Make XSD validation namespace-aware and enforce the form defaults and
xs:all structural constraints that were previously ignored:
- targetNamespace is tracked: a schema's global elements are in its
target namespace, and an instance's root element must be in it.
- elementFormDefault / attributeFormDefault (and per-declaration form)
qualify local element and attribute declarations. The content-model
matcher already compares namespace URIs, so qualified declarations
now match only same-namespace instance nodes; attribute matching
became namespace-aware too.
- xs:all groups are checked at compile time: every member must be an
element occurring at most once, the group may occur at most once, and
nested model groups inside an all are rejected (a SchemaError).
When a schema has no target namespace the stamping is a no-op, so
unqualified schemas validate exactly as before.
Cross-namespace type references through xs:import resolve by local name
only; full multi-namespace type tables are not modeled.
Closes#78
Read and enforce the XSD 1.0 derivation controls that were previously
ignored:
- abstract elements may not appear in an instance directly, only through
a substitution member; an element of an abstract complex type must
supply an xsi:type naming a concrete derived type.
- block on a type forbids the disallowed xsi:type substitutions; block on
an element drops substitution-group members that derive by a blocked
method.
- final on a type rejects, at compile time, any type that derives from it
by a final method.
- xs:redefine requires the redefined type to derive from itself.
Track each named complex type's base and derivation method as the
backbone these checks walk. Also compose complexContent extension and
restriction content models, which were previously dropped: an extension
now inherits its base's attributes and content (base first, then the
extension, in sequence).
Complex-type restriction is not verified to be a structurally valid
subset of its base (Particle Valid (Restriction)); that limit is
documented at its sites.
Closes#76
Add xs:any and xs:anyAttribute wildcards with namespace and
processContents constraints (skip/lax/strict), and resolve the
list built-in datatypes (IDREFS, ENTITIES, NMTOKENS) to their
item types so each list item validates.
WildcardNamespace models ##any/##other/enumerated URI sets;
Wildcard.admits gates undeclared attributes and wildcard-matched
children. ContentNFA.follow exposes the follow set for completions.
Closes#77
Closes#75, on the validation framework. XSD instance-level features:
- nillable elements: an xsi:nil="true" element is accepted (its content model is
not checked) only when the element is declared nillable and carries no content;
xsi:nil on a non-nillable element, or a nilled element with content, is a
located error.
- fixed value constraints: a present fixed attribute must equal its fixed value,
and a fixed element's text must match.
- default/fixed are parsed onto AttributeUse (per use) and collected per element
name (nillable set + value constraints), threaded through XSDContext to the
ComplexValidator.
All findings are located ValidationErrors. Collection and helper methods move to
same-file extensions to stay within type-body limits.
Validate XSD identity constraints over the instance document in a pass that
walks the tree alongside type validation:
- xs:unique requires the selected nodes' field tuples to be distinct, excluding
any node that is missing a field.
- xs:key additionally requires every field to be present.
- xs:keyref requires each tuple to equal a tuple of the named key or unique
visible in an enclosing scope, resolved through a stack of scope frames so a
keyref and the key it refers to may sit on the same element.
The selector and field XPaths run on the existing XPath engine, relative to the
declaring element and each selected node. Constraints are gathered for every
element declaration at any depth, keyed by element name.
Closes#67
Compose schemas across documents and resolve types at the instance:
- xs:include, xs:import, and xs:redefine pull a transitive closure of schema
documents through an injected loader (resolved by schemaLocation), base
schemas first so the including schema wins; a redefine's nested definitions
override the schema it includes.
- substitution groups: an xs:element ref to a head also admits every element
that substitutes for it, expanded at parse time into a choice over the head
and its transitive members.
- xsi:type overrides an element's declared type with the named type at the
instance; XML Schema instance attributes are exempt from attribute checks.
The schema parser splits across XSDContext (shared tree helpers, document
collection, parsing context), XSDSimpleParser (simple types and facets), and
XSDParser (elements, complex types, model groups) to keep each within bounds.
Closes#66
