/// <summary>
/// StartAsync
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public async Task <ImageResult> StartAsync(ProcessingPipelineContext context)
{
using (FilterContext filterContext = CreateFilterContext(context))
{
//execute filters
while (filterContext.ProcessingContext.UrlFilters.Count > 0)
{
string filter = filterContext.ProcessingContext.UrlFilters.Peek();
//find and execute filter
IFilterAction foundFilter = FilterActions.FirstOrDefault(x => x.TryExecute(filter, filterContext));
if (foundFilter != null)
{
Logger.LogTrace("Filter executed: " + filter);
filterContext.ProcessingContext.UrlFilters.Dequeue();
}
else
{
Logger.LogTrace($"filter was not found: {filter}");
throw new Exception($"Filter was not found: {filter}");
//return false;
}
//stop processing?
if (filterContext.Result != null)
{
return(filterContext.Result);
}
}
return(await filterContext.BuildResultAsync());
}
}
/// <summary>
/// AddFilter
/// </summary>
/// <typeparam name="TFilter"></typeparam>
public void AddFilter <TFilter>()
where TFilter : TFilterBase
{
MethodInfo[] methods = typeof(TFilter)
.GetMethods()
.Where(x => x.IsPublic)
.Where(x => x.GetCustomAttribute <FilterAttribute>() != null)
.ToArray();
foreach (MethodInfo method in methods)
{
ParameterInfo[] parameters = method.GetParameters();
Type[] integerTypes = new Type[] { typeof(byte), typeof(short), typeof(int), typeof(long) };
Type[] floatingNumberTypes = new Type[] { typeof(float), typeof(double), typeof(decimal) };
ParameterItem CreateParameter(ParameterInfo pi, string pattern)
{
return(new ParameterItem()
{
Name = pi.Name, Pattern = $@"(?<{pi.Name}>{pattern})"
});
}
List <ParameterItem> pp = new List <ParameterItem>();
for (int i = 0; i < parameters.Length; i++)
{
ParameterInfo currentParameter = parameters[i];
if (integerTypes.Any(x => x == currentParameter.ParameterType))
{
pp.Add(CreateParameter(currentParameter, @"-?\d+"));
}
else if (floatingNumberTypes.Any(x => x == currentParameter.ParameterType))
{
pp.Add(CreateParameter(currentParameter, @"-?\d+\.\d+"));
}
else if (currentParameter.ParameterType == typeof(bool))
{
pp.Add(CreateParameter(parameters[i], "True|False"));
}
else if (currentParameter.ParameterType == typeof(string))
{
ParameterItem p = CreateParameter(parameters[i], "[^']*");
p.Pattern = $"'{p.Pattern}'";
pp.Add(p);
}
else if (currentParameter.ParameterType.IsEnum)
{
//@"[a-z]{1}[a-z0-9]*"
string[] enumValues = Enum.GetNames(parameters[i].ParameterType)
.Select(x => x.ToLower())
.ToArray();
pp.Add(CreateParameter(parameters[i], string.Join("|", enumValues)));
}
else
{
throw new Exception("parameter type is not supported: " + parameters[i].ParameterType.Name);
}
}
StringBuilder builder = new StringBuilder("^");
//function begin
builder.Append($@"{method.Name.ToLowerInvariant()}\(");
bool optionalParmeterCall = parameters.All(x => (x.DefaultValue is DBNull) == false);
if (optionalParmeterCall)
{
//add optional parameters
builder.Append($"(,|{string.Join("|", pp.Select(x => $"({x.Name}={x.Pattern})").ToArray())})*");
}
else
{
//add all parameters
builder.Append(string.Join(",", pp.Select(x => x.Pattern).ToArray()));
}
//function end
builder.Append(@"\)$");
IFilterAction filterAction = CreateFilterAction <TFilter>(new Regex(builder.ToString(), RegexOptions.Compiled), method);
FilterActions.Add(filterAction);
}
}
