method is used to update the modified changes made to a record in the data source of the DataManager. |
Cache Adaptor
Cache Adaptor is used to cache the data of the visited pages. It prevents new requests for the previously visited pages. It can be enabled by using the enableCaching property. You can configure cache page size and duration of caching by using cachingPageSize and timeTillExpiration properties of the ej.DataManager.
CacheAdaptor has the following unique in-built methods,
| Properties |
Parameters |
Description |
||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| processQuery(dm, query, hierarchyFilters) |
|
Used to prepare query string for the request data | ||||||||||||||||||
| processResponse(data, ds, query, xhr, request, changes) |
|
Used to precess the response which is return from the Data Source | ||||||||||||||||||
| insert(dm, data, tableName) |
|
Inserts a data item in the data table. | ||||||||||||||||||
| remove(dm, keyField, value, tableName) |
|
It is used to remove the data from the dataSource | ||||||||||||||||||
| update(dm, keyField, value, tableName) |
|
Updates existing record and saves the changes to the table.. |
namespace WebApplication1.Controllers
{
[Route("api/[controller]")]
public class OrdersController : Controller
{
public static List<OrderDetails> order = new List<OrderDetails>();
// GET: api/values
[HttpGet]
public JsonResult Get()
{
int code = 10000;
for (int i = 1; i < 2; i++)
{
order.Add(new OrderDetails(code + 1, "ALFKI", i + 0, 2.3 * i, "Berlin"));
order.Add(new OrderDetails(code + 2, "ANATR", i + 2, 3.3 * i, "Madrid"));
order.Add(new OrderDetails(code + 3, "ANTON", i + 1, 4.3 * i, "Cholchester"));
order.Add(new OrderDetails(code + 4, "BLONP", i + 3, 5.3 * i, "Marseille"));
order.Add(new OrderDetails(code + 5, "BOLID", i + 4, 6.3 * i, "Tsawassen"));
code += 5;
}
var list = order.ToList();
return Json(new { result = list, count = list.Count });
}
public class OrderDetails
{
public OrderDetails()
{
}
public OrderDetails(int OrderID, string CustomerId, int EmployeeId, double Freight, string ShipCity)
{
this.OrderID = OrderID;
this.CustomerID = CustomerId;
this.EmployeeID = EmployeeId;
this.Freight = Freight;
this.ShipCity = ShipCity;
}
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public int? EmployeeID { get; set; }
public double? Freight { get; set; }
public string ShipCity { get; set; }
}
}
}/*ej-Tag Helper code to render DataManager*/
<e-datamanager id="myData" url="/api/Orders" adaptor="WebApiAdaptor" caching-page-size="4" enable-caching="true" time-till-expiration="12000" cross-domain="true"></e-datamanager>
<ej-grid id="FlatGrid" >
<e-columns>
<e-column field="OrderID" header-text="Order ID" text-align="Right" width="70"></e-column>
<e-column field="CustomerID" header-text="Customer ID" width="80"></e-column>
<e-column field="EmployeeID" header-text="Employee ID" text-align="Left" width="75"></e-column>
</e-columns>
</ej-grid>
<script>
setTimeout(function () {
var query = ej.Query().select("OrderID", "CustomerID", "EmployeeID").take(5);
var execute = window.myData.executeQuery(query) // executing query
.done(function (e) {
var gridObj = $("#FlatGrid").ejGrid("instance");
gridObj.dataSource(e.result.result);
});
});
</script>/*Razor code to render DataManager*/
@{Html.EJ().DataManager("FlatData").URL("/api/Orders").Adaptor(AdaptorType.WebApiAdaptor).EnableCaching().CachingPageSize(4).TimeTillExpiration(12000).Render();}
@{Html.EJ().Grid<object>("myGrid")
.DataManagerID("FlatData")
.Query("new ej.Query().select(['OrderID', 'CustomerID', 'EmployeeID']).take(5)")
.Columns(col =>
{
col.Field("OrderID").HeaderText("Order ID").IsPrimaryKey(true).TextAlign(TextAlign.Right).Width(75).Add();
col.Field("CustomerID").HeaderText("Customer ID").Width(80).Add();
col.Field("EmployeeID").HeaderText("Employee ID").TextAlign(TextAlign.Right).Width(75).Add();
}).Render();
}
Cache Adaptor has the following unique properties,
| Properties |
Description |
|---|---|
| TimeTillExpiration | Specifies the duration of cached pages in milliseconds |
| CachingPageSize | A number of pages to be cached |