feat(ZUGFERD): Add dedicated ZUGFERD v1/v2 support and refine invoice format detection logic
This commit is contained in:
78
ts/formats/pdf/extractors/associated.extractor.ts
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78
ts/formats/pdf/extractors/associated.extractor.ts
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@ -0,0 +1,78 @@
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import { PDFDocument, PDFDict, PDFName, PDFRawStream, PDFArray, PDFString } from 'pdf-lib';
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import { BaseXMLExtractor } from './base.extractor.js';
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/**
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* Associated files extractor for PDF/A-3 documents
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* Extracts XML from associated files (AF entry in the catalog)
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* Particularly useful for ZUGFeRD v1 and some Factur-X documents
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*/
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export class AssociatedFilesExtractor extends BaseXMLExtractor {
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/**
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* Extract XML from a PDF buffer using associated files
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* @param pdfBuffer PDF buffer
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* @returns XML content or null if not found
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*/
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public async extractXml(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
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try {
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const pdfDoc = await PDFDocument.load(pdfBuffer);
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// Try to find associated files via the AF entry in the catalog
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const afArray = pdfDoc.catalog.lookup(PDFName.of('AF'));
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if (!(afArray instanceof PDFArray)) {
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console.warn('No AF (Associated Files) entry found in PDF catalog');
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return null;
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}
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// Process each associated file
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for (let i = 0; i < afArray.size(); i++) {
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const fileSpec = afArray.lookup(i);
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if (!(fileSpec instanceof PDFDict)) {
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continue;
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}
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// Get the file name
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const fileNameObj = fileSpec.lookup(PDFName.of('F')) || fileSpec.lookup(PDFName.of('UF'));
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if (!(fileNameObj instanceof PDFString)) {
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continue;
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}
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const fileName = fileNameObj.decodeText();
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// Check if it's a known invoice XML file name
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const isKnownFileName = this.knownFileNames.some(
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knownName => fileName.toLowerCase() === knownName.toLowerCase()
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);
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// Check if it's any XML file or has invoice-related keywords
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const isXmlFile = fileName.toLowerCase().endsWith('.xml') ||
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fileName.toLowerCase().includes('zugferd') ||
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fileName.toLowerCase().includes('factur-x') ||
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fileName.toLowerCase().includes('xrechnung') ||
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fileName.toLowerCase().includes('invoice');
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if (isKnownFileName || isXmlFile) {
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// Get the embedded file dictionary
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const efDict = fileSpec.lookup(PDFName.of('EF'));
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if (!(efDict instanceof PDFDict)) {
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continue;
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}
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// Get the file stream
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const fileStream = efDict.lookup(PDFName.of('F'));
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if (fileStream instanceof PDFRawStream) {
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const xmlContent = await this.extractXmlFromStream(fileStream, fileName);
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if (xmlContent) {
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return xmlContent;
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}
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}
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}
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}
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console.warn('No valid XML found in associated files');
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return null;
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} catch (error) {
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console.error('Error in associated files extraction:', error);
