2.1 KiB
Document model
Source ranges
The lexical scan records exact half-open offsets for each opening/full element, name and quoted attribute. CodeMirror's Lezer XML parser supplies ranged syntax errors; a separate stack scan rejects structures browser DOM parsers might repair. The DOM parse supplies namespace and decoded semantic values. Element order must match the lexical tokens or parsing fails with a source-map mismatch.
DOCTYPE text remains in canonical source but is removed before DOM parsing. Entity declarations are rejected for the semantic model. External entities are never resolved.
Stable keys
A unique explicit SVG id becomes id:<id>. Otherwise a key hashes structural
path, source offset, local name and optional ID; collision suffixes are
in-memory. Reparsing retains explicit-ID identity and best-effort structural
identity. Keys appear only as temporary data-svg-tools-node attributes in the
editing projection and are stripped from exports.
Semantic nodes
Nodes retain namespace/name, parent and children, depth, ID/classes, decoded attributes, exact attribute ranges, render status and leaf text. The document also records indentation/newline/quote preference, ordered keys, diagnostics and bounded metrics.
Unknown well-formed source remains canonical even when there is no inspector. A targeted command patches only its attribute/tag range. Whole-source serialization occurs only for explicit format, sanitize or optimize workflows, each with a source diff.
Invalid state
Every source update gets a monotonically increasing revision. If current source is invalid, diagnostics refer to that text while the canvas/tree use the last valid snapshot and all visual controls are disabled. Once the same current revision parses and sanitizes successfully it atomically replaces the snapshot.
Resource limits can make otherwise well-formed source invalid for this app. Limits cover bytes, structure, path/CSS/reference/animation/filter counts, embedded data and total text. This prevents unbounded model construction but is not a promise that every file below a limit is inexpensive on every device.