Merge Tool for Org-Mode

Table of Contents

Org-merge-driver Prototype

The program takes 2 modified versions of an Orgmode file and the original file, and tries to merge the changes into a single file. Any changes from the two files which cannot be merged properly are marked as a conflict, with the standard conflict markers.

The prototype only deals with one type of org-mode element: headings. An org-mode file is parsed into a tree of headings. All text below a heading but before the next heading is considered apart of the heading's text. A heading is identified by the text in the title (first line), or by an :ID: property if it has one.

The program then takes the parsed trees, and matches headings from one file to another. While it does this, it also detects new headings, removed headings, and headings moved underneath a new parent. For the prototype, I decided to regard headings as a un-ordered elements, so changing of position underneath a parent heading is not detected. This has also caused problems of accidentally reordering headings under a single parent in the output. This will be fixed for the final program.

Example Results 1

Here is an example run through with the program:

Ancestor:

* original heading
,- here is some text

File 1:

* original heading
,- here is some text
,- add some text in file 1
** New heading in file 1
,- more text
*** Sub new heading in file 1

File2:

#+TITLE: A New Title In File 2
* original heading
,- here is some text
** File 2 new sub heading
* A new heading in file 2
,- with some text

Program Stdout:

----------------
Node Change List:
----------------
Remove nodes: file 0
----------
Add nodes: file 1
(:title "New heading in file 1" :level 2 :parent-level 1 :id "" :text "- more text
")
(:title "Sub new heading in file 1" :level 3 :parent-level 2 :id "" :text "")
----------
Remove nodes: file 0
----------
Add nodes: file 2
(:title "File 2 new sub heading" :level 2 :parent-level 1 :id "" :text "")
(:title "A new heading in file 2" :level 1 :parent-level 0 :id "" :text "- with some text
")
----------------------
FILE : 0 NO_CHANGE
(:title "" :level 0 :no-parent :id "" :text "")
FILE : 2 NEW
(:title "A new heading in file 2" :level 1 :parent-level 0 :id "" :text "- with some text
")
FILE : 0 NO_CHANGE
(:title "original heading" :level 1 :parent-level 0 :id "" :text "- here is some text
")
FILE : 2 NEW
(:title "File 2 new sub heading" :level 2 :parent-level 1 :id "" :text "")
FILE : 1 NEW
(:title "New heading in file 1" :level 2 :parent-level 1 :id "" :text "- more text
")
FILE : 1 NEW
(:title "Sub new heading in file 1" :level 3 :parent-level 2 :id "" :text "")

The stdout can be confusing and misleading. It mostly shows what positional changes for the headings it has detected. It does not, however, show changes to the content under a heading.

Merged Document:

#+TITLE: A New Title In File 2
* A new heading in file 2
,- with some text
* original heading
,- here is some text
,- add some text in file 1
** File 2 new sub heading
** New heading in file 1
,- more text
*** Sub new heading in file 1

The file merged without any conflicts. This is because neither file updated the same heading. If File 1 had an additional top line that changed it to:

New file 1:

,- conflicting text in file 1
* original heading
,- here is some text
,- add some text in file 1
** New heading in file 1
,- more text
*** Sub new heading in file 1

Then the output has a conflict, and prints:

,<<<<<<< yours: t1-1.org
,- conflicting text in file 1
,=======
#+TITLE: A New Title In File 2
,>>>>>>> theirs: t1-2.org
* A new heading in file 2
,- with some text
* original heading
,- here is some text
,- add some text in file 1
** File 2 new sub heading
** New heading in file 1
,- more text
*** Sub new heading in file 1

Example Results 2

A more complicated example:

Ancestor:

* heading 1
** test heading
,:PROPERTIES:
,:ID: 100
,:END:
,- this is just a test
* heading 2
** test heading
,- this is a different heading

File 1:

* heading 1
** test heading
,- this is a different heading
* heading 3
** heading 4
*** test heading
,:PROPERTIES:
,:ID: 100
,:END:
,- this is just a test

File 2:

* heading 1
** test heading
,:PROPERTIES:
,:ID: 100
,:END:
,- updated line in file 2
* heading 2
,- new text under heading 2
,- this will conflict since heading 2
,  deleted in file 1
** test heading
,- this is a different heading
,- this line added in file 2
----------------
Node Change List:
----------------
Remove nodes: file 0
(:title "heading 2" :level 1 :parent-level 0 :id "" :text "")
----------
Add nodes: file 1
(:title "heading 3" :level 1 :parent-level 0 :id "" :text "")
(:title "heading 4" :level 2 :parent-level 1 :id "" :text "")
----------
Remove nodes: file 0
----------
Add nodes: file 2
----------------------
FILE : 0 NO_CHANGE
(:title "" :level 0 :no-parent :id "" :text "")
FILE : 2 REMOVE
(:title "heading 2" :level 1 :parent-level 0 :id "" :text "")
FILE : 1 NEW
(:title "heading 3" :level 1 :parent-level 0 :id "" :text "")
FILE : 1 NEW
(:title "heading 4" :level 2 :parent-level 1 :id "" :text "")
FILE : 1 MOVE
(:title "test heading" :level 3 :parent-level 2 :id "100" :text ":PROPERTIES:
:ID: 100
:END:
- this is just a test
")
FILE : 1 NO_CHANGE
(:title "heading 1" :level 1 :parent-level 0 :id "" :text "")
FILE : 1 MOVE
(:title "test heading" :level 2 :parent-level 1 :id "" :text "- this is a different heading
")

Merged Document:

,<<<<<<< yours: t1-1.org
,=======
* heading 2
,- new text under heading 2
,- this will conflict since heading 2
,  deleted in file 1
,>>>>>>> theirs: t1-2.org
* heading 3
** heading 4
** test heading
,:PROPERTIES:
,:ID: 100
,:END:
,- updated line in file 2
* heading 1
** test heading
,- this is a different heading
,- this line added in file 2

In this example, the ID was used to distinguish the headings called 'test heading', and a heading could be moved in one document and content updated in another without a conflict. An identical content change in two files would not have resulted in a conflict. If a identical heading is added to each of the documents, then the merged result will have two identical headings without conflict.

Documentation from the http://orgmode.org/worg/ website (either in its HTML format or in its Org format) is licensed under the GNU Free Documentation License version 1.3 or later. The code examples and css stylesheets are licensed under the GNU General Public License v3 or later.