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return null;
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}
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}
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}
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177
ts/formats/pdf/extractors/base.extractor.ts
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177
ts/formats/pdf/extractors/base.extractor.ts
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@ -0,0 +1,177 @@
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import { PDFDocument, PDFDict, PDFName, PDFRawStream, PDFArray, PDFString } from 'pdf-lib';
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import * as pako from 'pako';
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/**
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* Base class for PDF XML extractors with common functionality
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*/
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export abstract class BaseXMLExtractor {
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/**
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* Known XML file names for different invoice formats
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*/
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protected readonly knownFileNames = [
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'factur-x.xml',
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'zugferd-invoice.xml',
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'ZUGFeRD-invoice.xml',
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'xrechnung.xml'
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];
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/**
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* Known XML formats to validate extracted content
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*/
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protected readonly knownFormats = [
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'CrossIndustryInvoice',
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'CrossIndustryDocument',
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'Invoice',
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'CreditNote',
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'ubl:Invoice',
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'ubl:CreditNote',
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'rsm:CrossIndustryInvoice',
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'rsm:CrossIndustryDocument',
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'ram:CrossIndustryDocument',
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'urn:un:unece:uncefact',
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'urn:ferd:CrossIndustryDocument',
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'urn:zugferd',
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'urn:factur-x',
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'factur-x.eu',
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'ZUGFeRD'
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];
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/**
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* Known XML end tags for extracting content from strings
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*/
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protected readonly knownEndTags = [
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'</CrossIndustryInvoice>',
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'</CrossIndustryDocument>',
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'</Invoice>',
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'</CreditNote>',
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'</rsm:CrossIndustryInvoice>',
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'</rsm:CrossIndustryDocument>',
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'</ram:CrossIndustryDocument>',
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'</ubl:Invoice>',
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'</ubl:CreditNote>'
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];
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/**
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* Extract XML from a PDF buffer
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* @param pdfBuffer PDF buffer
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* @returns XML content or null if not found
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*/
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public abstract extractXml(pdfBuffer: Uint8Array | Buffer): Promise<string | null>;
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/**
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* Check if an XML string is valid
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* @param xmlString XML string to check
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* @returns True if the XML is valid
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*/
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protected isValidXml(xmlString: string): boolean {
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try {
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// Basic checks for XML validity
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if (!xmlString || typeof xmlString !== 'string') {
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return false;
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}
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// Check if it starts with XML declaration
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if (!xmlString.includes('<?xml')) {
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return false;
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}
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// Check if the XML string contains known invoice formats
