awaforge

pdfStructTree

AGPL-3.0-onlyRelease 2L4

Structure Tree Root — ISO 32000-2 §14.7.2, basis of PDF/UA-2 (ISO 14289-2).

Module pdfStructTree | Source packages/front/office/pdf/src/tagged/structTree.js | Deps pdfErrors, pdfParser | Worker-safe yes

Types the /Type /StructTreeRoot dict referenced by the Catalog. Carries /K (root kid(s)), /IDTree (ID name tree), /ParentTree (number tree mapping MCIDs and OBJRs), /ParentTreeNextKey, /RoleMap, /ClassMap, /Namespaces (PDF 2.0), /AF, /PronunciationLexicon. /K is normalized to Array<ref|dict>.

Resolve

const st = runtime.resolve('pdfStructTree');
// Returns: { typeStructTreeRoot }

API

Method Signature Returns
typeStructTreeRoot (dict) => StructTreeRoot Typing of the root.

Shape

{
    kids: Array<ref|dict>,
    idTree, parentTree,
    parentTreeNextKey: number,
    roleMap, classMap, namespaces, af, pronunciationLexicon,
    raw, _extras
}

Examples

Walking from the Catalog

const st = runtime.resolve('pdfStructTree');
const root = st.typeStructTreeRoot(doc._raw.resolve(doc.catalog.structTreeRoot));
for (const kid of root.kids) {
    const el = runtime.resolve('pdfStructElement').typeStructElement(
        kid.type === 'ref' ? doc._raw.resolve(kid) : kid
    );
}

Mapping custom roles

const rm = runtime.resolve('pdfRoleMap').typeRoleMap(root.roleMap);
rm.map.MyCustomP;   // -> 'P'

Errors

Code Class When
pdf/tagged/struct-tree/not-dict ParseError Argument is not a dict.
pdf/tagged/struct-tree/bad-type ParseError /Type ≠ /StructTreeRoot.
pdf/tagged/struct-tree/bad-kid ParseError /K is neither ref/dict, or an array with an invalid entry.

See also