How to get org2blog to use .authinfo.gpg

Question

I have .authinfo.gpg set up and working as the authentication mechanism for ERC (with multiple IRC servers) and Gnus (with multiple IMAP servers) using the following in my config:

(require 'auth-source)

(setq
 auth-sources '(default
                 "secrets:session"
                 "secrets:Login"
                 "~/.authinfo.gpg"
                 "~/.authinfo"
                 "~/.netrc"
                 )
 epa-file-cache-passphrase-for-symmetric-encryption t)

My .authinfo.gpg includes entries like this (sanitized, naturally, and trimmed to just WordPress blog samples):

machine example.com login JohnDoe password "password" port http
machine example2.com login JohnDoeJr password "password2" port http

My org2blog config is:

(use-package org2blog
  :defer t
  :ensure t
  :config
  (require 'org2blog-autoloads)
  ;;  (org2blog/wp-use-sourcecode-shortcode ‘t)
  (setq
   org2blog/wp-confirm-post t
   org2blog/wp-blog-alist
   '(
     ("example1"
      :url "http://www.example.com/xmlrpc.php"
      :username ,(car (auth-source-user-and-password "example.com"))
      :password ,(cadr (auth-source-user-and-password "example.com"))
      :default-title "Hello, World!"
      :default-categories ("Uncategorized")
      )
     ("example2"
      :url "http://www.example2.com/xmlrpc.php"
      :username ,(car (auth-source-user-and-password "example2.com"))
      :password ,(cadr (auth-source-user-and-password "example2.com"))
      :default-title "Hello, World!"
      :default-categories ("Uncategorized")
      ))))

Using the above when logging into either, I get

xml-rpc-value-to-xml-list: Wrong type argument: stringp, \,

I've tried variations on the above but can't seem get get it to use .authinfo.gpg. The above error message is returned or I am prompted for my password.

I've used the following references to help me but so far to no avail:

• http://vxlabs.com/2014/05/25/emacs-24-with-prelude-org2blog-and-wordpress/
• http://thewanderingcoder.com/2015/02/publishing-from-org-mode-to-wordpress/
• https://github.com/punchagan/org2blog

I'm running:

• GNU Emacs 24.4.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8) of 2015-03-03 on lm-lvm-tpt430
• Org-mode version 8.2.10 (8.2.10-35-g19a7d6-elpaplus @
  /home/username/.emacs.d/elpa/org-plus-contrib-20150316/)
• org2blog 20150114.2301 from Melpa

Answer 1

According to punchagan, the org2blog maintainer:

You'll need to use a backtick instead of a quote (when setting org2blog/wp-blog-alist) to evaluate the expressions following a comma. See the 2nd example in the README.

(setq
 org2blog/wp-confirm-post t
 org2blog/wp-blog-alist
 `(
   ("example1"
    :url "http://www.example.com/xmlrpc.php"
    :username ,(car (auth-source-user-and-password "example.com"))
    :password ,(cadr (auth-source-user-and-password "example.com"))
    :default-title "Hello, World!"
    :default-categories ("Uncategorized")
    )
   ("example2"
    :url "http://www.example2.com/xmlrpc.php"
    :username ,(car (auth-source-user-and-password "example2.com"))
    :password ,(cadr (auth-source-user-and-password "example2.com"))
    :default-title "Hello, World!"
    :default-categories ("Uncategorized")
    )))

Oh, the backtick!