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const hasKnownFormat = this.knownFormats.some(format => xmlString.includes(format));
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if (!hasKnownFormat) {
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return false;
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}
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// Check if the XML string contains binary data or invalid characters
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const invalidChars = ['\u0000', '\u0001', '\u0002', '\u0003', '\u0004', '\u0005'];
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const hasBinaryData = invalidChars.some(char => xmlString.includes(char));
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if (hasBinaryData) {
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return false;
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}
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// Check if the XML string is too short
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if (xmlString.length < 100) {
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return false;
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}
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return true;
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} catch (error) {
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console.error('Error validating XML:', error);
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return false;
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}
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}
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/**
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* Extract XML from a string
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* @param text Text to extract XML from
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* @param startIndex Index to start extraction from
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* @returns XML content or null if not found
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*/
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protected extractXmlFromString(text: string, startIndex: number = 0): string | null {
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try {
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// Find the start of the XML document
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const xmlStartIndex = text.indexOf('<?xml', startIndex);
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if (xmlStartIndex === -1) {
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return null;
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}
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// Try to find the end of the XML document
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let xmlEndIndex = -1;
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for (const endTag of this.knownEndTags) {
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const endIndex = text.indexOf(endTag, xmlStartIndex);
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if (endIndex !== -1) {
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xmlEndIndex = endIndex + endTag.length;
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break;
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}
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}
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if (xmlEndIndex === -1) {
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return null;
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}
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// Extract the XML content
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return text.substring(xmlStartIndex, xmlEndIndex);
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} catch (error) {
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console.error('Error extracting XML from string:', error);
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return null;
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}
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}
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/**
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* Decompress and decode XML content from a PDF stream
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* @param stream PDF stream containing XML data
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* @param fileName Name of the file (for logging)
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* @returns XML content or null if not valid
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*/
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protected async extractXmlFromStream(stream: PDFRawStream, fileName: string): Promise<string | null> {
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try {
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// Try to decompress with pako
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const compressedBytes = stream.getContents().buffer;
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try {
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const decompressedBytes = pako.inflate(compressedBytes);
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const xmlContent = new TextDecoder('utf-8').decode(decompressedBytes);
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if (this.isValidXml(xmlContent)) {
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console.log(`Successfully extracted decompressed XML from PDF file. File name: ${fileName}`);
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return xmlContent;
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}
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} catch (decompressError) {
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// Decompression failed, try without decompression
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console.log(`Decompression failed for ${fileName}, trying without decompression...`);
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}
