CODEWITHSUNDEEP
javascriptasp.net-mvccsvknockout.js
user3619254
user3619254

Reputation: 59

how to handles empty lines when reading CSV files in javascript

I'm using KnockoutJS in my MVc Project to load a csv file & provide a simple validation for import mechanism

The workflow is as follows:

this is an example of csv Lines :

Account_id,External_id,Amount,Transaction_Date,Office_date,Bank,Receipt_nbr,Type,statement,receipt,

0559394,,5,6/20/2017,7/7/2017,Cash,1729002903597,PNL,172900290,3597,

0099952,,19,6/20/2017,7/7/2017,Cash,1729002903653,PNL,172900290,3653,

,,,,,,,,,,

,,,,,,,,,,

,,,,,,,,,,

Here my code used to Upload file :

$('#lnkUpload').click(function () {
    var FileToRead = document.getElementById('UserFile');
    if (FileToRead.files.length > 0) {
        var reader = new FileReader();
        // assign function to the OnLoad event of the FileReader  
        // non synchronous event, therefore assign to other method  
        reader.onload = Load_CSVData;
        // call the reader to capture the file  
        reader.readAsText(FileToRead.files.item(0));
    }
    self.userModel.removeAll();

});

 function Load_CSVData(e) {
    self.userModel.removeAll();


    CSVLines = e.target.result.split(/\r\n|\n/);
    $CSVLines = CSVLines.slice(1);
    $.each($CSVLines, function (i, item) {

        var element = item.split(","); // builds an array from comma delimited items  
        var LAccount_id = (element[0] == undefined) ? "" : element[0].trim();
        var LExternal_id = (element[1] == undefined) ? "" : element[1].trim();
        var LAmount = (element[2] == undefined) ? "" : element[2].trim();
        var LTransaction_date = (element[3] == undefined) ? "" : element[3].trim();
        var LOffice_date = (element[4] == undefined) ? "" : element[4].trim();
        var LBank = (element[5] == undefined) ? "" : element[5].trim();
        var LReceipt_nbr = (element[6] == undefined) ? "" : element[6].trim();
        var LType = (element[7] == undefined) ? "" : element[7].trim();
        var Lstatement = (element[8] == undefined) ? "" : element[8].trim();
        var Lreceipt = (element[9] == undefined) ? "" : element[9].trim();






        self.userModel.push(new userModel()
            .Account_id(LAccount_id)
            .External_id(LExternal_id)
            .Amount(LAmount)
            .Transaction_date(LTransaction_date)
            .Office_date(LOffice_date)
            .Bank(LBank)
            .Receipt_nbr(LReceipt_nbr)
            .Type(LType)
            .statement(Lstatement)
            .receipt(Lreceipt))

    });

}

how can i update the code to Ignore and skip over empty Lines or treat them as the end of the input file or any other suggestion

Upvotes: 2

Views: 5695

Answers (2)

meesern
meesern

Reputation: 2656

This will detect a line that consists only of commas and/or white space (so will match "\n", "", ",,,,,", ", , , , ," etc. but not ",,,,1,,,,,"

if (item.match(/^[,\s]*$/)) { continue; }

Upvotes: 1

ChannelJuanNews
ChannelJuanNews

Reputation: 425

You can detect if the current line is a newline character. 

if(item == "\n") { continue; }

EDIT:

As matt pointed out, if the whitespace is made up of spaces the above solution will not work. Simply erase any spaces to detect if the row is made up of spaces. 

if(item == "\n" || item.trim().length == 0) { continue; }

Upvotes: 5

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