HTTP Methods

HTTP (Hypertext Transfer Protocol) is created to provide communication between clients and the server. It works as request and answer.

There are two basic HTTP methods: GET and POST.

GET Method

The GET method of HTTP requests data from a specified source. GET requests can be cached and remain in the browser history. It can also be bookmarked.

It should never be used while working on sensitive data. GET requests have length restrictions, and they should be used only to get data.

The query strings (name/value pairs) is sent in the GET request's URL.

The code will look like this:

<form  method="get">
     First name: <input type="text" placeholder="Your name"><br/>
     <input type="submit" value="Submit">
</form>

POST Method

The POST method submits data to be processed to a specified source. As opposed to the GET method, POST requests are never cached and do not stay in the browser history, and we cannot bookmark them. Moreover, POST requests have no data length restrictions.

The query strings (name/value pairs) is sent in the POST request's HTTP Message body.

The code will look like this:

<form  method="post">
     First name: <input type="text" placeholder="Your name"><br/>
     <input type="submit" value="Submit">
</form>

Comparison of GET and POST Methods

GET POST
Back button/Reload Harmless It means that the data will be resubmitted. The browser must warn that the data will be re-submitted in this case.
Can be Bookmarked Yes No
Can be cached Yes No
Encoding Type application/x-www-form-urlencoded application/x-www-form-urlencoded or multipart/form-data
History Remains in the browser history. Doesn't remain in the browser history.
Data Length Restrictions While sending data, GET method adds the data to the URL; and the URL length is limited (maximum URL length is 2048 characters). Doesn't have restrictions.
Data Type Restriction Only ASCII characters allowed. Doesn't have restrictions. Binary data is also allowed.
Security It is less secured than POST as data sent is a part of URL. POST is a little safer than GET as it is not remaining in the browser history or web server logs.
Visibility Data is visible to everyone in the URL. Doesn't show data in the URL.

Other HTTP Request Methods

Beside GET and POST methods, there are some other methods. See them below:

Method Description
HEAD It is same with GET method but it returns only HTTP readers, no document body.
OPTIONS It returns HTTP methods which are supported by the server.
CONNECT It converts request connection to a transparent TCP/IP tunnel.

Put Method

PUT method is mostly used for **update** abilities, in other words, with this method we put a popular resource URL with the request body which contains the representation of the original resource that has been recently updated. This method can also be used for generating a resource, when the resource ID chooses the client, not the server.

Take into account, that PUT isn’t considered as a safe method, because even if it creates or changes state on the server, it is idempotent. This means, that if you create or modify the resource with this method, and then make the same call for the second time, the resource will be still there with the same state as it did with the first one.

The example below requests the server to save the given entity-body in method.py at the root of the server:

PUT /method.py HTTP/1.1
User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)
Host: www.w3docs.com
Accept-Language: en-us
Connection: Keep-Alive
Content-type: text/html
Content-Length: 182

After storing the given entity-bode in the file, the server will send the following response:

HTTP/1.1 201 Created
Date: Tue, 13 Dec 2019 14:53:57 GMT
Server: Apache/2.2.14 (Win32)
Content-type: text/html
Content-length: 30
Connection: Closed

Patch Method

PATCH method is mostly used for **modify** abilities. It doesn’t need the whole resource, it only needs to contain the changes to the resource. This method is neither idempotent, nor safe. Collisions between two PATCH requests can be very dangerous, as some patch formats need an operation from a popular base-point, otherwise the resource will be corrupted.

Delete Method

As you can guess, this method is used to **delete** a resource that is identified by a URL. This method is idempotent, too. In the case of deleting a resource it will be removed. And if you call for DELETE for multiple times, the result will be the same - the resource will be removed.

The example below, requests the server to delete the method.py file, at the root of the server:

DELETE /method.ry HTTP/1.1
User-Agent: Mozilla/4.0 (compatible; MSIE5.01; Windows NT)
Host: www.w3docs.com
Accept-Language: en-us
Connection: Keep-Alive

After deleting the file, the server will send the following response:

HTTP/1.1 200 OK
Date: Tue, 13 Dec 2019 14:53:57 GMT
Server: Apache/2.2.14 (Win32)
Content-type: text/html
Content-length: 30
Connection: Closed



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