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    Use HTTP GET & HEAD Methods

    Pete JohansonPete Johanson

    The HTTP GET & HEAD methods are used to retrieve information about a resource. The GET method will retrieve the metadata about the resource, encoded in the HTTP headers, as well as a representation of the resource itself in the message body (e.g. a JSON document with fields that describe a user). The HEAD method behaves like GET, but only retrieves the status and headers; this can be useful when you need some metadata about a resource (e.g. the Last-Modification time), but don't want to waste time or bandwidth fetch the resource itself in the message body. Finally, we discuss the idempotent and safe natures of these HTTP methods.

    httpHTTP
    javascriptJavaScript
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    Transcript

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    00:00 The HTTP get method is used to retrieve a representation of a resource. Let's take a look at my user using the GitHub API. Here we can see the HTTP get has returned us a set of headers with metadata about this particular resource as well as the actual message body containing a representation of that resource, in this case, in JSON format.

    00:30 Much like get, the head HTTP method is used to retrieve a resource. Unlike get, the response will only include the HTTP headers containing the metadata about that resource and does not include the message body.

    00:47 This can be very useful if we need to only look up some metadata about a resource such as whether we have the latest version based on the e-tag or the last modified date of a certain resource and we don't want to waste the bandwidth or time retrieving the actual resource body.

    01:04 Both get and head are considered item potent methods which means that issuing multiple requests or just one request will have the exact same effect. I can issue several head requests of this resource, and there will be no changes made to the resource. The response will be the same.

    01:24 Much like being item potent, both get and head are also considered safe methods. That means that a user agent such as a browser can feel free to resubmit these requests when a user clicks the back button without prompting them or warning them that there may be some changes made as a result of issuing those requests.

    01:44 To summarize, both get and head will retrieve a resource. The main difference being get will also retrieve a representation of the resource in the body in addition to the header's return.

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