Zip-process NPM

zip-process

Tiny module for easy modify & repack files in zip archives and zip-containers like Excel files. Based on JSZip.

Install

This is a Node.js module available through the npm registry. Installation is done using the npm install command:

$ npm install zip-process

API

Imagine that we have .xlsx file (zip container). And need to change all occurences 'John' to 'Fedor'. !Don't do that if not sure for avoid side-effects.

Node.js

const zipProcess = require('zip-process');
const fs = require(fs);

// zipProcess options
const options = {}; // All default

// zipProcess calbacks (processors)
const callbacks = {	
  // We split binary && text processing, for binary use key 'binary', for text files 'string'
  string: { 
    // aplly path filter we need to check all .xml && .xml.rels files
    filter: relativePath =>  !!/\.xml(\.rels)?$/.test(relativePath),
			
    // just change it, and return new value
    callback: (data, zipFileName) =>  data && data.replace(/\bJohn\b/g, 'Fedor')
  }
}


fs.readFile('./john.xlsx', function(err, source) {

  if (err) { throw err; }

  zipProcess(source, options, callbacks).then( out => {

    const changed = source !== out;

    if (changed) {
      fs.writeFileSync('./fedor.xlsx', out);
    }

  }) ; // enf of zipProcess

}); // end of fs.readFile

VanillaJS with FileSaver

var xhr = new XMLHTTPRequest();
xhr.open("GET", './john.xlsx', true);
xhr.responseType = 'arraybuffer';
xhr.addEventListener('load',function(){
  if (xhr.status === 200){

    zipProcess(xhr.response, {}, {
      string: {
        filter: relativePath =>  !!/\.xml(\.rels)?$/.test(relativePath),
        callback: data =>  data && data.replace(/\bJohn\b/g, 'Fedor')
      }
    }).then((result) => {

      FileSaver.saveAs(
        result 
        'fedor.xlsx',
        true
       );

    });
  }
})
xhr.send();

As your might guess, I wrote this module special for work with Excel files, but other types of zip works fine too ;)

function `zipProcess(content, options, callbacks)`

Process zip content (binary) and returns promise. Where promise get in parameter new packed content.

content parameter

Zip file content (readed as binary).

options parameter

If ommited, blank or undefined, defaults options will be used.

Awailable options:

removeSignature: Remove file if callback return exactly signature (default null)
compression: compress file 'DEFLATE' or not 'STORE' (default 'DEFLATE') as options.compession in JSZip.generateAsync
extendOptions : all other options for options in JSZip.generateAsync (default {})
type: (default: for Node application 'nodebuffer', for browser 'blob' ) as options.type in JSZip.generateAsync

callbacks parameter

Hash of {string, binary, ...} with same structure {filter, callback, options}:

{
  string: {
    filter: function(relativePath, fileInfo){ ... },
      callback: function(fileContent, relativePath, zipObject){ ... },
      options: { ... }
    },
    binary: {
      filter: ...
      callback: ...
      options: ...
    },
}

Section keys: `{string}`, `{binary}` and others

String section used for work with text files. This mean that this files will be decoded by zipObject.async('string'). So binary files will be decoded by zipObject.async('unit8array'). Hint! you can use any other key for section, it will be translated to zipObject.async(). Available types you can see in JSZip documentation.

Warning! I dont know how national encoded files will works. I prefer to use UTF8 any way.

Section structure

`filter: function(relativePath, fileInfo)`

This function allow process only files within zip that you want. Realized directly by JSZip.filter.

If ommited, behaviour defined by section keys:

string - files with extension where defined mime-charset ( mime.lookup(mime.charset(fileName)) ) or xml or xml based extensions
binary - all files which not string
any other key - all files in archive

`callback: function(fileContent, relativePath, zipObject)`

If ommited, nothing changed.

This call back must return changed or unchanged content, undefined or signature for remove this file from archive.

If content changed, target file will be repacked with new content.
If content unchanged or undefined will nothing changed.
If content === options.removeSignature (default null), target file will be removed from archive.