What is the formmethod attribute in HTML5?

The formmethod attribute in HTML5 specifies the HTTP method for a button's form submission, overriding the form's method attribute; 1. It applies to and <input type="submit"> elements; 2. Accepted values include get and post, with potential support for put or delete via spoofing; 3. It overrides the parent

’s method only for that button; 4. It enables different submission methods within the same form, such as using POST for “Save” and GET for “Preview”; 5. It works only on submit buttons and requires association with a form; 6. Data is URL-encoded in the URL for get and sent in the request body for post; thus, formmethod allows precise control over submission methods per button without JavaScript or multiple forms.

The formmethod attribute in HTML5 is used to specify the HTTP method (such as get or post) that should be used when submitting a form from a button or input element. It overrides the method defined in the <form></form> element’s method attribute, but only for that specific button's submission.

This attribute is typically used with <button></button> or <input type="submit"> elements that are inside a form or associated with one.

Key Points:

• Applies to: <button></button> and <input type="submit">
• Values: get or post (most common), though other HTTP methods like put or delete may be supported in specific contexts via spoofing.
• Overrides: The method attribute of the parent <form></form>
• Use case: Allows different buttons in the same form to submit data using different methods.

Example:

<form action="/submit" method="get">
  <input type="text" name="username" />

  <!-- This button will use POST instead of GET -->
  <button type="submit" formmethod="post">Submit with POST</button>

  <!-- This button uses the form's default GET method -->
  <button type="submit">Submit with GET</button>
</form>

In this example:

• Clicking the first button sends the form data via POST to /submit, even though the form's default method is get.
• Clicking the second button uses the form’s default GET method.

Common Use Cases:

• A form with both "Save Draft" (POST) and "Preview" (GET) buttons.
• Admin interfaces where one button deletes (using post with a hidden _method field simulating delete) and another updates (using post).

Notes:

• The formmethod attribute only works on submit buttons.
• It must be used in conjunction with a form (either inside it or via the form attribute).
• For get, form data is appended to the URL; for post, it's sent in the request body.

Basically, formmethod gives you fine-grained control over how individual buttons submit a form, without needing multiple forms or JavaScript.

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