Question

I have a function that uses case to return an object

    function GetModel(mymodel){

    var mydatamodel = null; 
    switch(mymodel)
    {
    case 'Contact':
    mydatamodel = kendo.data.Model.define({
                                    id: "__KEY",
                                    fields: {
                                    __KEY: { type: "string" },
                                    __STAMP: { type: "number" },
                                    ID: { editable: false, nullable: true },                                                                
                                    firstName: { type: "string" },
                                    middleName: { type: "string" },                                                         
                                    lastName: { type: "string" }
                                    }                               
                                });
                                break;

    case 'Address':
    mydatamodel = kendo.data.Model.define({
                                    id: "__KEY",
                                    fields: {
                                    __KEY: { type: "string" },
                                    __STAMP: { type: "number" },
                                    ID: { editable: false, nullable: true },                                                                
                                    street: { type: "string" }
                                    }                               
                                });
                                break;
    case 'ContactType':     
    mydatamodel = kendo.data.Model.define({
                                    id: "__KEY",
                                    fields: {
                                    __KEY: { type: "string" },
                                    __STAMP: { type: "number" },
                                    ID: { editable: false, nullable: true },                                                                
                                    name: { type: "string" }                                
                                    }                               
                                });
                                break;
    };

    return mydatamodel  
    };

//Try to create new instance
var mymodel = new GetModel("Contact")

Now this function does return an object but the object is not the same as
using the below code to create a new object which is what I need

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

//Create new object;
var mymodel = new mydatamodel();

This works as expected and creates a new instance of the kendoui.datamodel where
the function returns the kendoui.data.modal…. as a function and not a new instance of the object

I would like to be able to call a switch function because I want this code in a different .js file then the main .html page for code seperation. So how would
I go about getting the above function GetModel to act in the same way as the
var = kendoui.data.model… is working

Thanks,

Dan

Answer 1

Don’t use the new operator on your function.

Just make the function return an instance like this:

function GetModel(mymodel){

var mydatamodel = null; 
switch(mymodel)
{
case 'Contact':
mydatamodel = kendo.data.Model.define({
                                id: "__KEY",
                                fields: {
                                __KEY: { type: "string" },
                                __STAMP: { type: "number" },
                                ID: { editable: false, nullable: true },                                                                
                                firstName: { type: "string" },
                                middleName: { type: "string" },                                                         
                                lastName: { type: "string" }
                                }                               
                            });
                            break;

case 'Address':
mydatamodel = kendo.data.Model.define({
                                id: "__KEY",
                                fields: {
                                __KEY: { type: "string" },
                                __STAMP: { type: "number" },
                                ID: { editable: false, nullable: true },                                                                
                                street: { type: "string" }
                                }                               
                            });
                            break;
case 'ContactType':     
mydatamodel = kendo.data.Model.define({
                                id: "__KEY",
                                fields: {
                                __KEY: { type: "string" },
                                __STAMP: { type: "number" },
                                ID: { editable: false, nullable: true },                                                                
                                name: { type: "string" }                                
                                }                               
                            });
                            break;
};

return new mydatamodel();
};

And use your creator function like this:

var mymodel = GetModel("Contact");

EDIT

Or use you code like this:

var mymodel = new (GetModel("Contact"))();