path: root/lisp/nxml/TODO

* High priority

** Command to insert an element template, including all required
attributes and child elements.  When there's a choice of elements
possible, we could insert a comment, and put an overlay on that
comment that makes it behave like a button with a pop-up menu to
select the appropriate choice.

** Command to tag a region.  With a schema should complete using legal
tags, but should work without a schema as well.

** Provide a way to conveniently rename an element. With a schema should
complete using legal tags, but should work without a schema as well.

* Outlining

** Implement C-c C-o C-q.

** Install pre/post command hook for moving out of invisible section.

** Put a modify hook on invisible sections that expands them.

** Integrate dumb folding somehow.

** An element should be able to be its own heading.

** Optimize to avoid complete buffer scan on each command.

** Make it work with HTML-style headings (i.e. level indicated by
name of heading element rather than depth of section nesting).

** Recognize root element as a section provided it has a title, even
if it doesn't match section-element-name-regex.

** Support for incremental search automatically making hidden text
visible.

** Allow title to be an attribute.

** Command that says to recognize the tag at point as a section/heading.

** Explore better ways to determine when an element is a section
or a heading.

** rng-next-error needs to either ignore invisible portion or reveal it
(maybe use isearch oriented text properties).

** Errors within hidden section should be highlighted by underlining the
ellipsis.

** Make indirect buffers work.

** How should nxml-refresh outline recover from non well-formed tags?

** Hide tags in title elements?

** Use overlays instead of text properties for holding outline state?
Necessary for indirect buffers to work?

** Allow an outline to go in the speedbar.

** Split up outlining manual section into subsections.

** More detail in the manual about each outlining command.

** More menu entries for hiding/showing?

** Indication of many lines have been hidden?

* Locating schemas

** Should rng-validate-mode give the user an opportunity to specify a
schema if there is currently none? Or should it at least give a hint
to the user how to specify a non-vacuous schema?

** Support for adding new schemas to schema-locating files. Add
documentElement and namespace elements.

** C-c C-w should be able to report current type id.

** Implement doctypePublicId.

** Implement typeIdBase.

** Implement typeIdProcessingInstruction.

** Support xml:base.

** Implement group.

** Find preferred prefix from schema-locating files.  Get rid of
rng-preferred-prefix-alist.

** Inserting document element with vacuous schema should complete using
document elements declared in schema locating files, and set schema
appropriately.

** Add a ruleType attribute to the <include> element?

** Allow processing instruction in prolog to contain the compact syntax
schema directly.

** Use RDDL to locate a schema based on the namespace URI.

** Should not prompt to add redundant association to schema locating
file.

** Command to reload current schema.

* Schema-sensitive features

** Should filter dynamic markup possibilities using schema validity, by
adding hook to nxml-mode.

** Dynamic markup word should (at least optionally) be able to look in
other buffers that are using nxml-mode.

** Should clicking on Invalid move to next error if already on an error?

** Take advantage of a:documentation. Needs change to schema format.

** Provide feasible validation (as in Jing) toggle.

** Save the validation state as a property on the error overlay to enable
more detailed diagnosis.

** Provide an Error Summary buffer showing all the validation errors.

** Pop-up menu.  What is useful?  Tag a region (should be greyed out if
the region is not balanced).  Suggestions based on error messages.

** Have configurable list of namespace URIs so that we can provide
namespace URI completion on extension elements or with schema-less
documents.

** Allow validation to handle XInclude.

** ID/IDREF support.

* Completion

** Make it work with icomplete.  Only use a function to complete when
some of the possible names have undeclared namespaces.

