Request: formData() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Note: This feature is available in Web Workers.
The formData() method of the Request interface
reads the request body and returns it as a promise that resolves with a FormData object.
Syntax
js
formData()
Parameters
None.
Return value
Exceptions
TypeError-
Thrown for one of the following reasons:
- The request body is disturbed or locked.
- There was an error decoding the body content (for example, because the
Content-Encodingheader is incorrect). - The MIME type of the body cannot be determined from the
Content-Typeheaders included in the request, or is notapplication/x-www-form-urlencodedormultipart/form-data. - The body cannot be parsed as a
FormDataobject.
Examples
js
const formData = new FormData();
const fileField = document.querySelector('input[type="file"]');
formData.append("username", "abc123");
formData.append("avatar", fileField.files[0]);
const request = new Request("/myEndpoint", {
method: "POST",
body: formData,
});
request.formData().then((data) => {
// do something with the formdata sent in the request
});
Specifications
| Specification |
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| Fetch # ref-for-dom-body-formdata① |
Browser compatibility
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Legend
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- Full support
- Full support
- Partial support
- Partial support
- Has more compatibility info.