I have an array of strings which should be written to a .txt file. Also I need to press the resulting .txt file to .zip format using JSZip. At the client side, I was able to generate a 'text/plain' Blob using this array of strings and then I pressed this Blob to .zip format using JSZip. I need to do the same on the server side using node.js, but I realized that Blob is not available in node.js. I tried using 'Buffer' instead of Blob, and I got a binary file pressed as .zip; I am a beginner with node.js and couldn't understand the concepts of Buffer. Can I create a Blob in node.js? or Can I perform the same operations with node.js Buffer?
At the client side I can generate the zip file from Blob contents like this,
//stringsArray is an array of strings
var blob = new Blob( stringsArray, { type: "text/plain" } );
var zip = new JSZip();
zip.file( 'file.txt' , blob );
zip.generateAsync( { type: 'blob', pression: 'DEFLATE' } )
.then( function( zipFile ){
//do something with zipFile
}, function( error ){
console.log( 'Error in pression' );
} );
How can I do the same using Node.js?
I have an array of strings which should be written to a .txt file. Also I need to press the resulting .txt file to .zip format using JSZip. At the client side, I was able to generate a 'text/plain' Blob using this array of strings and then I pressed this Blob to .zip format using JSZip. I need to do the same on the server side using node.js, but I realized that Blob is not available in node.js. I tried using 'Buffer' instead of Blob, and I got a binary file pressed as .zip; I am a beginner with node.js and couldn't understand the concepts of Buffer. Can I create a Blob in node.js? or Can I perform the same operations with node.js Buffer?
At the client side I can generate the zip file from Blob contents like this,
//stringsArray is an array of strings
var blob = new Blob( stringsArray, { type: "text/plain" } );
var zip = new JSZip();
zip.file( 'file.txt' , blob );
zip.generateAsync( { type: 'blob', pression: 'DEFLATE' } )
.then( function( zipFile ){
//do something with zipFile
}, function( error ){
console.log( 'Error in pression' );
} );
How can I do the same using Node.js?
Share Improve this question asked Sep 25, 2017 at 9:40 HariVHariV 7071 gold badge11 silver badges17 bronze badges 3- 1 This code should run as is. Perhaps check the documentation for JSZip if they have a different method for Node. – user2652134 Commented Sep 25, 2017 at 10:15
- @BrahmaDev , I got 'Blob is not defined' error in node.js – HariV Commented Sep 25, 2017 at 10:47
- 1 Sorry for that, you'd have to use Buffer. The documentation would be a good point to research around this : stuk.github.io/jszip/documentation/api_jszip/… – user2652134 Commented Sep 25, 2017 at 10:51
1 Answer
Reset to default 12I found a solution for this. In my code, I wasn't using the proper method to convert the array of strings to node.js buffer ( I wasn't able to press the buffer using JSZip because the buffer was incorrect ). I tried the following code but it gave me an incorrect buffer,
//stringsArray is an array of strings
var buffer = Buffer.from( stringsArray );
The proper way is that, we have to convert each string to buffer first and then create a new buffer by appending all these sub buffers. I have created a custom buffer builder which will build a node.js buffer by appending strings to it. Following is the new method I have tried, and it worked for me.
var CustomBufferBuilder = function() {
this.parts = [];
this.totalLength = 0;
}
CustomBufferBuilder.prototype.append = function( part ) {
var tempBuffer = Buffer.from( part );
this.parts.push( tempBuffer );
this.totalLength += tempBuffer.length;
this.buffer = undefined;
};
CustomBufferBuilder.prototype.getBuffer = function() {
if ( !this.buffer ) {
this.buffer = Buffer.concat( this.parts, this.totalLength );
}
return this.buffer;
};
var customBufferBuilder = new CustomBufferBuilder();
var stringsArray = [ 'hello ', 'world.', '\nThis ', 'is', ' a ', 'test.' ];//stringsArray is an array of strings
var len = stringsArray.length;
for( var i = 0; i< len; i++ ){
customBufferBuilder.append( stringsArray[ i ] );
}
var bufferContent = customBufferBuilder.getBuffer();
var zip = new JSZip();
zip.file( 'test.txt', bufferContent, { binary : true } );
zip.generateAsync( { type : "nodebuffer", pression: 'DEFLATE' } )
.then( function callback( buffer ) {
fs.writeFile( 'test.zip', buffer, function( err ){
if( err ){
//tasks to perform in case of error
}
else{
//other logic
}
} );
}, function( e ) {
//tasks to perform in case of error
} );
As output, I got the zip file( test.zip ) and test.txt inside it. The test.txt file inside the zip file contains the following words, 'hello world.\nThis is a test.'.
Thanks @BrahmaDev for spending time to look into my question :)