Merge pull request #95 from vermiculus/commenting

Commenting

5 files changed, 106 insertions, 9 deletions

diff --git a/sx-interaction.el b/sx-interaction.el
index a9203bd..404fb56 100644
--- a/sx-interaction.el
+++ b/sx-interaction.el
@@ -106,5 +106,85 @@ changes."
       ;; Display the changes in `data'.
       (sx--maybe-update-display))))
 
+
+;;; Commenting
+(defun sx-comment (data text)
+  "Post a comment on DATA given by TEXT.
+DATA can be a question, an answer, or a comment. Interactively,
+it is guessed from context at point.
+If DATA is a comment, the comment is posted as a reply to it.
+
+TEXT is a string. Interactively, it is read from the minibufer."
+  (interactive
+   (list (sx--data-here) 'query))
+  (sx-assoc-let data
+    ;; Get the comment text
+    (when (eq text 'query)
+      (setq text (read-string
+                  "Comment text: "
+                  (when .comment_id
+                    (sx--user-@name .owner))))
+      (while (< (string-width text) 15)
+        (setq text (read-string "Comment text (at least 15 characters): " text))))
+    ;; If non-interactive, `text' could be anything.
+    (unless (stringp text)
+      (error "Comment body must be a string"))
+    ;; And post
+    (let ((result
+           (sx-method-call 'posts
+             :id (or .post_id .answer_id .question_id)
+             :submethod "comments/add"
+             :auth 'warn
+             :url-method "POST"
+             :filter sx-browse-filter
+             :site .site
+             :keywords `((body ,text)))))
+      ;; The api returns the new DATA.
+      (when (> (length result) 0)
+        (sx--add-comment-to-object
+         (elt result 0)
+         (if .post_id
+             (sx--get-post .post_type .site .post_id)
+           data))
+        ;; Display the changes in `data'.
+        (sx--maybe-update-display)))))
+
+(defun sx--get-post (type site id)
+  "Find in the database a post identified by TYPE, SITE and ID.
+TYPE is `question' or `answer'. 
+SITE is a string.
+ID is an integer."
+  (let ((db (cons sx-question-mode--data
+                  sx-question-list--dataset)))
+    (setq db
+          (cond 
+           ((string= type "question") db)
+           ((string= type "answer")
+            (apply #'cl-map 'list #'identity
+                   (mapcar (lambda (x) (cdr (assoc 'answers x))) db)))))
+    (car (cl-member-if
+          (lambda (x) (sx-assoc-let x
+                   (and (equal (or .answer_id .question_id) id)
+                        (equal .site site))))
+          db))))
+
+(defun sx--add-comment-to-object (comment object)
+  "Add COMMENT to OBJECT's `comments' property.
+OBJECT can be a question or an answer."
+  (let ((com-cell (assoc 'comments object))
+        (count-cell (assoc 'comment_count object)))
+    (if com-cell
+        (progn
+          (setcdr
+           com-cell
+           (apply #'vector
+                  (append
+                   (cl-map 'list #'identity
+                           (cdr com-cell))
+                   (list comment)))))
+      ;; No previous comments, add it manually.
+      (setcdr object (cons (car object) (cdr object)))
+      (setcar object `(comments . [,comment])))))
+
 (provide 'sx-interaction)
 ;;; sx-interaction.el ends here
diff --git a/sx-question-list.el b/sx-question-list.el
index 4d7681b..2965ede 100644
--- a/sx-question-list.el
+++ b/sx-question-list.el
@@ -427,8 +427,10 @@ This does not update `sx-question-mode--window'."
   (forward-line -1)
   (when (functionp sx-question-list--next-page-function)
     ;; Try to get more questions
-    (let ((list (funcall sx-question-list--next-page-function
-                  (1+ sx-question-list--pages-so-far))))
+    (let ((list
+           (cl-map 'list #'identity
+                   (funcall sx-question-list--next-page-function
+                     (1+ sx-question-list--pages-so-far)))))
       (if (null list)
           (message "No further questions.")
         ;; If it worked, increment the variable.
@@ -436,7 +438,8 @@ This does not update `sx-question-mode--window'."
         ;; And update the dataset.
         ;; @TODO: Check for duplicates.
         (setq sx-question-list--dataset
-              (append sx-question-list--dataset list))
+              (append sx-question-list--dataset
+                      list))
         (sx-question-list-refresh 'redisplay 'no-update)
         (forward-line 1)))))
 
diff --git a/sx-question-mode.el b/sx-question-mode.el
index f1a8cc0..70b8866 100644
--- a/sx-question-mode.el
+++ b/sx-question-mode.el
@@ -499,11 +499,12 @@ Prefix argument N moves N sections down or up."
         (unless (and (overlayp ov)
                      (overlay-get ov 'invisible))
           (cl-decf count)))))
-  (when sx-question-mode-recenter-line
-    (let ((ov (car-safe (sx-question-mode--section-overlays-at (line-end-position)))))
-      (when (and (overlayp ov) (> (overlay-end ov) (window-end)))
-        (recenter sx-question-mode-recenter-line))))
-  (sx-message-help-echo))
+  (when (equal (selected-window) (get-buffer-window))
+    (when sx-question-mode-recenter-line
+      (let ((ov (car-safe (sx-question-mode--section-overlays-at (line-end-position)))))
+        (when (and (overlayp ov) (> (overlay-end ov) (window-end)))
+          (recenter sx-question-mode-recenter-line))))
+    (sx-message-help-echo)))
 
 (defun sx-question-mode-previous-section (&optional n)
   "Move down to previous section (question or answer) of this buffer.
@@ -571,6 +572,7 @@ Letters do not insert themselves; instead, they are commands.
  `(("n" sx-question-mode-next-section)
    ("p" sx-question-mode-previous-section)
    ("g" sx-question-mode-refresh)
+   ("c" sx-comment)
    ("v" sx-visit)
    ("u" sx-toggle-upvote)
    ("d" sx-toggle-downvote)
diff --git a/sx-question.el b/sx-question.el
index de07c94..a7aadb2 100644
--- a/sx-question.el
+++ b/sx-question.el
@@ -43,7 +43,7 @@ property.
   "Query SITE for a QUESTION-ID and return it.
 If QUESTION-ID doesn't exist on SITE, raise an error."
   (let ((res (sx-method-call 'questions
-               :id id
+               :id question-id
                :site site
                :auth t
                :filter sx-browse-filter)))
diff --git a/sx.el b/sx.el
index e5f81a4..d4c3ac2 100644
--- a/sx.el
+++ b/sx.el
@@ -56,6 +56,7 @@
      question.link
      question.upvoted
      question.downvoted
+     question.question_id
      user.display_name
      comment.owner
      comment.body_markdown
@@ -65,6 +66,10 @@
      comment.creation_date
      comment.upvoted
      comment.score
+     comment.post_type
+     comment.post_id
+     comment.comment_id
+     answer.answer_id
      answer.last_editor
      answer.link
      answer.owner
@@ -193,6 +198,13 @@ Return the result of BODY."
      (add-text-properties p (point) ,properties)
      result))
 
+(defun sx--user-@name (user)
+  "Get the `display_name' of USER prepended with @."
+  (sx-assoc-let user
+    (when (stringp .display_name)
+      (concat "@" .display_name))))
+
+
 ;;; Assoc-let
 (defun sx--site (data)
   "Get the site in which DATA belongs.