How do I download a CSV file to a string from an https URL?

Question

The code that I have listed here works when I ReadAllText from a local file. What I need to be able to do is replace the path "C:\LocalFiles\myFile.csv" with "https://mySite.blah/myFile.csv".

I have tried several methods, but can't seem to be able to get the csv file loaded into a string variable. If I could just do that, then the code would work for me.

var csv = System.IO.File.ReadAllText(@"C:\LocalFiles\myFile.csv");

StringBuilder sb = new StringBuilder();
using (var p = ChoCSVReader.LoadText(csv).WithFirstLineHeader())
{
    p.Configuration.NullValue = null;

    if (p.Configuration.CSVRecordFieldConfigurations.IsNullOrEmpty())
    {
        p.Configuration.NullValue = null;
    }

    // ChoIgnoreFieldValueMode.DBNull = ChoIgnoreFieldValueMode.Empty();
    using (var w = new ChoJSONWriter(sb))
        w.Write(p);
}
string fullJson = sb.ToString();

If I simply replace the path, I get an error message that says that the path is invalid.

Answer 1

You need to get the string using a web request:

string urlAddress = "https://mySite.blah/myFile.csv";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urlAddress);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();

if (response.StatusCode == HttpStatusCode.OK)
{
    Stream receiveStream = response.GetResponseStream();
    StreamReader readStream = null;
    if (response.CharacterSet == null)
    {
        readStream = new StreamReader(receiveStream);
    }
    else
    {
        readStream = new StreamReader(receiveStream,
        Encoding.GetEncoding(response.CharacterSet));
    }

    string data = readStream.ReadToEnd();
    response.Close();
    readStream.Close();
}

or using a Webclient:

WebClient wc = new WebClient();
string data = wc.DownloadString("https://mySite.blah/myFile.csv");

Then pass data into your reader instead of using the System.IO.File.ReadAllText(@"C:\LocalFiles\myFile.csv");

Both of the above examples assume that the file is publicly accessible at that url without authentication or specific header values.

Answer 2

Replace this line

var csv = System.IO.File.ReadAllText(@"C:\LocalFiles\myFile.csv");

with

string result = client.GetStringAsync("https://mySite.blah/myFile.csv").Result;

or

var textFromFile = (new WebClient()).DownloadString("https://mySite.blah/myFile.csv");

There are many other ways to do it as well. Just google it.