#+title:Orgmunge
* Motivation and scope
Orgmunge was born out of the desire to modify Org documents
programmatically from within Python. The wonderful [[https://github.com/karlicoss/orgparse][orgparse]] can read
an Org document into a tree object but doesn't offer an interface to
modify the tree and write it back to file.

The original use case was trying to sync Outlook calendar items with
Org: whenever someone rescheduled a meeting, my Python script was
unable to reschedule the Org heading it had originally
created. Instead of forking =orgparse=, I decided to write an actual
grammar for an Org document and use [[https://github.com/dabeaz/ply][PLY]] to generate a parser for it.

Now Org syntax is too sophisticated for me to claim that this first
attempt can parse everything. In fact, some folks way smarter than I
am (and with more formal training), have hinted that Org
syntax can't be properly parsed with a context-free grammar. For such
reasons (and for my own lack of experience with writing grammars), I
have restricted the scope of this module to the features I care about:
for each heading, the headline components (the =COMMENT= keyword, the
todo state, priority, cookies, and tags) are all parsed, as well as
any scheduling timestamps and all the drawers. The heading contents
are treated as a blob of text and the only thing the parser extracts
from the contents are the timestamps. No attempts are made at parsing
things like tables or source code blocks further. =orgmunge= can also
parse out the document's metadata and export options but the major
assumption it makes is that the document starts out with some optional
metadata and export options, followed by some optional initial body
text (not falling under any heading), and then a tree of headings. Any
export options or metadata that come later within the document are
treated as text (some heading's content).

* Installation
- The only dependency of =orgmunge= is =PLY=. So you need =PLY= installed.
- Clone this repo
- Add the directory where you cloned this repo to your =PYTHONPATH=
- The parser recognizes todo keywords by looking for a file named
  =todos.json= in one of 3 places:
  1. The current directory
  2. The user's home directory
  3. The package directory
- You can look at the file =todos.json= shipped with this package for
  the expected syntax and customize it with your preferred todo
  keywords (or make a copy in your home directory). =orgmunge= doesn't
  currently support reading todo states defined with =#+TODO= in the
  file it's reading, and there are no plans to do so in the near
  future (see [[https://github.com/durableOne/orgmunge/issues/3][this issue]]).
- Here's an example:
  #+begin_src javascript
    {
        "todo_states":
        {
            "my_todo": "TODO",
            "my_next": "NEXT",
            "my_wait": "WAIT"
        },
        "done_states":
        {
            "my_cncl": "CNCL",
            "my_done": "DONE"
        }
    }
  #+end_src
  The dict keys can be any names meaningful to you and will be exposed
  as keys to the =_todo_keywords=, =_todo_states=, and =_done_states= attributes
  of the =Headline= class. The dict values are the actual todo keywords
  that will be in the Org file you're reading.

  The file in the repo has a different example with Font Awesome
  characters as the todo keywords.
* Usage
** Reading an Org tree

- The =Org= class in =__init__.py= is the main entry point to =orgmunge=.
  It can be used to read an Org tree either from a string or from a
  file:
  #+begin_src python
    from orgmunge import Org

    org_1 = Org('* TODO Something important\n', from_file=False) # \n needed to signify end of document
    org_2 = Org('/path/to/my/file.org')
    org_3 = Org('/path/to/my/file.org', debug=True) # Print PLY debugging info
  #+end_src
- The =Org= object has 3 main attributes you should care about:
  1. =Org.metadata= stores the metadata and export options found at the
     beginning of the file. This is a dict mapping the option/keyword
     name to a list of its values (to allow for cumulative keywords
     such as =#+OPTION=). Example:
     #+begin_src python
       org_1 = Org('#+title: Test\n') 
       assert(org_1.metadata['title'] == ['Test'])
     #+end_src
  2. =Org.initial_body= stores any text between the metadata and the
     first heading.
  3. =Org.root= stores the root of the Org tree. This is a [[*Heading Objects][heading]] with
     the [[*Headline Objects][headline]] =ROOT= whose only useful attribute is =children=, which is a
     list of all the [[*Heading Objects][headings]] in the given document.
- The Org tree is a list of [[file:__init__.py::def _classify_headings(self, lst):][headings]] with parent, child and sibling relationships.

  
*** Heading Objects
- A heading object consists of:
  1. A [[*Headline Objects][headline]] 
  2. Contents:
     1) [[*Scheduling Objects][Scheduling]], if any
     2) A list of [[*Drawer Objects][Drawers]], if any
     3) Body text, if any
- Important attributes:
  1. =properties=. This is a dict mapping property names to their
     values. The properties are parsed from the =PROPERTIES= drawer if
     it exists. This attribute can also be set by the user (the value
     supplied must be a dict).
  2. =headline= returns the heading's headline. This attribute can also
     be set by a user (the value must be a [[*Headline Objects][Headline]] instance).
  3. =scheduling= is a [[*Scheduling Objects][Scheduling]] object containing information about
     =SCHEDULED/DEADLINE/CLOSED= timestamps of the heading, if any. Can
     also be set by the user (the value must be a Scheduling instance).
  4. =drawers= is a list of [[*Drawer Objects][Drawer]] objects containing the drawers
     associated with this heading. When you update the heading's
     =properties= attribute, the =PROPERTIES= drawer is updated the next
     time you access it.
  5. =children= returns a list of Heading objects that are the direct
     children of this heading.
  6. =parent= returns the parent heading of the current one. If the
     current heading is a top-level heading, the root heading will be
     returned.
  7. =sibling= returns the sibling heading of the current one that comes
     before it in the tree, if any. The reason this is the sibling
     heading that is formally tracked is because it's the one that
     would adopt the current heading whenever the current heading is
     demoted. If you want a list of all siblings of the current
     heading, you can do this:
     #+begin_src python
       siblings = [c for c in current_heading.parent.children if c is not current_heading]
     #+end_src
  8. =level= is the heading's level, with 1 being the top level and each
     sub-level after that being incremented by 1 (the heading's level
     is the number of "stars" before its headline).
- Important methods:
  1. =clocking=. This returns a list of [[*Clocking Objects][Clocking]] objects, parsed
     from the heading's =LOGBOOK= drawer, if any. You can also pass the
     optional boolean parameter =include_children=, which, when True,
     includes clocking information of this heading's children as well.
  2. =add_child= accepts a Heading object to add as a child to the
     current heading. The optional boolean parameter =new= should be set
     to =True= when this is a new heading that was created and needs to
     be assigned a parent. It should be set to =False= (default) when
     the addition of a child is due to a promotion/demotion operation.
  3. =remove_child= accepts a heading object and deletes it from the
     current heading's children if it's a child of the current
     heading.
  4. =promote= promotes the current heading one level. If the heading has
     children, they would be orphaned so this raises a
     =ValueError=. Technically, Org allows you to have, say, level 3
     headings under a level 1 heading, but =orgmunge= does not allow
     this to make parsing the tree easier.
  5. =promote_tree= promotes the current heading and all its
     descendants. Use this if the heading you want to promote has
     children.
  6. =demote= demotes the current heading one level. If the current
     heading has no sibling to adopt it, the demotion attempt fails
     and raises a =ValueError=.
  7. =demote_tree= is the equivalent of =promote_tree= for demotion.
*** Headline Objects
- Important attributes:
  1. =done= is a boolean attribute that determines whether the headline
     is in one of the done states. You can't set this attribute directly.
  2. =level= is the headline's level (the number of "stars" before the
     title)
  3. =comment= is a boolean attribute that determines whether a headline
     is commented out (by having the keyword =COMMENT= inserted before
     the title).
  4. =todo= returns/sets the headline's todo state. You can set it
     yourself but it has to be one of the values of =self._todo_states=
     or =self._done_states=.
  5. =cookie= returns/sets the headline's cookie. See [[*Cookie Objects][Cookie Objects]].
  6. =priority= returns/sets the headline's priority
- Important methods:
  1. =promote= decreases the level by the number given by the parameter
     =n= (default 1).
  2. =demote= acts like =promote= but increases the level by =n= instead.
  3. =toggle_comment= toggles the state of whether or not a headline is
     commented out using the =COMMENT= keyword.
     1. =comment_out= ensures the headline is commented out using
        =COMMENT=
     2. =uncomment= ensures the headline is not commented out using the
        =COMMENT= keyword.
     3. =raise_priority= increases the headline's priority by 1
     4. =lower_priority= decreases the headline's priority by 1
*** Scheduling Objects
- Has 6 attributes for the 3 possible scheduling keywords (3 are aliases of the other 3):
  1. CLOSED, closed
  2. SCHEDULED, scheduled
  3. DEADLINE, deadline
- Each attribute, when queried will return either =None= or a =TimeStamp=
  object representing the timestamp associated with this particular
  scheduling keyword. You can set the attributes directly but they
  have to be set to a =TimeStamp= object. 
*** Drawer Objects
- A =Drawer= object has only 2 attributes: =name= and =contents=. The
  =contents= attribute is simply a list of lines making up the drawer
  contents. When you modify a heading's =properties= attribute, its
  =PROPERTIES= drawer gets updated accordingly.
*** Clocking Objects
- The =Clocking= objects have 3 attributes: =start_time=, =end_time= and
  =duration=. Only the first 2 can be set. When setting either, you
  should pass a string following the Org time format; namely,
  '%Y-%m-%d %a %H:%M' (see the [[https://man7.org/linux/man-pages/man3/strftime.3.html][strftime(3)]] man page for an explanation
  of the format codes).
- If =end_time= is =None=, the duration is calculated from the =start_time=
  up to the current moment.
*** Priority Objects
- The only attribute, =priority= can be set directly by the user and can
  be one of only 3 strings: 'A', 'B' or 'C'. Set to =None= to remove it
  from the =Heading=.
- The methods =_raise= and =_lower= will raise or lower the priority.
- If the priority is =None=, raising it, sets it to 'A' and lowering it
  sets it to 'C'.
*** TimeStamp Objects
- Important attributes:
  1. =start_time= and =end_time= can be queried and set by the user. You
     can set them by supplying a string, a =datetime= object or =None=.
  2. =repeater= returns a timestamp repeater string such as '+1w'. Can
     also be set by the user.
  3. =deadline_warn= acts similarly to =repeater= and represents the
     number of days before a deadline to warn the user of an upcoming
     deadline.
  4. =active= is a boolean property and decides whether the time stamp
     will be printed with =[]= or =<>= delimiters. Can be set directly by
     the user.
*** Cookie Objects
- =Cookie= objects represent progress on the current =Heading=.
- They can be of type 'percent' (e.g. [50%]) or of type 'progress' (e.g. [2/4]).
  
- Important attributes:
  1. =cookie_type=: can only be one of 'percent' or 'progress'. Can be
     set directly by the user.
  2. =m= and =n= represent the progress as the ratio =m/n=. If the cookie
     type is 'percent', =n= is 100. When changing =cookie_type=, =m= and =n=
     are converted accordingly.
** Modifying an Org tree
- The ability to modify the tree was the main reason I wrote this
  package. Most of the attributes of the tree objects can be modified
  directly by the user.
- Use the =promote*= and =demote*= methods of the =Heading= objects to
  change =Heading= levels.
- To rearrange headings, note that a =Heading's= =children=
  attribute is a list whose ordering is important: in other words, the
  tree will be written back to a file with the order each =Heading='s
  children are in. So the user can rearrange the headings of the same level
  by assigning the =children= attribute of their parent to a different
  order of child headings. It's up to the user to update the child
  headings' =sibling= attributes appropriately.
** Writing an Org tree
- You can use the =Org= object's =write= method to write out the tree to a
  file whose name you supply to the method:
  #+begin_src python
    from orgmunge import Org

    agenda = Org('/path/to/agenda.org')

    # Do something with agenda...

    agenda.write('/path/to/modified_agenda.org')
  #+end_src
  
* License
#+INCLUDE: ./LICENSE



* Contributors
:PROPERTIES:
:ID:       d27f8cd9-4be9-4fa3-b54a-40b9d3807e90
:END:
:LOGBOOK:
CLOCK: [2023-07-08 Sat 15:54]--[2023-07-08 Sat 15:54] =>  0:00
:END:
Thanks to these wonderful people for contributing time and code:

- [[https://github.com/Nalisarc][Nalisarc]]
