| Author: | David Goodger |
|---|---|
| Contact: | docutils-develop@lists.sourceforge.net |
| Revision: | 9051 |
| Date: | 2022-04-02 |
| Copyright: | This document has been placed in the public domain. |
Contents
Transforms change the document tree in-place, add to the tree, or prune it. Transforms resolve references and footnote numbers, process interpreted text, and do other context-sensitive processing. Each transform is a subclass of docutils.transforms.Transform.
There are transforms added by components, others (e.g. parts.Contents) are added by the parser, if a corresponding directive is found in the document.
To add a transform, components (objects inheriting from Docutils.Component like Readers, Parsers, Writers, Input, Output) overwrite the get_transforms() method of their base class. After the Reader has finished processing, the Publisher calls Transformer.populate_from_components() with a list of components and all transforms returned by the component's get_transforms() method are stored in a transformer object attached to the document tree.
For more about transforms and the Transformer object, see also PEP 258. (The default_transforms() attribute of component classes mentioned there is deprecated. Use the get_transforms() method instead.)
Transform classes each have a default_priority attribute which is used by the Transformer to apply transforms in order (low to high). The default priority can be overridden when adding transforms to the Transformer object.
| Transform: module.Class | Added By | Priority |
|---|---|---|
| misc.class | "class" (d/p) | 210 |
| references.Substitutions | standalone (r), pep (r) | 220 |
| references.PropagateTargets | standalone (r), pep (r) | 260 |
| frontmatter.DocTitle | standalone (r) | 320 |
| frontmatter.DocInfo | standalone (r) | 340 |
| frontmatter.SectSubTitle | standalone (r) | 350 |
| peps.Headers | pep (r) | 360 |
| peps.Contents | pep (r) | 380 |
| universal.StripClasses... | Writer (w) | 420 |
| references.AnonymousHyperlinks | standalone (r), pep (r) | 440 |
| references.IndirectHyperlinks | standalone (r), pep (r) | 460 |
| peps.TargetNotes | pep (r) | 520 |
| references.TargetNotes | peps.TargetNotes (t/p) | 0 |
| misc.CallBack | peps.TargetNotes (t/p) | 1 |
| references.TargetNotes | "target-notes" (d/p) | 540 |
| references.Footnotes | standalone (r), pep (r) | 620 |
| references.ExternalTargets | standalone (r), pep (r) | 640 |
| references.InternalTargets | standalone (r), pep (r) | 660 |
| parts.SectNum | "sectnum" (d/p) | 710 |
| parts.Contents | "contents" (d/p), peps.Contents (t/p) | 720 |
| universal.StripComments | Reader (r) | 740 |
| peps.PEPZero | peps.Headers (t/p) | 760 |
| components.Filter | not used | 780 |
| universal.Decorations | Reader (r) | 820 |
| misc.Transitions | standalone (r), pep (r) | 830 |
| universal.ExposeInternals | Reader (r) | 840 |
| references.DanglingReferences | standalone (r), pep (r) | 850 |
| universal.SmartQuotes | Parser | 855 |
| universal.Messages | Writer (w) | 860 |
| universal.FilterMessages | Writer (w) | 870 |
| universal.TestMessages | DocutilsTestSupport | 880 |
| writer_aux.Compound | not used, to be removed | 910 |
| writer_aux.Admonitions | html4css1 (w), latex2e (w) | 920 |
| misc.CallBack | n/a | 990 |
Key:
| Priority | ||
|---|---|---|
| From | To | Category |
| 0 | 99 | immediate execution (added by another transform) |
| 100 | 199 | very early (non-standard) |
| 200 | 299 | very early |
| 300 | 399 | early |
| 400 | 699 | main |
| 700 | 799 | late |
| 800 | 899 | very late |
| 900 | 999 | very late (non-standard) |