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// Try without decompression
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const rawBytes = stream.getContents();
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const rawContent = new TextDecoder('utf-8').decode(rawBytes);
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if (this.isValidXml(rawContent)) {
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console.log(`Successfully extracted uncompressed XML from PDF file. File name: ${fileName}`);
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return rawContent;
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}
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return null;
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} catch (error) {
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console.error('Error extracting XML from stream:', error);
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return null;
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}
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}
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}
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4
ts/formats/pdf/extractors/index.ts
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4
ts/formats/pdf/extractors/index.ts
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@ -0,0 +1,4 @@
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export * from './base.extractor.js';
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export * from './standard.extractor.js';
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export * from './associated.extractor.js';
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export * from './text.extractor.js';
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86
ts/formats/pdf/extractors/standard.extractor.ts
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86
ts/formats/pdf/extractors/standard.extractor.ts
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@ -0,0 +1,86 @@
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import { PDFDocument, PDFDict, PDFName, PDFRawStream, PDFArray, PDFString } from 'pdf-lib';
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import { BaseXMLExtractor } from './base.extractor.js';
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/**
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* Standard PDF XML extractor that extracts XML from embedded files
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* Works with PDF/A-3 documents that follow the standard for embedding files
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*/
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export class StandardXMLExtractor extends BaseXMLExtractor {
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/**
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* Extract XML from a PDF buffer using standard PDF/A-3 embedded files
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* @param pdfBuffer PDF buffer
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* @returns XML content or null if not found
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*/
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public async extractXml(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
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try {
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const pdfDoc = await PDFDocument.load(pdfBuffer);
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// Get the document's metadata dictionary
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const namesDictObj = pdfDoc.catalog.lookup(PDFName.of('Names'));
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if (!(namesDictObj instanceof PDFDict)) {
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console.warn('No Names dictionary found in PDF! This PDF does not contain embedded files.');
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return null;
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}
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// Get the embedded files dictionary
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const embeddedFilesDictObj = namesDictObj.lookup(PDFName.of('EmbeddedFiles'));
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if (!(embeddedFilesDictObj instanceof PDFDict)) {
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console.warn('No EmbeddedFiles dictionary found! This PDF does not contain embedded files.');
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return null;
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}
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// Get the names array
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const filesSpecObj = embeddedFilesDictObj.lookup(PDFName.of('Names'));
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if (!(filesSpecObj instanceof PDFArray)) {
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console.warn('No files specified in EmbeddedFiles dictionary!');
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return null;
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}
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// Try to find an XML file in the embedded files
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for (let i = 0; i < filesSpecObj.size(); i += 2) {
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const fileNameObj = filesSpecObj.lookup(i);
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const fileSpecObj = filesSpecObj.lookup(i + 1);
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if (!(fileNameObj instanceof PDFString) || !(fileSpecObj instanceof PDFDict)) {
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continue;
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}
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// Get the filename as string
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const fileName = fileNameObj.decodeText();
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// Check if it's a known invoice XML file name
