Question

I am using the $expand to get related data which works fine but I need to change the data that is sent back
to the server when the data is updated

Example if my Server Side Data Model contains two entities
Contact
ID: number
firstName: string
middleName: string
lastname: string
ContactType: ContactType n-1

ContactType
ID: nubmer
name: string
ContactCollection: ContactType 1-n

Here is my datasource code

function GetContactDS(){
        var MyModel = kendo.data.Model.define({
                                id: "ID",
                                fields: {
                                __KEY: { type: "string" },
                                __STAMP: { type: "number" },
                                ID: { editable: false, nullable: true },                                                               
                                firstName: { type: "string" },
                                middleName: { type: "string" },                                                        
                                lastName: { type: "string" }                               
                                },                             
                            });

            var crudServiceBaseUrl = "http://127.0.0.1:8081/cors/Contact";
            var  MyDataSource = new kendo.data.DataSource({
        transport: {
       read: function(options) {
               $.ajax( {
                url: crudServiceBaseUrl + '/?$expand=ContactType',
                dataType: "json",
                data: options.data,
                success: function(result) {
                    options.success(result);
                }
            });
        },

    update: function(options) {
            $.ajax( {
                url: crudServiceBaseUrl + "/?$method=update",
                type: "POST",
                dataType: "json",
                data: kendo.stringify(options.data.models),
                success: function(result) {
                    // notify the DataSource that the operation is complete

                    options.success(result);
                }
            });
        },
                                destroy: {
                                url: crudServiceBaseUrl + "/?$method=delete",
                                type: "GET"
                                },
                                create: {
                                url: crudServiceBaseUrl + "/?$method=update",
                                dataType: "json",
                                type: "POST"
                                },
                                          parameterMap: function(options, operation) {
                                    if (operation !== "read" && options.models) {
                                       return  JSON.stringify({"__ENTITIES": options.models});
                                    }
                                }
                                },
                                batch: true,
                                pageSize: 30,
                                schema: {
                                     model: MyModel,
                                    data: "__ENTITIES"                         
                                    }

            });

      return MyDataSource;
}

The read request returns this data

{"__entityModel":"Contact","__COUNT":1,"__SENT":1,"__FIRST":0,"__ENTITIES":[{"__KEY":"7","__STAMP":9,"ID":7,"firstName":"jay","middleName":"a","lastName":"blue","ContactType":{"__KEY":"2","__STAMP":4,"ID":2,"name":"Home","contactCollection":{"__deferred":{"uri":"/rest/ContactType(2)/contactCollection?$expand=contactCollection"}}}}]}

Here is the code calling read and binding to grid

var ContactDS = GetContactDS();

    $("#grid").kendoGrid({
        selectable: "row",
        filterable: true,
        pageable: true,
        sortable: true,
        change: function(){

                 datamodel = this.dataItem(this.select());
                 ID = datamodel.ID

        },
        dataSource: ContactDS,
        columns: [
            { field: "ID" },
            { field: "firstName" },
            { field: "middleName" },
            { field: "lastName" },
            {field: "ContactType.name"}

        ]
    });

Which works fine I am getting the expanded info for ContactType in my datasource and it binds to a grid fine.
Now I want to update the after it the selected data row is read into a form, reading the data into the form works fine.

The problem is sending the update back to the server which expects a slightly different format for the related entity ContactType
It only needs the changed value of “__Key” to update
Here is my update function:

$("#update").click(function () {
                  datamodel.set("firstName", $("#firstName").val());
                  datamodel.set("lastName", $("#lastName").val());
                  datamodel.set("middleName", $("#middleName").val());
               //   datamodel.set("ContactType.__KEY",3);



                  ContactDS.sync();

Here is the data that the server expects

{ "__ENTITIES": [{"__KEY":"7","__STAMP":14,"firstName":"jay","middleName":"a","lastName":"red","ContactType":{"__KEY":"2"}}]}

Here is what kendo.datasource is sending

[{"__KEY":"7","__STAMP":12,"ID":7,"firstName":"jay","middleName":"a","lastName":"blue","ContactType":{"__KEY":"3","__STAMP":2,"ID":3,"name":"Work","contactCollection":{"__deferred":{"uri":"/rest/ContactType(3)/contactCollection?$expand=contactCollection"}}}}]

So how do I either reformat the data or define my model or datasource options to make sure that the extra ContactType fields are removed just leaving the updated “_KEY:” as well as wrapping the whole request in { “_ENTITIES”:}

Thanks for any help!

Dan

Answer 1

I think I found the answer from this post

It explains a little more on using parameterMap. If you look at the kendoui docs on parameterMap it seems to indicate that this is only for managing parameters like
pageIndex,size,orderBy ect. But from the above post it shows you how to delete a related entity or you can just delete or modify the fields of an entity or related entity

Example I can delete just the ContactTypeID of the related entity ContactType

parameterMap: function(options, operation) {

                            if (operation == "create") {

                            return  JSON.stringify({"__ENTITIES": options.models});
                            }
                            else if (operation == "update") {
                                debugger;
                            delete options.models[0].ContactType.ID;
                            return  JSON.stringify({"__ENTITIES": options.models});
                             }
                        }

Still have some work to do but I think this will get me there

Thanks Pechka for your help