Documentation
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Overview ¶
Package svg converts SVG documents to TDTP packets and back.
Data model: each SVG element (and each text node inside mixed-content parents) becomes one row. Tree structure is encoded via parent_id + materialized path (zero-padded "/001/002") and per-parent order_idx.
Round-trip is lossy by design: byte-identical output is NOT a goal (attribute order, whitespace, namespace prefix choices may differ). Visual/DOM-level fidelity IS the goal. See pkg/svg/svg_test.go for round-trip coverage.
Index ¶
Constants ¶
const TableName = "svg_elements"
TableName is the TDTP table name used for SVG packets. Constant so that --from-svg / --to-svg / --inspect all agree on the name.
const TagTextNode = "_text_node"
TagTextNode is the framework-internal tag used for mixed-content text nodes (e.g. "Hello " in <text>Hello <tspan>world</tspan>!</text>). The leading underscore makes it visually distinct from any real SVG element name and unlikely to collide with namespaced elements.
Variables ¶
var SVGDictionary = []packet.DictEntry{
{Short: "@W3", Full: "http://www.w3.org/2000/svg"},
{Short: "@xlink", Full: "http://www.w3.org/1999/xlink"},
{Short: "@inks", Full: "http://www.inkscape.org/namespaces/inkscape"},
{Short: "@sodi", Full: "http://sodipodi.sourceforge.net/DTD/sodipodi-0.0.dtd"},
{Short: "@sketch", Full: "http://www.bohemiancoding.com/sketch/ns"},
}
SVGDictionary is the well-known set of XML namespace URI shortcuts that pkg/svg uses to compress the `namespace` column.
Tokens follow TDTP v1.4 dictionary semantics: whole-cell match only, `@` sigil, ASCII letters/digits/underscore after the sigil.
Keep this list short and stable — adding entries is a one-way commitment (existing TDTP-SVG files in the wild that use a token would re-parse with the old meaning if we ever changed the URI). Adding NEW tokens is safe; renaming or removing is not.
Functions ¶
func BuildSchema ¶
BuildSchema returns the TDTP schema for SVG rows. ID is the key.
func ToPackets ¶
func ToPackets(rows []SVGRow) ([]*packet.DataPacket, error)
ToPackets converts []SVGRow into TDTP DataPackets using the standard generator. Multiple packets are returned if the byte size exceeds the generator's max message size (default ~1.9 MB).
The SVG dictionary (well-known namespace URI shortcuts) is attached to the schema so that the resulting packet is self-describing — any v1.4 consumer can reverse the contraction without out-of-band knowledge.
Types ¶
type SVGRow ¶
type SVGRow struct {
// --- Structural metadata (6 fields) ---
// Tree is reconstructed from (ParentID, OrderIdx) alone.
// Materialized path was dropped: a 50-byte derived string per row
// is bloat — we already build the tree during parse/write anyway.
ID int64
ParentID int64 // 0 = root (the <svg> element itself)
OrderIdx int // 1-based index among siblings
Tag string // "svg", "rect", "g", "_text_node", ...
Namespace string // XML namespace URI; "" = default SVG
TextContent string // for _text_node, or text inside elements
// --- Wide-sparse overflow (1 field) ---
// JSON object with any attribute that does NOT have a dedicated
// column below. Keys are the literal attribute names (including
// namespace prefixes like "inkscape:label"). Empty if no overflow.
AttrsJSON string
// --- Wide attributes (17 most common in real SVG) ---
IDAttr string // <... id="...">
Class string
Fill string
Stroke string
StrokeWidth string
D string // <path d="...">
Transform string
Style string
Width string
Height string
X string
Y string
Cx string
Cy string
R string
ViewBox string
Href string
}
SVGRow is the in-memory representation of one TDTP row. Field order in this struct DEFINES the column order in the schema — keep it stable, append-only.
func FromPacket ¶
func FromPacket(pkt *packet.DataPacket) ([]SVGRow, error)
FromPacket reverses ToPackets for a single packet, returning the rows in the order they were stored. Caller is responsible for concatenating rows from multi-part packets in part-number order.
Handles both packet shapes: parser.Parse output (Data.Rows populated) and generator.GenerateReference output (rawRows fast-path, materialized on demand). This way the same code path works for both --to-svg reading from disk and unit tests staying in memory.
func Parse ¶
Parse reads an SVG document and produces a flat slice of SVGRow. Tree structure is encoded via (parent_id, order_idx). Mixed-content text becomes synthetic rows with Tag=TagTextNode.
Streaming via xml.Decoder.Token(): memory use is O(tree depth), not O(file size), so this scales to large CAD-style SVGs.
Source Files