WebApi-CSVFormatter

Adds CSV formatted response support in ASP.NET Web API

Usage of partial response

Register the CsvFormatter in Register (in WebApiConfig.cs):

config.Formatters.Add(new CsvFormatter());

or to specify a Func

config.Formatters.Add(new CsvFormatter { Selector = func  } );

Now if an Accept header with a value of text/csv is supplied the response will be automatically formatted as CSV before being returned

Complex object support

CsvReponse accepts a Func to control which object is used as the source when a complex object is used, see examples below.

Column Headers

You can now control the column headers by using the new CsvColumn attribute, see examples below.

Delimiters

Well it's a comma (,) as in Comma Separated Values :-)

Reserved characters (commas, double quotes, newlines)

If these characters are encountered they will be wrapped within double quotes ("")

fields parameter

The fields parameter controls which fields are returned in the response.

The following rules explain the supported syntax for the fields parameter value:

• fields=id,name to select multiple fields
• fields=* to select all fields

If fields is omitted all fields are returned

Examples

Given an object like this

class Product {
  public int Id {get; set;}
  public string Name {get; set;}
  public string Barcode {get; set;}
  public decimal Cost {get; set;}
}

Will give the following output...

https://myapi.mycompany.com/products

"Id", "Name", "Barcode", "Cost"
1,Banana,08765412,0.45
2,Apple,256895,0.75
3,Orange,895698,0.60

https://myapi.mycompany.com/products?fields=id,name

"Id", "Name"
1,Banana
2,Apple
3,Orange

https://myapi.mycompany.com/products?fields=id,name,cost

"Id", "Name", "Cost"
1,Banana,0.45
2,Apple,0.75
3,Orange,0.60

Given an object like this

class Customer {
  public int Id {get; set;}
  public string Name {get; set;}
  public List<Address> Addresses {get; set;}
}

class Address {
  public string Street {get; set;}
  public string Town {get; set;}
  public string County {get; set;}
  public string Postcode {get; set;}
}

and a Func like this

Func<object, HttpRequestMessage, object> func = (o, h) => ((Customer)o).Addresses;

https://myapi.mycompany.com/customers

"Street", "Town", "County", "Postcode"
Davigdor Road,Hove,East Sussex,BN31RE

If we modify the object to include the CsvColumn attribute

class Product {
  [CsvColumn(Name="Product Id")]
  public int Id {get; set;}
  
  [CsvColumn(Name="Product Name")]
  public string Name {get; set;}
  
  public string Barcode {get; set;}
  
  [CsvColumn(Name="RRP")]
  public decimal Cost {get; set;}
}

Will give the following output...

https://myapi.mycompany.com/products

"Product Id", "Product Name", "Barcode", "RRP"
1,Banana,08765412,0.45
2,Apple,256895,0.75
3,Orange,895698,0.60