** How should C-return in mixed text work?

** When there's a vacuous schema, C-return after < will insert the
end-tag.  Is this a bug or a feature?

** After completing start-tag, ensure we don't get unhelpful message
from validation

** Syntax table for completion.

** Should complete start-tag name with a space if namespace attributes
are required.

** When completing start-tag name with no prefix and it doesn't match
should try to infer namespace from local name.

** Should completion pay attention to characters after point?  If so,
how?

** When completing start-tag name, add required atts if only one required
attribute.

** When completing attribute name, add attribute value if only one value
is possible.

** After attribute-value completion, insert space after close delimiter
if more attributes are required.

** Complete on enumerated data values in elements.

** When in context that allows only elements, should get tag
completion without having to type < first.

** When immediately after start-tag name, and name is valid and not
prefix of any other name, should C-return complete on attribute names?

** When completing attributes, more consistent to ignore all attributes
after point.

** Inserting attribute value completions needs to be sensitive to what
delimiter is used so that it quotes the correct character.

** Complete on encoding-names in XML decl.

** Complete namespace declarations by searching for all namespaces
mentioned in the schema.

* Well-formed XML support

** Deal better with Mule-UCS

** Deal with UTF-8 BOM when reading.

** Complete entity names.

** Provide some support for entity names for MathML.

** Command to repeat the last tag.

** Support for changing between character references and characters.
Need to check that context is one in which character references are
allowed.  xmltok prolog parsing will need to distinguish parameter
literals from other kinds of literal.

** Provide a comment command to bind to M-; that works better than the
normal one.

** Make indenting in a multi-line comment work.

** Structure view.  Separate buffer displaying element tree. Be able to
navigate from structure view to document and vice-versa.

** Flash matching >.

** Smart selection command that selects increasingly large syntactically
coherent chunks of XML.  If point is in an attribute value, first
select complete value; then if command is repeated, select value plus
delimiters, then select attribute name as well, then complete
start-tag, then complete element, then enclosing element, etc.

** ispell integration.

** Block-level items in mixed content should be indented, e.g:
  <para>This is list:
    <ul>
      <li>item</li>

** Provide option to indent like this:

**   <para>This is a paragraph
    occupying multiple lines.</para>

** Option to add make a / that closes a start-tag electrically insert a
space for the XHTML guys.

** C-M-q should work.

* Datatypes

** Figure out workaround for CJK characters with regexps.

** Does category C contain Cn?

** Do ENTITY datatype properly.

* XML Parsing Library

** Parameter entity parsing option, nil (never), t (always),
unless-standalone (unless standalone="yes" in XML declaration).

** When a file is currently being edited, there should be an option to
use its buffer instead of the on-disk copy.

* Handling all XML features

** Provide better support for editing external general parsed entities.
Perhaps provide a way to force ignoring undefined entities; maybe turn
this on automatically with <?xml encoding=""?> (with no version
pseudo-att).

** Handle internal general entity declarations containing elements.

** Handle external general entity declarations.

** Handle default attribute declarations in internal subset.

** Handle parameter entities (including DTD).

* RELAX NG

** Do complete schema checking, at least optionally.

** Detect include/external loops during schema parse.

** Coding system detection for schemas.  Should use utf-8/utf-16 per the
spec. But also need to allow encodings other than UTF-8/16 to support
CJK charsets that Emacs cannot represent in Unicode.

* Catching XML errors

** Check public identifiers.

** Check default attribute values.

* Performance

** Explore whether overlay-recenter can cure overlays performance
problems.

** Cache schemas. Need to have list of files and mtimes.

** Make it possible to reduce rng-validate-chunk-size significantly,
perhaps to 500 bytes, without bad performance impact: don't do
redisplay on every chunk; pass continue functions on other uses of
rng-do-some-validation.

** Cache after first tag.

** Introduce a new name class that is a choice between names (so that
we can use member)

** intern-choice should simplify after patterns with same 1st/2nd args

** Large numbers of overlays slow things down dramatically.  Represent
errors using text properties.  This implies we cannot incrementally
keep track of the number of errors, in order to determine validity.
Instead, when validation completes, scan for any characters with an
error text property; this seems to be fast enough even with large
buffers. Problem with error at end of buffer, where there's no
character; need special variable for this.  Need to merge face from
font-lock with the error face: use :inherit attribute with list of two
faces.  How do we avoid making rng-valid depend on nxml-mode?

