/// <summary>
/// Append default values required by OData to specified HTTP header.
///
/// When header name is ODataConstants.ContentTypeHeader, if header value is application/json
/// append the following default values for 4.0:
/// odata.metadata=minimal
/// odata.streaming=true
/// IEEE754Compatible=false
/// append the following default values for 4.01:
/// metadata=minimal
/// streaming=true
/// IEEE754Compatible=false
/// </summary>
/// <param name="headerName">The name of the header to append default values.</param>
/// <param name="headerValue">The original header value string.</param>
/// <param name="version">The ODataVersion for which to create the default header value</param>
/// <returns>The header value string with appended default values.</returns>
public static string AppendDefaultHeaderValue(string headerName, string headerValue, ODataVersion version)
{
if (string.CompareOrdinal(headerName, ODataConstants.ContentTypeHeader) != 0)
{
return(headerValue);
}
if (headerValue == null)
{
return(null);
}
var mediaTypeList = HttpUtils.MediaTypesFromString(headerValue);
var mediaType = mediaTypeList.Single().Key;
var encoding = HttpUtils.GetEncodingFromCharsetName(mediaTypeList.Single().Value);
if (string.CompareOrdinal(mediaType.FullTypeName, MimeConstants.MimeApplicationJson) != 0)
{
return(headerValue);
}
var extendedParameters = new List <KeyValuePair <string, string> >();
var extendedMediaType = new ODataMediaType(mediaType.Type, mediaType.SubType, extendedParameters);
var hasMetadata = false;
var hasStreaming = false;
var hasIeee754Compatible = false;
if (mediaType.Parameters != null)
{
foreach (var parameter in mediaType.Parameters)
{
extendedParameters.Add(parameter);
if (HttpUtils.IsMetadataParameter(parameter.Key))
{
hasMetadata = true;
}
if (HttpUtils.IsStreamingParameter(parameter.Key))
{
hasStreaming = true;
}
if (string.Compare(parameter.Key, MimeConstants.MimeIeee754CompatibleParameterName, StringComparison.OrdinalIgnoreCase) == 0)
{
hasIeee754Compatible = true;
}
}
}
if (!hasMetadata)
{
extendedParameters.Add(new KeyValuePair <string, string>(
version < ODataVersion.V401 ? MimeConstants.MimeMetadataParameterName : MimeConstants.MimeShortMetadataParameterName,
MimeConstants.MimeMetadataParameterValueMinimal));
}
if (!hasStreaming)
{
extendedParameters.Add(new KeyValuePair <string, string>(
version < ODataVersion.V401 ? MimeConstants.MimeStreamingParameterName : MimeConstants.MimeShortStreamingParameterName,
MimeConstants.MimeParameterValueTrue));
}
if (!hasIeee754Compatible)
{
extendedParameters.Add(new KeyValuePair <string, string>(
MimeConstants.MimeIeee754CompatibleParameterName,
MimeConstants.MimeParameterValueFalse));
}
return(extendedMediaType.ToText(encoding));
}
