I have a node application that contains several downloadable links (when you click on the link a pdf file is downloaded), and these links are dynamically created/populated. I want to implement a feature where we can somehow download all files from these links in one go. I presume for this I will somehow need to create a zip file from all these links - would anyone know how to go about this?
you could use the fs and archiver module:
var fs = require('fs');
var archiver = require('archiver');
var output = fs.createWriteStream('./example.zip');
var archive = archiver('zip', {
gzip: true,
zlib: { level: 9 } // Sets the compression level.
});
archive.on('error', function(err) {
throw err;
});
// pipe archive data to the output file
archive.pipe(output);
// append files
archive.file('/path/to/file0.txt', {name: 'file0-or-change-this-whatever.txt'});
archive.file('/path/to/README.md', {name: 'foobar.md'});
//
archive.finalize();
Related
I am trying to unzip a file called Restart.Manager.zip which contains a single item, Restart Manager.app. This code seems to unzip the file correctly but upon launching the outputted .app folder, I get an error "The application “Restart Manager” can’t be opened."
const JSZip = require('jszip');
const fs = require('fs');
const jetpack = require('fs-jetpack');
const originalFs = require('original-fs');
async function extractZip(filePath, destination) {
fs.readFile(filePath, function(err, data) {
if (!err) {
var zip = new JSZip();
zip.loadAsync(data).then(function(contents) {
Object.keys(contents.files).forEach(function(filename) {
const file = zip.file(filename);
if (file) {
file.async('nodebuffer').then(function(content) {
var dest = destination + '/' + filename;
if (filename.endsWith('.asar')) {
originalFs.writeFileSync(dest, content)
} else {
jetpack.write(dest, content);
}
});
}
});
});
}
});
};
extractZip('/Users/me/Desktop/Restart.Manager.zip', '/Users/me/Desktop')
Manually unzipping the .zip file creates a working .app so I'm not sure where the code is messing up.
Here is the file on GitHub releases for testing: https://github.com/itw-creative-works/restart-manager-download-server/releases/download/installer/Restart.Manager.zip but feel free to use your own zipped .app file (although it should probably be an Electron app in which case you can find one here https://www.electronjs.org/apps)
I have tried zipping things like a .png and it unzips fine, which makes me think it is having problems with .app files or possibly the fact that the .app contains a .asar file which Electron supposedly has problems handling when it comes to the fs module: https://github.com/electron/electron/issues/1658
Basically I want to do the equivalent of this How to strip path while archiving with TAR but with the tar commands imported to NodeJS, so currently I'm doing this:
const gzip = zlib.createGzip();
const pack = new tar.Pack(prefix="");
const source = Readable.from('public/images/');
const destination = fs.createWriteStream('public/archive.tar.gz');
pipeline(source, pack, gzip, destination, (err) => {
if (err) {
console.error('An error occurred:', err);
process.exitCode = 1;
}
});
But doing so leaves me with files like: "/public/images/a.png" and "public/images/b.png", when what I want is files like "/a.png" and "/b.png". I want to know how I can add to this process to strip out the unneeded directories, while keeping the files where they are.
You need to change working directory:
// cwd The current working directory for creating the archive. Defaults to process.cwd().
new tar.Pack({ cwd: "./public/images" });
const source = Readable.from('');
Source: documentation of node-tar
Example: https://github.com/npm/node-tar/blob/main/test/pack.js#L93
I have an unzipped xlsx file, in it I edit some files to be able to generate a new xlsx file containing new data.
In linux to recompress the file in xlsx I just need to go into the terminal and type
find . -type f | xargs zip ../newfile.xlsx
into the folder where the xlsx files are.
The question now is how can I do this using node.js?
The solution is to compress a direct list of files contained in xlsx, for some reason if we try to compress the folder the file has corrupted.
The code looks like this if you use JSZIP
var fs = require('fs');
var JSZip = require("jszip");
var zip = new JSZip();
var file = [];
file.push("_rels/.rels");
file.push("docProps/core.xml");
file.push("docProps/app.xml");
file.push("docProps/custom.xml");
file.push("[Content_Types].xml");
file.push("xl/_rels/workbook.xml.rels");
file.push("xl/styles.xml");
file.push("xl/pivotTables/_rels/pivotTable3.xml.rels");
file.push("xl/pivotTables/_rels/pivotTable1.xml.rels");
file.push("xl/pivotTables/_rels/pivotTable2.xml.rels");
file.push("xl/pivotTables/pivotTable3.xml");
file.push("xl/pivotTables/pivotTable1.xml");
file.push("xl/pivotTables/pivotTable2.xml");
file.push("xl/workbook.xml");
file.push("xl/worksheets/_rels/sheet2.xml.rels");
file.push("xl/worksheets/_rels/sheet1.xml.rels");
file.push("xl/worksheets/_rels/sheet3.xml.rels");
file.push("xl/worksheets/sheet4.xml");
file.push("xl/worksheets/sheet1.xml");
file.push("xl/worksheets/sheet3.xml");
file.push("xl/worksheets/sheet2.xml");
file.push("xl/sharedStrings.xml");
file.push("xl/pivotCache/_rels/pivotCacheDefinition1.xml.rels");
file.push("xl/pivotCache/pivotCacheDefinition1.xml");
file.push("xl/pivotCache/pivotCacheRecords1.xml");
for (var i = 0; i < file.length; i++) {
zip.file(file[i], fs.readFileSync("/home/user/xlsx_FILES/"+file[i]));
}
zip.generateAsync({type:"blob"}).then(function(content) {
// see FileSaver.js
saveAs(content, "yourfile.xlsx");
});
Take a look at archiver, a compression library for nodejs. The docs for the library look like they are comprehensive. The library also allows you to append archives and take advantage of streaming api's for appending and creating new archives.
Here is an example snippet from their docs which shows how to use the library.
// require modules
var fs = require('fs');
var archiver = require('archiver');
// create a file to stream archive data to.
var output = fs.createWriteStream(__dirname + '/example.zip');
var archive = archiver('zip', {
store: true // Sets the compression method to STORE.
});
// listen for all archive data to be written
output.on('close', function() {
console.log(archive.pointer() + ' total bytes');
console.log('archiver has been finalized and the output file descriptor has closed.');
});
// good practice to catch this error explicitly
archive.on('error', function(err) {
throw err;
});
// pipe archive data to the file
archive.pipe(output);
I'd like to create an archive with archiver and put some files in it. Client's side, an user will click on a button and it'll generate the archive (server's side).
I'm using Express.js, this is my server side code where the archive will be generated. I did something like this :
app.get('/export/siteoccupancy', function(req,res){
if(_.isEmpty(req.query)){
res.status(404).send('requires a start and end date');
}else{
//getting paramas
var sDate = req.query.startDate;
var eDate = req.query.endDate;
}
var fs = require('fs');
var archiver = require('archiver');
var archive = archiver('zip');
archive.on('err',function(err){
res.status(500).send({error : err.message});
});
res.on('close',function(){
console.log('Archive size : %d b',archive.pointer());
return res.status(200).send('OK').end();
});
res.attachment('data-export.zip');
archive.pipe(res);
var stream = fs.createWriteStream("data-report.txt')");
stream.once('open',function(fd) {
stream.write('test1');
stream.write('\n test2');
stream.write('\n test3');
stream.end();
});
archive.append(stream);
archive.finalize();
});
This is totally new for me and I'd like to understand why the console tells me the stream file is empty ?
Error: append: entry name must be a non-empty string value
at Archiver.append
Regards
you can only append a readStream, because an archive can only take data from readstreams. You can use the method named archive.append, and you should pass as a second argument with the name property to name the file. Like so :
archive.append(myReadStream,{ name : 'myTest.txt'});
How we can check uploaded file extension in sails js?
I tried on skipper and multer but have no result.
any suggestion?
You should use saveAs options for each file before saving.
var md5 = require('md5');
module.exports = {
testUpload:function(req,res){
// setting allowed file types
var allowedTypes = ['image/jpeg', 'image/png'];
// skipper default upload directory .tmp/uploads/
var allowedDir = "../../assets/images";
// don not define dirname , use default path
req.file("uploadFiles").upload({
saveAs:function(file, cb) {
var d = new Date();
var extension = file.filename.split('.').pop();
// generating unique filename with extension
var uuid=md5(d.getMilliseconds())+"."+ extension;
// seperate allowed and disallowed file types
if(allowedTypes.indexOf(file.headers['content-type']) === -1) {
// save as disallowed files default upload path
cb(null,uuid);
}else{
// save as allowed files
cb(null,allowedDir+"/"+uuid);
}
}
},function whenDone(err,files){
return res.json({
files:files,
err:err
});
});
}
}
Just get uploaded files array and check last chunk of string after dot.
req.file('file').upload({
maxBytes: 2000000,
dirname: 'uploadFolder'
}, function (error, files) {
if (error) return sails.log.error(error);
// You have files array, so you can do this
files[0].fd.split('.').pop(); // You get extension
}
What is going on here? When upload is finished you will get array of files with their filenames. You can get data from that array and see where this file is located (full path).
The last thing is splitting string by dots and get last item from the array with pop() method.