* Error recovery

** Don't stop at newline in looking for close of start-tag.

** Use indentation to guide recovery from mismatched end-tags

** Don't keep parsing when currently not well-formed but previously
well-formed

** Try to recover from a bad start-tag by popping an open element if
there was a mismatched end-tag unaccounted for.

** Try to recover from a bad start-tag open on the hypothesis that there
was an error in the namespace URI.

** Better recovery from ill-formed XML declarations.

* Useability improvements

** Should print a "Parsing..." message during long movements.

** Provide better position for reference to undefined pattern error.

** Put Well-formed in the mode-line when validating against any-content.

** Trim marking of illegal data for leading and trailing whitespace.

** Show Invalid status as soon as we are sure it's invalid, rather than
waiting for everything to be completely up to date.

** When narrowed, Valid or Invalid status should probably consider only
validity of narrowed region.

* Bug fixes

** Need to give an error for a document like: <foo/><![CDATA[  ]]>

** Make nxml-forward-balanced-item work better for the prolog.

** Make filling and indenting comments work in the prolog.

** Should delete RNC Input buffers.

** Figure out what regex use for NCName and use it consistently,

** Should have not-well-formed tokens in ref.

** Require version in XML declaration? Probably not because prevents
use for external parsed entities. At least forbid standalone
without version.

** Reject schema that compiles to rng-not-allowed-ipattern.

** Move point backwards on schema parse error so that it's on the right token.

* Internal

** Use rng-quote-string consistently.

** Use parsing library for XML to texinfo conversion.

** Rename xmltok.el to nxml-token.el.  Use nxml-t- prefix instead of
xmltok-. Change nxml-t-type to nxml-t-token-type, nxml-t-start to
nxml-t-token-start.

** Can we set fill-prefix to nil and rely on indenting?

** xmltok should make available replacement text of entities containing
elements

** In rng-valid, instead of using modification-hooks and
insert-behind-hooks on dependent overlays, use same technique as
nxml-mode.

** Port to XEmacs.  Issues include: Unicode (XEmacs seems to be based on
Mule-UCS); overlays/text properties vs extents; absence of
fontification-functions hook.

* Fontification

** Allow face to depend on element qname, attribute qname, attribute
value.  Use list with pairs of (R . F), where R specifies regexps and
F specifies faces.  How can this list be made to depend on the
document type?

* Other

** Support RELAX NG XML syntax (use XML parsing library).

** Support W3C XML Schema (use XML parsing library).

** Command to infer schema from current document (like trang).

* Schemas

** XSLT schema should take advantage of RELAX NG to express cooccurrence
constraints on attributes (e.g. xsl:template).

* Documentation

** Move material from README to manual.

** Document encodings.

* Notes

** How can we allow an error to be displayed on a different token from
where it is detected?  In particular, for a missing closing ">" we
will need to display it at the beginning of the following token.  At
the moment, when we parse the following token the error overlay will
get cleared.

** How should rng-goto-next-error deal with narrowing?

** Perhaps should merge errors having same start position even if they
have different ends.

** How to handle surrogates? One possibility is to be compatible with
utf8.e: represent as sequence of 4 chars.  But utf-16 is incompatible
with this.

** Should we distinguish well-formedness errors from invalidity errors?
(I think not: we may want to recover from a bad start-tag by implying
an end-tag.)

** Seems to be a bug with Emacs, where a mouse movement that causes
help-echo text to appear counts as pending input but does not cause
idle timer to be restarted.

** Use XML to represent this file.

** I had a TODO which said simply "split-string". What did I mean?

** Investigate performance on large files all on one line.

* Issues for Emacs versions >= 22

** Take advantage of UTF-8 CJK support.

** Supply a next-error-function.

** Investigate this NEWS item "Emacs now tries to set up buffer coding
systems for HTML/XML files automatically."

** Take advantage of the pointer text property.

** Leverage char-displayable-p.

Local variables:
mode: outline
end: