/// <inheritdoc />
public override Task <ProviderCultureResult> DetermineProviderCultureResult(IOwinContext httpContext)
{
if (httpContext == null)
{
throw new ArgumentNullException(nameof(httpContext));
}
var acceptLanguageHeader = httpContext.Request.Headers.GetCommaSeparatedValues("Accept-Language");
if (acceptLanguageHeader == null || acceptLanguageHeader.Count == 0)
{
return(NullProviderCultureResult);
}
var languages = StringWithQualityHeaderValue.ParseList(acceptLanguageHeader);
if (MaximumAcceptLanguageHeaderValuesToTry > 0)
{
// We take only the first configured number of languages from the header and then order those that we
// attempt to parse as a CultureInfo to mitigate potentially spinning CPU on lots of parse attempts.
languages = languages.Take(MaximumAcceptLanguageHeaderValuesToTry).ToList();
}
var orderedLanguages = languages.OrderByDescending(h => h, StringWithQualityHeaderValueComparer.QualityComparer)
.Select(x => x.Value).ToList();
if (orderedLanguages.Count > 0)
{
return(Task.FromResult(new ProviderCultureResult(orderedLanguages)));
}
return(NullProviderCultureResult);
}
public void ParseList_SetOfValidValueStrings_ParsedCorrectly()
{
var inputs = new[]
{
"",
"text1",
"text2,",
"textA,textB",
"text3;q=0.5",
"text4;q=0.5,",
" text5 ; q = 0.50 ",
"\r\n text6 ; q = 0.05 ",
"text7,text8;q=0.5",
" text9 , text10 ; q = 0.5 ",
};
IList <StringWithQualityHeaderValue> results = StringWithQualityHeaderValue.ParseList(inputs);
var expectedResults = new[]
{
new StringWithQualityHeaderValue("text1"),
new StringWithQualityHeaderValue("text2"),
new StringWithQualityHeaderValue("textA"),
new StringWithQualityHeaderValue("textB"),
new StringWithQualityHeaderValue("text3", 0.5),
new StringWithQualityHeaderValue("text4", 0.5),
new StringWithQualityHeaderValue("text5", 0.5),
new StringWithQualityHeaderValue("text6", 0.05),
new StringWithQualityHeaderValue("text7"),
new StringWithQualityHeaderValue("text8", 0.5),
new StringWithQualityHeaderValue("text9"),
new StringWithQualityHeaderValue("text10", 0.5),
}.ToList();
Assert.Equal(expectedResults, results);
}
public void SortStringWithQualityHeaderValuesByQFactor_SortsCorrectly(IEnumerable <string> unsorted, IEnumerable <string> expectedSorted)
{
var unsortedValues = StringWithQualityHeaderValue.ParseList(unsorted.ToList());
var expectedSortedValues = StringWithQualityHeaderValue.ParseList(expectedSorted.ToList());
var actualSorted = unsortedValues.OrderByDescending(k => k, StringWithQualityHeaderValueComparer.QualityComparer).ToList();
Assert.True(expectedSortedValues.SequenceEqual(actualSorted));
}
private static string Negotiate(IList <string> acceptedValueStrings, IList <string> supportedValueStrings)
{
var acceptedValues = new List <StringWithQualityHeaderValue>(StringWithQualityHeaderValue.ParseList(acceptedValueStrings));
acceptedValues.Sort(StringWithQualityHeaderValueComparer.QualityComparer);
foreach (var acceptedValue in acceptedValues)
{
var match = supportedValueStrings.FirstOrDefault(v => acceptedValue.Value == v);
if (match != null)
{
return(match);
}
}
return(null);
}
public void ParseList_WithSomeInvalidValues_IgnoresInvalidValues()
{
var inputs = new[]
{
"",
"text1",
"text 1",
"text2",
"\"text 2\",",
"text3;q=0.5",
"text4;q=0.5, extra stuff",
" text5 ; q = 0.50 ",
"\r\n text6 ; q = 0.05 ",
"text7,text8;q=0.5",
" text9 , text10 ; q = 0.5 ",
};
var results = StringWithQualityHeaderValue.ParseList(inputs);
var expectedResults = new[]
{
new StringWithQualityHeaderValue("text1"),
new StringWithQualityHeaderValue("1"),
new StringWithQualityHeaderValue("text2"),
new StringWithQualityHeaderValue("text3", 0.5),
new StringWithQualityHeaderValue("text4", 0.5),
new StringWithQualityHeaderValue("stuff"),
new StringWithQualityHeaderValue("text5", 0.5),
new StringWithQualityHeaderValue("text6", 0.05),
new StringWithQualityHeaderValue("text7"),
new StringWithQualityHeaderValue("text8", 0.5),
new StringWithQualityHeaderValue("text9"),
new StringWithQualityHeaderValue("text10", 0.5),
}.ToList();
Assert.Equal(expectedResults, results);
}
