WebApi: WebApi Patch Update Using FromBody Parameter in WebApi Using MVC4 Template

Sachin Kalia

MVC 4MVC4 TemplateFromBody parameter in WebApiWebApi Patch Update

11 Comments

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sibadutta Nayak6y ago
It not a complete solution.
prideaux906y ago
This part does not make sense, you are talking about PATCH, suddenly you mention POST. Note: FromBody contains entire request body of the POST request, not a piece of the body, is bound to a parameter. For this reason, you cannot have multiple parameters with the FromBody attribute in an action method. So are you saying, for PATCH is it ok (or not?) to "have multiple parameters with the FromBody attribute in an action method."
Joginder Banger9y ago
As per @sachin Kalia article, patch method update the value partially, but i have one question regarding this is internally patch use the POST or PUT??
Gaurav Kumar Arora11y ago
Does this mean if I have an employee object and I want to update only firstname or lastname then Patch is better. But, what about if one time I need to update FirstName and another time LastName then in this case do I need to create to Resources one for firstname and another for lastname?
Gaurav Kumar Arora11y ago
Thanks Sachin Kalia for clarifying. Its good to know that
Sachin Kalia11y ago
The HTTP methods PATCH can be used to update partial resources. For instance, when you only need to update one field of the resource.most of the time you want to update one or two values in a resource, not everything, so the PUT method is probably not the right solution for partial update.In the example given above if you send an object like Employee keeps 20-25 values than PUT sounds good ,however if i just want to update a single values than as per the HTTP guideline Patch is better option.Kindly refer https://tools.ietf.org/html/rfc5789#page-2
- pramod Singh8y ago
  You said that "PUT method is probably not the right solution for partial update".but could you describe the reason why patch is best than put.but we can perform same thing by put and patch both.do you have any concrete reason for it.i read theory everywhere but not any concrete reason
Gaurav Kumar Arora11y ago
Congrats Sachin Kalia for article of the day. I am curious to know or might be you did not clear the same in your post, why HTTPPATCH, when I can do the same thing using HTTPPUT. I ran the diffler and other tools which gives me the same thing payload etc even they are traversing same on the wire.
Sachin Kalia11y ago
Thanks Dinesh Beniwal Bhai G :)
Dinesh Beniwal11y ago
Again Congrats Sachin, Article of the day on ASP.NET
Atul Rawat11y ago
nice article

In this article, I’ll share my thoughts on Patch update using FromBody in WebApi Configuration over Convention. I’ve also used Fiddler in this article. I hope you are familiar with the Web Proxy Tool Fiddler.

Kindly visit this link to learn more about Configuration over Convention in the WebApi.

Configuration Over Convention in WebApi Using MVC4 Template

HTTP POST can support partial updates to a resource. But there is a separate PATCH method. This new HTTP method, PATCH, modifies an existing HTTP resource. The call to the Patch method is sufficient to partially update the corresponding properties of the Employee object in the list. For example, the request will update only the LastName property of the employee with the ID of 002 to “Thakur”, but in order to issue a PATCH request, you will need to use a tool like Fiddler.

Kindly have a look at Fiddler to understand how it looks like in the following image.

Let’s create a sample application and do this step-by-step.

Step 1: Let’s first create a sample web application and using ASP.NET MVC 4 Web Application and name it as you choose; I used WebApiDemo as shown in the following image:

Step 2: Click OK and choose Web API from the templates shown in the wizard window.

Step 3: You’ll find the application structure as shown below at first sight.

Step 4: Right-click the Controllers folder in the Solution Explorer of Visual Studio. Select "Add" ➤"Controller" and provide a name of EmployeesController for the controller. Leave the option Empty API Controller selected in the Template dropdown and click "Add", as shown in the figure below. Notice that the generated controller class inherits from ApiController, a class that is part of the ASP.NET Web API framework. Kindly add the following code into the EmployeesController class.

public static IList<Employee> listEmp = new List<Employee>()
{
new Employee()
{
ID =001, FirstName="Sachin", LastName="Kalia"
},
new Employee()
{
ID =002, FirstName="Dhnanjay" ,LastName="Kumar"
},
new Employee()
{
ID =003, FirstName="Ravish", LastName="Sindhwani"
},
new Employee()
{
ID =004, FirstName="Amit" ,LastName="Chaudhary"
},
};

Step 5: Right-click the Models folder in the Solution Explorer of Visual Studio. Select "Add" -> "Class" to add a new class with a name of Employee.

After creating the Employee class, kindly add the following code into this class.

public class Employee
{
public string ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}

Now I’ve created a method named UpdateDetailsViaPatch, that follows the convention based (starts with Get, PUT, POST, Delete and PATCH) approach to call methods of WebApi with [FromBody] as the action parameter.

Note: FromBody contains entire request body of the POST request, not a piece of the body, is bound to a parameter. For this reason, you cannot have multiple parameters with the FromBody attribute in an action method.

Press F5 and run your application; it will show the following image:

Great WebApi is up and running.

This is the request that we’ve set into Fiddler as depicted below:

Kindly paste this URL (http://localhost:57888/api/Employees/002 ) into Fiddler and click on Execute, it will reach into your code segment. Where you’ve set a debugging breakpoint. This is the convention based approach (the method starts with the HTTP Verb PATCH).

Press F5 again and see the result as shown below in the image.

To verify that it has only updated the LastName of Dhnanjay, paste this URL (http://localhost:57888/api/employees/002) in the browser and see the result as shown below in the image.

Conclusion

In this article, we looked into the Patch update using FromBody.