Emacs Request

request.el -- an elisp HTTP library

Uses curl as its backend or Emacs's native url.el library if curl is not found.

The default encoding for requests is utf-8. Please explicitly specify :encoding 'binary for binary data.

Install

As described in Getting started, ensure melpa's whereabouts in init.el or .emacs:

(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/"))

Then

M-x package-refresh-contents RET
M-x package-install RET request RET

Alternatively, directly clone this repo and make install.

Examples

GET:

(request "http://httpbin.org/get"
  :params '(("key" . "value") ("key2" . "value2"))
  :parser 'json-read
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'args data)))))

POST:

(request "http://httpbin.org/post"
  :type "POST"
  :data '(("key" . "value") ("key2" . "value2"))
  ;; :data "key=value&key2=value2"  ;; this is equivalent
  :parser 'json-read
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'form data)))))

Block until completion:

(request "http://httpbin.org/get"
  :sync t
  :complete (cl-function
             (lambda (&key response &allow-other-keys)
               (message "Done: %s" (request-response-status-code response)))))

Curl authentication:

(request "http://httpbin.org/get"
  :auth "digest" ;; or "basic", "anyauth", etc., which see curl(1)
  :complete (cl-function
             (lambda (&key response &allow-other-keys)
               (message "Done: %s" (request-response-status-code response)))))

Request binary data:

(request "http://httpbin.org/get"
  :encoding 'binary
  :complete (cl-function
             (lambda (&key response &allow-other-keys)
               (message "Done: %s" (request-response-status-code response)))))

POST file (WARNING: it will send the contents of the current buffer!):

(request "http://httpbin.org/post"
  :type "POST"
  :files `(("current buffer" . ,(current-buffer)))
  :parser 'json-read
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'files data)))))

Rich callback dispatch (like jQuery.ajax):

(request "http://httpbin.org/status/418"
  ;; "http://httpbin.org/status/200"  ;; success callback will be called.
  ;; "http://httpbin.org/status/400"  ;; you will see "Got 400."
  :parser 'buffer-string
  :success
  (cl-function (lambda (&key data &allow-other-keys)
                 (when data
                   (with-current-buffer (get-buffer-create "*request demo*")
                     (erase-buffer)
                     (insert data)
                     (pop-to-buffer (current-buffer))))))
  :error
  (cl-function (lambda (&rest args &key error-thrown &allow-other-keys)
                 (message "Got error: %S" error-thrown)))
  :complete (lambda (&rest _) (message "Finished!"))
  :status-code '((400 . (lambda (&rest _) (message "Got 400.")))
                 (418 . (lambda (&rest _) (message "Got 418.")))))

Flexible PARSER option:

(request "https://github.com/tkf/emacs-request/commits/master.atom"
  ;; Parse XML in response body:
  :parser (lambda () (libxml-parse-xml-region (point) (point-max)))
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              ;; Just don't look at this function....
              (let ((get (lambda (node &rest names)
                           (if names
                               (apply get
                                      (first (xml-get-children
                                              node (car names)))
                                      (cdr names))
                             (first (xml-node-children node))))))
                (message "Latest commit: %s (by %s)"
                         (funcall get data 'entry 'title)
                         (funcall get data 'entry 'author 'name))))))

PUT JSON data:

(request "http://httpbin.org/put"
  :type "PUT"
  :data (json-encode '(("key" . "value") ("key2" . "value2")))
  :headers '(("Content-Type" . "application/json"))
  :parser 'json-read
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'json data)))))

PUT JSON data including non-ascii strings:

(request "http://httpbin.org/put"
  :type "PUT"
  :data (json-encode '(("key" . "1") ("key2" . "2")))
  :headers '(("Content-Type" . "application/json"))
  :parser 'json-read
  :encoding 'utf-8
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'json data)))))

Another PUT JSON example (nested JSON using alist structure, how to represent a boolean & how to selectively evaluate lisp):

;; (1) Prepend alist structure with a backtick (`) rather than single quote (')
;;     to allow elisp evaluation of selected elements prefixed with a comma (,)
;; (2) This value is expected as a boolean so use the nil / t elisp alist denotation
;; (3) The function will be evaluated as it has been prefixed with a comma (,)
(request "http://httpbin.org/put"
  :type "PUT"
  :data (json-encode `(("jsonArray" . (("item1" . "value 1") ;; (1)
                                       ("item2" . t)         ;; (2)
                                       ("item3" . ,(your-custom-elisp-function)))))) ;; (3)
  :headers '(("Content-Type" . "application/json"))
  :parser 'json-read
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "I sent: %S" (assoc-default 'json data)))))

GET with Unix domain socket data:

(request "http:/hello.txt"
  :unix-socket "/tmp/app.sock"
  :parser (lambda () (buffer-string))
  :success (cl-function
            (lambda (&key data &allow-other-keys)
              (message "Got: %s" data))))

Legacy documentation

• Github Pages <https://tkf.github.io/emacs-request/>