The XMLHttpRequest
property responseType
is an enumerated string value specifying the type of data contained in the response.
It also lets the author change the response type. If an empty string is set as the value of responseType
, the default value of text
is used.
A string which specifies what type of data the response contains. It can take the following values:
""
-
An empty responseType
string is the same as "text"
, the default type.
"arraybuffer"
-
The response
is a JavaScript ArrayBuffer
containing binary data.
"blob"
-
The response
is a Blob
object containing the binary data.
"document"
-
The response
is an HTML Document
or XML XMLDocument
, as appropriate based on the MIME type of the received data. See HTML in XMLHttpRequest to learn more about using XHR to fetch HTML content.
"json"
-
The response
is a JavaScript object created by parsing the contents of received data as JSON.
"text"
-
The response
is a text in a string.
Note: When setting responseType
to a particular value, the author should make sure that the server is actually sending a response compatible with that format. If the server returns data that is not compatible with the responseType
that was set, the value of response
will be null
.
You cannot change the value of responseType
in a synchronous XMLHttpRequest
except when the request belongs to a Worker
. This restriction is designed in part to help ensure that synchronous operations aren't used for large transactions that block the browser's main thread, thereby bogging down the user experience.
XHR requests are asynchronous by default; they are only placed in synchronous mode by passing false
as the value of the optional async
parameter when calling open()
.
Attempts to set the value of responseType
to document
are ignored in a Worker
.