Using node-csv and meteor-file to import CSV into

问题:

Been struggling for several hours now trying to import CSV, uploaded from client using meteor-file and converted to CSV using node-csv server-side. I basically need to populate my collection with data from a CSV file uploaded by the user.

/server/filehandler.js:

Meteor.methods({
'uploadFile': function (file) {

  if(file.start === 0) {
    console.log(file.name);
    console.log(file.type);
    console.log(file.size);            
  }

  file.save('/home/russell/tmp',{});
  var buffer = new Buffer(file.data);
  CSV().from(
          buffer.toString(),
          {comment: '#', delimiter: ',', quote: ''} 
      )
        .to.array( function(data){
          //console.log(data);

          for(var row=0; row<data.length; row++) {
              console.log(data[row]);
             newRecord = {
                  'firstname': data[row][0],
                  'lastname': data[row][1],
                  'email': data[row][2],
                  'emailshort': data[row][3],
                  'emailmain': data[row][4],
                  'domain': data[row][5]
              };
              console.log(newRecord);
              reas.insert(newRecord); // *** _dynamic_meteor ERROR here!
          }
        } );

 } // uploadFile
});

The console.log tells me that the CSV to array conversion is fine.

Collection reas is setup as a Collection in /lib/models.js - /lib is at the same level as /server & /client.

I've tried having a global variable outside of the Meteor.method() and storing the result of the conversion into that, and I've also tried using a Session.set(), but I just can't seem to get at the results of the conversion, outside of the method().

thanks.

UPDATED - 2013-10-11

My /libs/models.js looks like this:

reas = new Meteor.Collection("RegisteredEmailAddresses");

/*checks to see if the current user making the request to update is the admin user */
function adminUser(userId) {
    var adminUser = Meteor.users.findOne({username:"admin"});
                return (userId && adminUser && userId === adminUser._id);
            }

reas.allow({
    insert: function(userId, doc){
                        return adminUser(userId);
                    },
    update: function(userId, docs, fields, modifier){
                        return adminUser(userId);
                    },
    remove: function (userId, docs){
                        return adminUser(userId);
                    }
});

EUREKA MOMENT?!

Shouldn't that be /lib not /libs? Maybe reas is not being defined in time?

Updated 2013-10-09

If I leave in the line

reas.insert(newRecord);

I get the error message below. If I remove that line, i don't.

Error message:

W2036-20:56:29.463(1)? (STDERR) packages/mongo-livedata.js:1862
W2036-20:56:29.471(1)? (STDERR)         throw e;                                                              
W2036-20:56:29.475(1)? (STDERR)               ^
W2036-20:56:29.953(1)? (STDERR) Error: Meteor code must always run within a Fiber. Try wrapping callbacks that you pass to non-Meteor libraries with Meteor.bindEnvironment.
W2036-20:56:29.958(1)? (STDERR)     at Object.Meteor.bindEnvironment (packages/meteor/dynamics_nodejs.js:60)
W2036-20:56:29.958(1)? (STDERR)     at null.<anonymous> (packages/meteor/helpers.js:108)
W2036-20:56:29.959(1)? (STDERR)     at MongoConnection.(anonymous function) [as insert] (packages/mongo-livedata/mongo_driver.js:491)
W2036-20:56:29.964(1)? (STDERR)     at Meteor.Collection.(anonymous function) [as insert] (packages/mongo-livedata/collection.js:448)
W2036-20:56:29.965(1)? (STDERR)     at app/server/server.js:37:20
W2036-20:56:29.966(1)? (STDERR)     at null.<anonymous> (/home/russell/.meteorite/packages/node-csv-npm/Dsyko/meteor-node-csv/01be0e3e834a4f033121cb3fcc92c2697741170d/.build/npm/node_modules/csv/lib/to.js:274:14)
W2036-20:56:29.967(1)? (STDERR)     at EventEmitter.emit (events.js:95:17)
W2036-20:56:29.971(1)? (STDERR)     at null.<anonymous> (/home/russell/.meteorite/packages/node-csv-npm/Dsyko/meteor-node-csv/01be0e3e834a4f033121cb3fcc92c2697741170d/.build/npm/node_modules/csv/lib/index.js:214:17)
W2036-20:56:29.972(1)? (STDERR)     at EventEmitter.emit (events.js:92:17)
W2036-20:56:29.975(1)? (STDERR)     at Transformer.end (/home/russell/.meteorite/packages/node-csv-npm/Dsyko/meteor-node-csv/01be0e3e834a4f033121cb3fcc92c2697741170d/.build/npm/node_modules/csv/lib/transformer.js:241:17)

回答1:

I wanted to find a solution that didn't load the entire CSV file into memory, for use with large datasets. Here's my solution that uses Meteor.bindEnvironment, along with node-csv, to parse a CSV file into a Meteor Collection.

Thanks to the folks on #meteor for the help.

var csv = Meteor.require('CSV'); 
var fs = Meteor.require('fs');
var path = Npm.require('path');

function loadData() {
  var basepath = path.resolve('.').split('.meteor')[0];

  csv().from.stream(
    fs.createReadStream(basepath+'server/data/enron_data.csv'),
      {'escape': '\\'})
    .on('record', Meteor.bindEnvironment(function(row, index) {
      Emails.insert({
        'sender_id': row[0]
        // etc.
        })
      }, function(error) {
          console.log('Error in bindEnvironment:', error);
      }
    ))
    .on('error', function(err) {
      console.log('Error reading CSV:', err);
    })
    .on('end', function(count) {
      console.log(count, 'records read');
    });

}

回答2:

So it turns out because CSV() uses a callback and runs Asynchronous code, I needed to use a 'Future'. For more explaination see http://gist.io/3443021

here's my working code:

Meteor.methods({
     'uploadFile': function (file) {

      Future = Npm.require('fibers/future');

      console.log(file.name+'\'+file.type+'\'+file.size);                       

      file.save('/home/russell/tmp',{});
      var buffer = new Buffer(file.data);


      // Set up the Future
      var fut = new Future(); 

      // Convert buffer (a CSV file) to an array
      CSV().from(
                   buffer.toString(),
                   {comment: '#', delimiter: ',', quote: ''} 
                )
           .to.array( function(data){

                                       var newRecords=[];

                                       for(var row=0; row<data.length; row++) {
                                         console.log(data[row]);
                                         newRecord = {
                                                       'firstname': data[row][0],
                                                       'lastname': data[row][1],
                                                       'email': data[row][2],
                                                       'emailshort': data[row][3],
                                                       'emailmain': data[row][4],
                                                       'domain': data[row][5]
                                                     };

                                         //console.log(newRecord);
                                         newRecords.push(newRecord);
                                  }

                                  // at the end of the CSV callback
                                  // return newRecords via the Future
                                  fut['return'](newRecords);
    } );


    // Wait for the results of the conversion
    results = fut.wait();
    console.log('results================');
    console.log(results);

    // now insert the new records from the file into our collectiion
    if (results.length) {
        for(i in results) {
            reas.insert(results[i]);
        }
    }

    console.log('reas now looks like =====================');
    console.log(reas.find({}).fetch());

} // uploadFile

});