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const isKnownFileName = this.knownFileNames.some(
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knownName => fileName.toLowerCase() === knownName.toLowerCase()
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);
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// Check if it's any XML file or has invoice-related keywords
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const isXmlFile = fileName.toLowerCase().endsWith('.xml') ||
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fileName.toLowerCase().includes('zugferd') ||
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fileName.toLowerCase().includes('factur-x') ||
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fileName.toLowerCase().includes('xrechnung') ||
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fileName.toLowerCase().includes('invoice');
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if (isKnownFileName || isXmlFile) {
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const efDictObj = fileSpecObj.lookup(PDFName.of('EF'));
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if (!(efDictObj instanceof PDFDict)) {
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continue;
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}
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const fileStream = efDictObj.lookup(PDFName.of('F'));
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if (fileStream instanceof PDFRawStream) {
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const xmlContent = await this.extractXmlFromStream(fileStream, fileName);
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if (xmlContent) {
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return xmlContent;
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}
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}
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}
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}
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console.warn('No valid XML found in embedded files');
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return null;
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} catch (error) {
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console.error('Error in standard extraction:', error);
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return null;
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}
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}
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}
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55
ts/formats/pdf/extractors/text.extractor.ts
Normal file
55
ts/formats/pdf/extractors/text.extractor.ts
Normal file
@ -0,0 +1,55 @@
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import { BaseXMLExtractor } from './base.extractor.js';
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/**
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* Text-based XML extractor for PDF documents
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* Extracts XML by searching for XML patterns in the PDF text
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* Used as a fallback when other extraction methods fail
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*/
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export class TextXMLExtractor extends BaseXMLExtractor {
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/**
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* Extract XML from a PDF buffer by searching for XML patterns in the text
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* @param pdfBuffer PDF buffer
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* @returns XML content or null if not found
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*/
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public async extractXml(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
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try {
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// Convert buffer to string and look for XML patterns
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// Increase the search range to handle larger PDFs
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const pdfString = Buffer.from(pdfBuffer).toString('utf8', 0, Math.min(pdfBuffer.length, 50000));
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// Look for common XML patterns in the PDF
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const xmlPatterns = [
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/<\?xml[^>]*\?>/i,
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/<CrossIndustryInvoice[^>]*>/i,
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/<CrossIndustryDocument[^>]*>/i,
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/<Invoice[^>]*>/i,
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/<CreditNote[^>]*>/i,
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/<rsm:CrossIndustryInvoice[^>]*>/i,
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/<rsm:CrossIndustryDocument[^>]*>/i,
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/<ram:CrossIndustryDocument[^>]*>/i,
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/<ubl:Invoice[^>]*>/i,
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/<ubl:CreditNote[^>]*>/i
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];
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|
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for (const pattern of xmlPatterns) {
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const match = pdfString.match(pattern);
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if (match && match.index !== undefined) {
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console.log(`Found XML pattern in PDF: ${match[0]}`);
|
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|
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// Try to extract the XML content
