How to Extract data from pdf file in nodejs

Question

I have already used 'pdf.js-extract' npm module to fetch data from pdf.

var PDFExtract = require('pdf.js-extract').PDFExtract;

var pdfExtract = new PDFExtract();
var filename="/home/aman/Downloads/sample_invoice.pdf"

pdfExtract.extract(filename , function (err, data) {
    if (err) return console.log(err);
    console.log(JSON.stringify(data));
});

But I am not getting the desired result. I want to fetch the relevant information from invoice pdf like tax, total amount paid, seller address and save the data fetched into the mongodb collection

Answer 1

You must write a function by invoice format (fn company1, fn company2...).

Here is an example with three different functions to retrieve data in the export of the pdf.js-extract module:

// Sample invoice
let sampleInvoice =
{
  "pages":
  [
    {
      "content":
      [
        {
          "x": 348.41,
          "y": 125.59899999999993,
          "str": "Invoice Number",
          "dir": "ltr",
          "width": 61.61760000000001,
          "height": 8.8,
          "fontName": "g_d0_f2"
        },
        {
          "x": 451.935,
          "y": 125.59899999999993,
          "str": "INV-3337",
          "dir": "ltr",
          "width": 37.171200000000006,
          "height": 8.8,
          "fontName": "g_d0_f2"
        }
      ]
    }
  ]
};


// Create alerts for test functions in browser
alert(searchByPosition(sampleInvoice.pages, 450, 125));
alert(searchByPrev(sampleInvoice.pages, 'Invoice Number'));
alert(searchByFormat(sampleInvoice.pages, /INV-\d+$/));


function searchByPosition(pages,x,y)
{
    // Set position range (difference max)
    let range = 10;

    // Init x and y positions
    x = Math.floor(x/range), y = Math.floor(y/range);

    // Loop in all pages
    for(let i = 0; i < pages.length; i++)

        // Loop in all content
        for(let j = 0; j < pages[i].content.length; j++)

            // Test position x and y and if match return content
            if(Math.floor(pages[i].content[j].x/range) == x && Math.floor(pages[i].content[j].y/range) == y)

                // Return result
                return pages[i].content[j].str;

    // No results found
    return 'NotFound';
}


function searchByPrev(pages,txt)
{
    // Init txt
    txt = txt.toLowerCase();

    // Loop in all pages
    for(let i = 0; i < pages.length; i++)

        // Loop in all content
        for(let j = 0; j < pages[i].content.length; j++)

            // Test text  and if match return next content
            // (If you write j-1, you can have searchByNext function)
            if(pages[i].content[j].str.toLowerCase() == txt && pages[i].content[j+1])

                // Return result
                return pages[i].content[j+1].str;

    // No results found
    return 'NotFound';
}


function searchByFormat(pages,regex)
{
    // Loop in all pages
    for(let i = 0; i < pages.length; i++)

        // Loop in all content
        for(let j = 0; j < pages[i].content.length; j++)

            // Test regex and if match return content
            if(regex.test(pages[i].content[j].str))

                // Return result
                return pages[i].content[j].str;

    // No results found
    return 'NotFound';
}

TRY HERE : https://jsfiddle.net/dkhqzg6s/