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  • License Apache-2.0

Creates a stream from PDF

Package Exports

  • pdf-stream

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (pdf-stream) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

pdf-stream

Code Climate

Creates a stream from PDF

Node.js module for streaming PDF text content.

Based on PDF.js library.

Table of Contents

Install

  npm i pdf-stream --save

Usage

Basic

Text stream from PDF file

  'use strict';
  
  const text = require('pdf-stream').text;
  
  // Load file contents to ArrayBuffer synchronously
  let file = './example.pdf';
  let pdf = new Uint8Array(fs.readFileSync(file));
  
  // Stream PDF text to stdout
  text(pdf)
    .pipe(process.stdout);

Text stream from PDF link

You need the XMLHttpRequest as global variable. Install the xhr2 library locally:

  npm i xhr2 --save
  'use strict';
  
  const text = require('pdf-stream').text;
  global.XMLHttpRequest = require('xhr2'); // for PDFJS
  
  let pdf = 'https://mozilla.github.io/pdf.js/web/compressed.tracemonkey-pldi-09.pdf';
    
  text(pdf)
    .pipe(process.stdout);

Text stream from PDF link with metadata as XML string

If you got error:

  ReferenceError: DOMParser is not defined

You need the DOMParser as global variable, because PDF.js use it for XML metadata parsing. Install the xmldom library locally:

  npm i xmldom --save
  'use strict';
  
  const text = require('pdf-stream').text;
  global.XMLHttpRequest = require('xhr2');        // File download 
  global.DOMParser = require('xmldom').DOMParser; // XML Metadata parsing
  
  let pdf = 'https://mozilla.github.io/pdf.js/web/compressed.tracemonkey-pldi-09.pdf';
    
  text(pdf)
    .pipe(process.stdout);

Advanced

Create transform class for replacing string

  'use strict';
  
  const Transform = require('stream').Transform;
  const pdf_stream = require('pdf-stream');
  const PDFReadable = pdf_stream.PDFReadable;
  const PDFStringifyTransform = pdf_stream.PDFStringifyTransform;
  
  let url = 'https://mozilla.github.io/pdf.js/web/compressed.tracemonkey-pldi-09.pdf';
  
  // Transform class for replacing strings
  class ReplaceTransform extends Transform {
    constructor(options) {
      super({
        writableObjectMode: true,
        readableObjectMode: true
      });
      this.from = options.from;
      this.to = options.to;
    }
  
    // For every object
    _transform(obj, encoding, cb) {
      // Get text content items
      if (typeof obj.textContent !== 'undefined'
        && Array.isArray(obj.textContent.items)) {
        obj.textContent.items.forEach((item, i) => {
          // Working with the PDF.js `textContent` object
          // Replace substring to another
          obj.textContent.items[i].str = item.str.replace(this.from, this.to);
        });
      }
  
      this.push(obj);
      cb();
    }
  
  }
  
  // Pipeline
  new PDFReadable(url)
    .pipe(new ReplaceTransform({
      from: /trace/gi,
      to: ':-)'
    }))
    .pipe(new PDFStringifyTransform()) // Convert stream from object to string 
    .pipe(process.stdout);

API

All methods are streams, use them with .pipe().

text(options)

alternative usage: text(pdf, whitespace)

Gets text stream from PDF.

Convert PDF to text, optionally can replace whitespaces.

Options:

  • pdf — URL or ArrayBuffer;
  • whitespace — the string that replaces the whitespace ␣. Replacement disabled by default.

In the PDF.js viewer whitespaces is an empty string. For making output comparable with the viewer use: text(pdf, '')

Return: {stream.Readable}

new PDFReadable(options)

alternative usage: new PDFReadable(pdf)

Making the Readable stream in object mode from PDF text content.

Options:

  • pdf — URL or ArrayBuffer;
  • inherit from stream.Readable options.

Return: {stream.Readable}

new PDFStringifyTransform(options)

alternative usage: new PDFStringifyTransform(whitespace)

Transform PDF text content object to string.

Options:

  • whitespace — the string that replaces the whitespace ␣. Replacement disabled by default;
  • inherit from stream.Transform options.

Return: {stream.Readable}

Contribute

Contributors are welcome. Open an issue or submit pull request.

Small note: If editing the README, please conform to the standard-readme specification.

License

Apache 2.0

© Sergey N