Can I write a file to a folder on a server machine from a Web API app running on it?

Question

I have this code in my Web API app to write to a CSV file:

private void SaveToCSV(InventoryItem invItem, string dbContext)
{
    string csvHeader = "id,pack_size,description,vendor_id,department,subdepartment,unit_cost,unit_list,open_qty,UPC_code,UPC_pack_size,vendor_item,crv_id";

    int dbContextAsInt = 0;
    int.TryParse(dbContext, out dbContextAsInt);
    string csvFilename = string.Format("Platypus{0}.csv", dbContextAsInt);

    string csv = string.Format("{0},{1},{2},{3},{4},{5},{6},{7},{8},{9},{10},{11},{12}", invItem.ID,
        invItem.pksize, invItem.Description, invItem.vendor_id, invItem.dept, invItem.subdept, invItem.UnitCost,
        invItem.UnitList, invItem.OpenQty, invItem.UPC, invItem.upc_pack_size, invItem.vendor_item, invItem.crv_id);

    string existingContents;
    using (StreamReader sr = new StreamReader(csvFilename))
    {
        existingContents = sr.ReadToEnd();
    }

    using (StreamWriter writetext = File.AppendText(csvFilename))
    {
        if (!existingContents.Contains(csvHeader))
        {
            writetext.WriteLine(csvHeader);
        }
        writetext.WriteLine(csv);
    }
}

On the dev machine, the csv file is saved to "C:\Program Files (x86)\IIS Express" by default. In preparation for when it is deployed to its final resting/working place, what do I need to do to get the file to save, e.g., to the server's "Platypi" folder - anything special? Do I have to specifically set certain folder persimmons to allow writing to "Platypi."

Is it simply a matter of changing this line:

string csvFilename = string.Format("Platypus{0}.csv", dbContextAsInt);

...to this:

string csvFilename = string.Format(@"\Platypi\Platypus{0}.csv", dbContextAsInt);

?

Patrick Hofman · Accepted Answer · 2014-02-10T20:34:55.187

19

In the case of the IIS folder the application has rights to write in there. I suggest to write files to the App_Data folder.

When you want to save files outside the IIS application folder you have to give the service account of the IIS application pool (I think it by default is NETWORKSERVICE) the appropriate rights on that folder.

As requested by B. Clay Shannon my implementation:

string fullSavePath = HttpContext.Current.Server.MapPath(string.Format("~/App_Data/Platypus{0}.csv", dbContextAsInt));

edited Feb 10 '14 at 20:34

answered Feb 07 '14 at 23:13

Patrick Hofman

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Would I write to the AppData folder via Environment.SpecialFolder.ApplicationData? – B. Clay Shannon-B. Crow Raven Feb 08 '14 at 00:11
The following line simply returns the string "ApplicationPath": string pathOfMostResistence = Environment.SpecialFolder.ApplicationData.ToString(); – B. Clay Shannon-B. Crow Raven Feb 08 '14 at 00:22
2

Simply use `Server.MapPath("~/App_Data/...")`. This returns the app_data folder. The `~` means application root folder. – Patrick Hofman Feb 08 '14 at 09:11
1

Do you need more help? – Patrick Hofman Feb 10 '14 at 14:09
Trying to see just what this would return, I added this code: string bla = Server.MapPath("~/App_Data/"); ...and "Server" is not recognized ("Cannot resolve symbol 'Server'") – B. Clay Shannon-B. Crow Raven Feb 10 '14 at 16:40
Try `HttpContext.Current.Server.MapPath` – Patrick Hofman Feb 10 '14 at 16:46
I am referencing System.Web, I do have a "using System.Web" and even prepending HttpServerUtility fails; in fact, Intellisense only shows UrlTokenEnclode and UrlTokenDecode as legitimate selections after "HttpServerUtility." – B. Clay Shannon-B. Crow Raven Feb 10 '14 at 16:49
Don't use `HttpServerUtility` but `HttpContext` – Patrick Hofman Feb 10 '14 at 16:51
OK, that works fine; add it as an answer, and I'll mark it as such. I'm going to add my own answer, with the exact code I used, too. Or, edit your existing answer, I should say, with this additional info. – B. Clay Shannon-B. Crow Raven Feb 10 '14 at 17:05
@B.ClayShannon: I took your code and updated it a little to my liking. – Patrick Hofman Feb 10 '14 at 20:35

B. Clay Shannon-B. Crow Raven · Answer 2 · 2014-02-10T17:14:51.313

4

Thanks to Patrick Hofman; this is the exact code I am using, and it is saved to the project's App_Data folder:

public static string appDataFolder = HttpContext.Current.Server.MapPath("~/App_Data/");
. . .
string csvFilename = string.Format("Platypus{0}.csv", dbContextAsInt);
string fullSavePath = string.Format("{0}{1}", appDataFolder, csvFilename);

edited Feb 10 '14 at 17:14

answered Feb 10 '14 at 17:08

B. Clay Shannon-B. Crow Raven

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Can I write a file to a folder on a server machine from a Web API app running on it?

2 Answers2

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