[Ebib-users] searching across multiple real databases

[Robbie M. <ro...@ac...>]

Hello Joost and list

This posting relates to searching across multiple
databases.  Unless I have misread the
documentation badly (always a possibility), basic
emacs-based searches and advanced searching
(resulting in virtual databases) are only
possible within the one database.  Is this
correct?

I would like to work across six BibTeX files.

It so, there are two possible fixes: concatenate
the BibTeX files beforehand.  Or offer users a
'super' database, a union of the existing real
databases.  Call it super, logical, or virtual, as
you like.  In fact, 'logical' has some merits.

Anyway, I hacked a bit of 'ebib.el' to try and get
something happening.  The following patch FAILS to
work, but did run.  You should get the drift,
anyhow.

My questions are two-fold:

   * is this functionality needed ?
   * is this functionality possible ?

It yes to both, I may go on hacking.  Else, I will
give up and simply run 'cat' on my BibTeX files to
produce on single real (physical) database and
leave it at that.

many thanks in advance, Robbie

CAUTION: patch is also hand-edited so may not take

--- ebib.el.orig        2012-08-18 00:36:40.663700389 +0200
+++ ebib.el             2012-08-18 04:33:38.433636738 +0200
@@ -1518,6 +1518,7 @@
 (ebib-key index "&" ebib-virtual-db-and)
 (ebib-key index "|" ebib-virtual-db-or)
 (ebib-key index "~" ebib-virtual-db-not)
+(ebib-key index "+" ebib-virtual-db-union)
 (ebib-key index ";" ebib-prefix-map)
 (ebib-key index "a" ebib-add-entry)
 (ebib-key index "b" ebib-index-scroll-down)
@@ -1746,13 +1747,16 @@
     (message "%s found! Press `l' to check Ebib log buffer." (nth
ebib-log-error '("Warnings" "Errors"))))
   (ebib-log 'log ""))

-(defun ebib-merge-bibtex-file ()
+(defun ebib-merge-bibtex-file (bibfile)
   "Merges a BibTeX file into the database."
   (interactive)
-  (unless (edb-virtual ebib-cur-db)
+; (unless (edb-virtual ebib-cur-db)
+  (unless nil                                ; robbie 18-Aug-2012
     (if (not ebib-cur-db)
         (error "No database loaded. Use `o' to open a database")
-      (let ((file (read-file-name "File to merge: ")))
+      (let ((file bibfile))                  ; could well be 'nil'
+        (unless file
+          (setq file  (read-file-name "File to merge: ")))
         (setq ebib-log-error nil)       ; we haven't found any errors
         (ebib-log 'log "%s: Merging file %s" (format-time-string
"%d-%b-%Y: %H:%M:%S") (edb-filename ebib-cur-db))
         (with-temp-buffer
@@ -2889,6 +2893,51 @@
           (ebib-log 'message "invoking: %s %s" "find-file" file-full-path)
           (find-file file-full-path))))))

+; robbie 18-Aug-2012
+; from 'ebib-virtual-db-and'
+(defun ebib-virtual-db-union (arg)
+  "Combine open databased into a single virtual database.
+If the current database is a virtual database already,
+ignore the command."
+  (interactive "p")                          ; cannot think of a reason
for this
+  (ebib-log 'message "creating virtual union database")
+
+  (let* ((dbname  "union"                        )
+         (new-db  (ebib-create-new-database nil) )     ; create new
database, adds to census
+         (count   0                              ))
+
+    (setf (edb-virtual     new-db) t)                            ; mark
virtual, 't' also works
+    (setf (edb-filename    new-db) nil)
+    (setf (edb-name        new-db) (concat "V:" dbname))
+    (setf (edb-modified    new-db) nil)
+    (setf (edb-make-backup new-db) nil)
+
+    ;; loop non-virtual databases
+    (dolist (db ebib-databases)
+      (ebib-execute-when
+        ((database)                          ; for some reason (real-db)
did not seem to take
+         (setq ebib-cur-db db)               ; change focus
+         (unless (edb-virtual db)            ; skip virtual databases
+           (let ((ebib-merge-bibtex-filename (edb-filename ebib-cur-db) ))
+             (ebib-merge-bibtex-file ebib-merge-bibtex-filename)
+             (incf count)
+             (ebib-log 'message "current database %S"   ebib-cur-db)
+             (ebib-log 'message "current filename %s\n" (prin1-to-string
ebib-merge-bibtex-filename))
+             )))))
+    (ebib-log 'message "traversed %d databases\n" count)
+
+    ;; file virtual database
+    (ebib-fill-entry-buffer)                 ; fill entry buffer
+    (ebib-fill-index-buffer)                 ; fill index buffer
+    ))
+
+; 'ebib-merge-bibtex-file'
+; 'ebib-save-all-databases' uses 'mapc'
+
 (defun ebib-virtual-db-and (not)
   "Filters entries into a virtual database.
 If the current database is a virtual database already, perform a

---
Robbie Morrison
PhD student -- policy-oriented energy system simulation
Technical University of Berlin (TU-Berlin), Germany
University email (redirected) : mor...@ie...
Webmail (preferred)           : ro...@ac...
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