Add ein-query.el

ein-query.el

@@ -0,0 +1,132 @@
+;;; ein-query.el --- jQuery like interface on to of url-retrieve
+
+;; Copyright (C) 2012- Takafumi Arakaki
+
+;; Author: Takafumi Arakaki
+
+;; This file is NOT part of GNU Emacs.
+
+;; ein-query.el is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; ein-query.el is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with ein-query.el.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(eval-when-compile (require 'cl))
+(require 'url)
+
+(require 'ein-utils)
+(require 'ein-log)
+
+(defun ein:safe-funcall-packed (packed &rest args)
+  (when packed
+    (ein:log-ignore-errors (apply #'ein:funcall-packed packed args))))
+
+(defun* ein:query-ajax (url &rest settings
+                            &key
+                            (cache t)
+                            (type "GET")
+                            (data nil)
+                            (headers nil)
+                            (success nil)
+                            (error nil)
+                            (timeout nil)
+                            (status-code nil))
+  "Mimic `$.ajax'.
+
+:CACHE       (nil/t) : append time-stamp to URL so the URL is always loaded.
+:TYPE       (string) : sets `url-request-method'
+:DATA       (string) : sets `url-request-data'
+:HEADERS     (alist) : sets `url-request-extra-headers'
+:SUCCESS      (cons) : called on success
+:ERROR        (cons) : called on error
+:TIMEOUT    (number) : timeout in millisecond
+:STATUS-CODE (alist) : map status code (int) to callback (cons)
+
+* Callback functions
+
+All callbacks must be given as `cons' where car is a FUNCTION and
+cdr is its first ARGUMENT.  It is analogous of `$.proxy'.  Call
+signature is like this:
+    \(FUNCTION ARGUMENT [other callback specific arguments])
+
+The second note is that the callback FUNCTION must be defined
+using `defun*' with `&key' and `&allow-other-keys' to ignore
+missing/extra arguments as some callback (namely :ERROR) changes
+arguments to be passed, depending on situation.
+
+Finally, note that callback FUNCTION is executed on the process
+buffer, meaning that response data is on the current buffer when
+the FUNCTION is called.  There is no `:data' argument for
+FUNCTION so it must be fetched from the buffer.
+
+* :ERROR callback
+
+:SYMBOL-STATUS (`error'/`timeout') : analogous of `textStatus'
+:STATUS                     (list) : see `url-retrieve'
+
+The :SUCCESS callback also takes the :STATUS argument.
+
+* See also: http://api.jquery.com/jQuery.ajax/"
+  (unless cache
+    (setq url (ein:url-no-cache url)))
+  (let* ((url-request-extra-headers headers)
+         (url-request-method type)
+         (url-request-data data)
+         (buffer (url-retrieve url #'ein:query-ajax-callback settings)))
+    (when timeout
+      (run-at-time (/ timeout 1000.0) nil
+                   #'ein:query-ajax-timeout-callback
+                   (cons buffer settings)))
+    buffer))
+
+(defun* ein:query-ajax-callback (status &key
+                                        (headers nil)
+                                        (success nil)
+                                        (error nil)
+                                        (timeout nil)
+                                        (status-code nil)
+                                        &allow-other-keys)
+  (declare (special url-http-response-status
+                    url-http-method))
+  (unwind-protect
+      (progn
+        (ein:log 'debug "EIN:QUERY-AJAX-CALLBACK")
+        (ein:log 'debug "status = %S" status)
+        (ein:log 'debug "url-http-response-status = %s"
+                 url-http-response-status)
+        (ein:log 'debug "(buffer-string) =\n%s" (buffer-string))
+
+        (apply #'ein:safe-funcall-packed
+               (if (plist-get status :error)
+                   (list error :symbol-status 'error :status status)
+                 (list success :status status)))
+        (ein:aif (assq url-http-response-status status-code)
+            (ein:safe-funcall-packed (cdr it))))
+    (kill-buffer)))
+
+(defun* ein:query-ajax-timeout-callback (buffer &key
+                                                (error nil)
+                                                &allow-other-keys)
+  (with-current-buffer buffer
+    (ein:safe-funcall-packed error :symbol-status 'timeout))
+  (let ((proc (process-buffer buffer)))
+    (kill-process proc)
+    (kill-buffer buffer)))
+
+(provide 'ein-query)
+
+;;; ein-query.el ends here