Node:Commands for locating a schema, Next:Schema locating files, Up:Locating a schema
The command C-c C-w will tell you what schema is currently being used.
The rules for locating a schema are applied automatically when
you visit a file in nXML mode. However, if you have just created a new
file and the schema cannot be inferred from the file-name, then this
will not locate the right schema. In this case, you should insert the
start-tag of the root element and then use the command C-c
C-a, which reapplies the rules based on the current content of
the document. It is usually not necessary to insert the complete
start-tag; often just <name is
enough.
If you want to use a schema that has not yet been added to the
schema locating files, you can use the command C-c C-s to
manually select the schema for the document in current buffer. Emacs
will read the file-name of the schema from the minibuffer. After
reading the file-name, Emacs will ask whether you wish to add a rule
to a schema locating file that persistently associates the document
with the selected schema. The rule will be added to the first file in
the list specified rng-schema-locating-files; it will
create the file if necessary, but will not create a directory. If the
variable rng-schema-locating-files has not been
customized, this means that the rule will be added to the file
schemas.xml in the same directory as the document being
edited.
The command C-c C-t allows you to select a schema by specifying an identifier for the type of the document. The schema locating files determine the available type identifiers and what schema is used for each type identifier. This is useful when it is impossible to infer the right schema from either the file-name or the content of the document, even though the schema is already in the schema locating file. A situation in which this can occur is when there are multiple variants of a schema where all valid documents have the same document element. For example, XHTML has Strict and Transitional variants. In a situation like this, a schema locating file can define a type identifier for each variant. As with C-c C-s, Emacs will ask whether you wish to add a rule to a schema locating file that persistently associates the document with the specified type identifier.
The command C-c C-l adds a rule to a schema locating file that persistently associates the document with the schema that is currently being used.