Org agenda filter by headline depth

Question

Let's say I have a custom TODO tag called 'NEXT' and a file gtd.org which contains the following:

* Some category
** TODO Big project in category
*** NEXT Big step to completing project
**** NEXT Small step to completing big step

In my custom agenda view, I have a block listing everything with a NEXT tag. The problem is that this block lists the big step and the small step, whereas I only want to see the small step. That is, I'm looking for one of the following solutions, from most desirable to least desirable:

• Do not show a 'NEXT' headline if it has a child with 'NEXT' (probably resource heavy)
• Sort the agenda block so that greater headline depth is on top
• Have different blocks for different headline depths

I know that org can detect headline depth, because when setting org-agenda-prefix-format its possible to add a number of spaces spaces to the prefix equaling the headline depth (using %l).

Any ideas?

Answer 1

Having studied org-mode for a few weeks, I believe I can answer my own question.

• To hide headlines with children in TODO states, first put this in your init.el or equivalent:

  (setq org-enforce-todo-dependencies t)
  

  The above will prevent a headline from entering a DONE state while a child is in a TODO state. TODO headlines with at least one child in a TODO state have the property BLOCKED. To prevent BLOCKED headlines from showing in agenda views, use

  (setq org-agenda-dim-blocked-tasks 'invisible)
  

• Sorting the agenda block by headline depth is possible by creating a custom sorting strategy. The depth of a headline is given by the property LEVEL. As an example where LEVEL is used, org defaults to determining stuck projects by first tag searching for "+LEVEL=2/-DONE". For more information, look up the syntax of tag searching.

• Distinct blocks for distinct headline depths can be achieved by using the LEVEL property, as described above.