@flowaccount/easy-pdf-merge/lib/PDFMerger.js

A node module to merge PDFs. Uses Apache PDFBox library.

var fs = require('fs');
var exec = require('child_process').exec;
var path = require('path');

function checkSrc(src,callback){

      if(!Array.isArray(src))
      return callback('Source is not an Array');

      else if(src.length<2)
      return callback('There must be atleast 2 input files');

      var norm_src = [];

      for(var i=0;i<src.length;i++){

        if(typeof(src[i])==='string') {

            /*
            //Check if source file exists

            fs.stat(src[i],function(err,stats){

              if(err)
                return callback('Can\'t access file : ' + src[i]);

              if(!stats.isFile())
                return callback(src[i] + ' is not a File');

            });*/

            norm_src.push(`"${src[i]}"`);

        }

        else
          return callback(`Source : ${src[i]} + , is not a file name`);

      }

      callback(null,norm_src);

}

module.exports = function(src,dest,callback){

      var dirPathArr = __dirname.split(path.sep);
      var dirJrePathArr = __dirname.split(path.sep);

      var opsys = process.platform;
      if (opsys == "win32" || opsys == "win64") {
          opsys = "windows";
      } else {
          opsys = "linux";
      }

      dirPathArr.pop();
      dirPathArr.push('jar');
      dirPathArr.push('pdfbox.jar');
      dirJrePathArr.pop();
      dirJrePathArr.push('jre');
      dirJrePathArr.push(opsys);
      dirJrePathArr.push('bin');
      dirJrePathArr.push('java');

      var jarPath = dirPathArr.join(path.sep);
      var jrePath = dirJrePathArr.join(path.sep);

      var command = [`${jrePath} -jar "${jarPath}" PDFMerger`];

      checkSrc(src,function(err,norm_src){

          if(err)
          return callback(err);

          command = command.concat(norm_src);

          command.push(`"${dest}"`);

          var child = exec(command.join(' '),function(err,stdout,stderr){

              if(err)
              return callback(err);

              callback(null);

          });

          child.on('error',function(err){
            return callback(`Execution problem. ${err}`);
          });

      });

};