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Form submission: event and method submit

The submit event triggers when the form is submitted, it is usually used to validate the form before sending it to the server or to abort the submission and process it in JavaScript.

The method form.submit() allows to initiate form sending from JavaScript. We can use it to dynamically create and send our own forms to server.

Let's see more details of them.

Event: submit

There are two main ways to submit a form:

  1. The first -- to click <input type="submit"> or <input type="image">.
  2. The second -- press key:Enter on an input field.

Both actions lead to submit event on the form. The handler can check the data, and if there are errors, show them and call event.preventDefault(), then the form won't be sent to the server.

In the form below:

  1. Go into the text field and press key:Enter.
  2. Click <input type="submit">.

Both actions show alert and the form is not sent anywhere due to return false:

<form onsubmit="alert('submit!');return false">
  First: Enter in the input field <input type="text" value="text"><br>
  Second: Click "submit": <input type="submit" value="Submit">

````smart header="Relation between submit and `click`" When a form is sent using `key:Enter` on an input field, a `click` event triggers on the ``.

That's rather funny, because there was no click at all.

Here's the demo:

<form onsubmit="return false">
 <input type="text" size="30" value="Focus here and press enter">
 <input type="submit" value="Submit" *!*onclick="alert('click')"*/!*>

## Method: submit

To submit a form to the server manually, we can call `form.submit()`.

Then the `submit` event is not generated. It is assumed that if the programmer calls `form.submit()`, then the script already did all related processing.

Sometimes that's used to manually create and send a form, like this:

```js run
let form = document.createElement('form');
form.action = '';
form.method = 'GET';

form.innerHTML = '<input name="q" value="test">';

// the form must be in the document to submit it