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const xmlContent = this.extractXmlFromString(pdfString, match.index);
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if (xmlContent && this.isValidXml(xmlContent)) {
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console.log('Successfully extracted XML from PDF text');
|
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return xmlContent;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
console.warn('No valid XML found in PDF text');
|
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return null;
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} catch (error) {
|
||||
console.error('Error in text-based extraction:', error);
|
||||
return null;
|
||||
}
|
||||
}
|
||||
}
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@ -1,30 +1,54 @@
|
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import { PDFDocument, PDFDict, PDFName, PDFRawStream, PDFArray, PDFString } from 'pdf-lib';
|
||||
import * as pako from 'pako';
|
||||
import {
|
||||
BaseXMLExtractor,
|
||||
StandardXMLExtractor,
|
||||
AssociatedFilesExtractor,
|
||||
TextXMLExtractor
|
||||
} from './extractors/index.js';
|
||||
|
||||
/**
|
||||
* Class for extracting XML from PDF files
|
||||
* Main PDF extractor class that orchestrates the extraction process
|
||||
* Uses multiple specialized extractors in sequence to maximize success rate
|
||||
*/
|
||||
export class PDFExtractor {
|
||||
private extractors: BaseXMLExtractor[] = [];
|
||||
|
||||
/**
|
||||
* Extracts XML from a PDF buffer
|
||||
* Constructor initializes the chain of extractors
|
||||
*/
|
||||
constructor() {
|
||||
// Add extractors in order of preference/likelihood of success
|
||||
this.extractors.push(
|
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new StandardXMLExtractor(), // Standard PDF/A-3 embedded files
|
||||
new AssociatedFilesExtractor(), // Associated files (ZUGFeRD v1, some Factur-X)
|
||||
new TextXMLExtractor() // Text-based extraction (fallback)
|
||||
);
|
||||
}
|
||||
|
||||
/**
|
||||
* Extract XML from a PDF buffer
|
||||
* Tries multiple extraction methods in sequence
|
||||
* @param pdfBuffer PDF buffer
|
||||
* @returns XML content or null if not found
|
||||
*/
|
||||
public async extractXml(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
|
||||
try {
|
||||
// First try the standard extraction
|
||||
const standardXml = await this.standardExtraction(pdfBuffer);
|
||||
if (standardXml && this.isValidXml(standardXml)) {
|
||||
return standardXml;
|
||||
console.log('Starting XML extraction from PDF...');
|
||||
|
||||
// Try each extractor in sequence
|
||||
for (const extractor of this.extractors) {
|
||||
const extractorName = extractor.constructor.name;
|
||||
console.log(`Trying extraction with ${extractorName}...`);
|
||||
|
||||
const xml = await extractor.extractXml(pdfBuffer);
|
||||
if (xml) {
|
||||
console.log(`Successfully extracted XML using ${extractorName}`);
|
||||
return xml;
|
||||
}
|
||||
|
||||
console.log(`Extraction with ${extractorName} failed, trying next method...`);
|
||||
}
|
||||
|
||||
// If standard extraction fails, try alternative methods
|
||||
const alternativeXml = await this.alternativeExtraction(pdfBuffer);
|
||||
if (alternativeXml && this.isValidXml(alternativeXml)) {
|
||||
return alternativeXml;
|
||||
}
|
||||
|
||||
// If all extraction methods fail, return null
|
||||
// If all extractors fail, return null
|
||||
console.warn('All extraction methods failed, no valid XML found in PDF');
|
||||
return null;
|
||||
} catch (error) {
|
||||
@ -33,255 +57,7 @@ export class PDFExtractor {
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Standard extraction method using PDF-lib
|
||||
* @param pdfBuffer PDF buffer
|
||||
* @returns XML content or null if not found
|
||||
*/
|
||||
private async standardExtraction(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
|
||||
try {
|
||||
const pdfDoc = await PDFDocument.load(pdfBuffer);
|
||||
|
||||
// Get the document's metadata dictionary
|
||||
const namesDictObj = pdfDoc.catalog.lookup(PDFName.of('Names'));
|
||||
if (!(namesDictObj instanceof PDFDict)) {
|
||||
console.warn('No Names dictionary found in PDF! This PDF does not contain embedded files.');
|
||||
return null;
|
||||
}
|
||||
|
||||
const embeddedFilesDictObj = namesDictObj.lookup(PDFName.of('EmbeddedFiles'));
|
||||
if (!(embeddedFilesDictObj instanceof PDFDict)) {
|
||||
console.warn('No EmbeddedFiles dictionary found! This PDF does not contain embedded files.');
|
||||
return null;
|
||||
}
|
||||
|
||||
const filesSpecObj = embeddedFilesDictObj.lookup(PDFName.of('Names'));
|
||||
if (!(filesSpecObj instanceof PDFArray)) {
|
||||
console.warn('No files specified in EmbeddedFiles dictionary!');
|
||||
return null;
|
||||
}
|
||||
|
||||
// Try to find an XML file in the embedded files
|
||||
let xmlFile: PDFRawStream | undefined;
|
||||
let xmlFileName: string | undefined;
|
||||
|
||||
for (let i = 0; i < filesSpecObj.size(); i += 2) {
|
||||
const fileNameObj = filesSpecObj.lookup(i);
|
||||
const fileSpecObj = filesSpecObj.lookup(i + 1);
|
||||
|
||||
if (!(fileNameObj instanceof PDFString)) {
|
||||
continue;
|
||||
}
|
||||
if (!(fileSpecObj instanceof PDFDict)) {
|
||||
continue;
|
||||
}
|
||||
|
||||
// Get the filename as string
|
||||
const fileName = fileNameObj.toString();
|
||||
|
||||
// Check if it's an XML file (checking both extension and known standard filenames)
|
||||
if (fileName.toLowerCase().includes('.xml') ||
|
||||
fileName.toLowerCase().includes('factur-x') ||
|
||||
fileName.toLowerCase().includes('zugferd') ||
|
||||
fileName.toLowerCase().includes('xrechnung')) {
|
||||
|
||||
const efDictObj = fileSpecObj.lookup(PDFName.of('EF'));
|
||||
if (!(efDictObj instanceof PDFDict)) {
|
||||
continue;
|
||||
}
|
||||
|
||||
const maybeStream = efDictObj.lookup(PDFName.of('F'));
|
||||
if (maybeStream instanceof PDFRawStream) {
|
||||
// Found an XML file - save it
|
||||
xmlFile = maybeStream;
|
||||
xmlFileName = fileName;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// If no XML file was found, return null
|
||||
if (!xmlFile) {
|
||||
console.warn('No embedded XML file found in the PDF!');
|
||||
return null;
|
||||
}
|
||||
|
||||
// Decompress and decode the XML content
|
||||
try {
|
||||
// Try to decompress with pako
|
||||
const xmlCompressedBytes = xmlFile.getContents().buffer;
|
||||
const xmlBytes = pako.inflate(xmlCompressedBytes);
|
||||
const xmlContent = new TextDecoder('utf-8').decode(xmlBytes);
|
||||
|
||||
// Check if the XML content is valid
|
||||
if (this.isValidXml(xmlContent)) {
|
||||
console.log(`Successfully extracted XML from PDF file. File name: ${xmlFileName}`);
|
||||
return xmlContent;
|
||||
}
|
||||
|
||||
// If we get here, the XML content is not valid, try without decompression
|
||||
console.log('Decompression succeeded but XML is not valid, trying without decompression...');
|
||||
const rawXmlBytes = xmlFile.getContents();
|
||||
const rawXmlContent = new TextDecoder('utf-8').decode(rawXmlBytes);
|
||||
|
||||
if (this.isValidXml(rawXmlContent)) {
|
||||
console.log(`Successfully extracted uncompressed XML from PDF file. File name: ${xmlFileName}`);
|
||||
return rawXmlContent;
|
||||
}
|
||||
|
||||
// If we get here, neither the decompressed nor the raw XML content is valid
|
||||
console.log('Neither decompressed nor raw XML content is valid');
|
||||
return null;
|
||||
} catch (decompressError) {
|
||||
// Decompression failed, try without decompression
|
||||
console.log('Decompression failed, trying without decompression...');
|
||||
try {
|
||||
const xmlBytes = xmlFile.getContents();
|
||||
const xmlContent = new TextDecoder('utf-8').decode(xmlBytes);
|
||||
|
||||
if (this.isValidXml(xmlContent)) {
|
||||
console.log(`Successfully extracted uncompressed XML from PDF file. File name: ${xmlFileName}`);
|
||||
return xmlContent;
|
||||
}
|
||||
|
||||
// If we get here, the XML content is not valid
|
||||
console.log('Uncompressed XML content is not valid');
|
||||
return null;
|
||||
} catch (decodeError) {
|
||||
console.error('Error decoding XML content:', decodeError);
|
||||
return null;
|
||||
}
|
||||
}
|
||||
} catch (error) {
|
||||
console.error('Error in standard extraction:', error);
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Alternative extraction method using string search
|
||||
* @param pdfBuffer PDF buffer
|
||||
* @returns XML content or null if not found
|
||||
*/
|
||||
private async alternativeExtraction(pdfBuffer: Uint8Array | Buffer): Promise<string | null> {
|
||||
try {
|
||||
// Convert buffer to string and look for XML patterns
|
||||
const pdfString = Buffer.from(pdfBuffer).toString('utf8', 0, Math.min(pdfBuffer.length, 10000));
|
||||
|
||||
// Look for common XML patterns in the PDF
|
||||
const xmlPatterns = [
|
||||
/<\?xml[^>]*\?>/i,
|
||||
/<CrossIndustryInvoice[^>]*>/i,
|
||||
/<Invoice[^>]*>/i,
|
||||
/<CreditNote[^>]*>/i,
|
||||
/<rsm:CrossIndustryInvoice[^>]*>/i
|
||||
];
|
||||
|
||||
for (const pattern of xmlPatterns) {
|
||||
const match = pdfString.match(pattern);
|
||||
if (match) {
|
||||
console.log(`Found XML pattern in PDF: ${match[0]}`);
|
||||
|
||||
// Try to extract the XML content
|
||||
const xmlContent = this.extractXmlFromString(pdfString);
|
||||
if (xmlContent) {
|
||||
console.log('Successfully extracted XML from PDF string');
|
||||
return xmlContent;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return null;
|
||||
} catch (error) {
|
||||
console.error('Error in alternative extraction:', error);
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Extracts XML from a string
|
||||
* @param pdfString PDF string
|
||||
* @returns XML content or null if not found
|
||||
*/
|
||||
private extractXmlFromString(pdfString: string): string | null {
|
||||
try {
|
||||
// Look for XML start and end tags
|
||||
const xmlStartIndex = pdfString.indexOf('<?xml');
|
||||
if (xmlStartIndex === -1) {
|
||||
return null;
|
||||
}
|
||||
|
||||
// Try to find the end of the XML document
|
||||
const possibleEndTags = [
|
||||
'</CrossIndustryInvoice>',
|
||||
'</Invoice>',
|
||||
'</CreditNote>',
|
||||
'</rsm:CrossIndustryInvoice>'
|
||||
];
|
||||
|
||||
let xmlEndIndex = -1;
|
||||
for (const endTag of possibleEndTags) {
|
||||
const endIndex = pdfString.indexOf(endTag);
|
||||
if (endIndex !== -1) {
|
||||
xmlEndIndex = endIndex + endTag.length;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (xmlEndIndex === -1) {
|
||||
return null;
|
||||
}
|
||||
|
||||
// Extract the XML content
|
||||
return pdfString.substring(xmlStartIndex, xmlEndIndex);
|
||||
} catch (error) {
|
||||
console.error('Error extracting XML from string:', error);
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Checks if an XML string is valid
|
||||
* @param xmlString XML string to check
|
||||
* @returns True if the XML is valid
|
||||
*/
|
||||
private isValidXml(xmlString: string): boolean {
|
||||
try {
|
||||
// Check if the XML string contains basic XML structure
|
||||
if (!xmlString.includes('<?xml')) {
|
||||
return false;
|
||||
}
|
||||
|
||||
// Check if the XML string contains known invoice formats
|
||||
const knownFormats = [
|
||||
'CrossIndustryInvoice',
|
||||
'Invoice',
|
||||
'CreditNote',
|
||||
'ubl:Invoice',
|
||||
'ubl:CreditNote'
|
||||
];
|
||||
|
||||
const hasKnownFormat = knownFormats.some(format => xmlString.includes(format));
|
||||
if (!hasKnownFormat) {
|
||||
return false;
|
||||
}
|
||||
|
||||
// Check if the XML string contains binary data or invalid characters
|
||||
const invalidChars = ['\u0000', '\u0001', '\u0002', '\u0003', '\u0004', '\u0005'];
|
||||
const hasBinaryData = invalidChars.some(char => xmlString.includes(char));
|
||||
if (hasBinaryData) {
|
||||
return false;
|
||||
}
|
||||
|
||||
// Check if the XML string is too short
|
||||
if (xmlString.length < 100) {
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
} catch (error) {
|
||||
console.error('Error validating XML:', error);
|
||||
return false;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user