Retail_manager/RMDataManager/Areas/HelpPage/SampleGeneration/HelpPageSampleGenerator.cs
2022-06-30 21:37:20 +02:00

444 lines
20 KiB
C#

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Net.Http.Headers;
using System.Web.Http.Description;
using System.Xml.Linq;
using Newtonsoft.Json;
namespace RMDataManager.Areas.HelpPage
{
/// <summary>
/// This class will generate the samples for the help page.
/// </summary>
public class HelpPageSampleGenerator
{
/// <summary>
/// Initializes a new instance of the <see cref="HelpPageSampleGenerator"/> class.
/// </summary>
public HelpPageSampleGenerator()
{
ActualHttpMessageTypes = new Dictionary<HelpPageSampleKey, Type>();
ActionSamples = new Dictionary<HelpPageSampleKey, object>();
SampleObjects = new Dictionary<Type, object>();
SampleObjectFactories = new List<Func<HelpPageSampleGenerator, Type, object>>
{
DefaultSampleObjectFactory,
};
}
/// <summary>
/// Gets CLR types that are used as the content of <see cref="HttpRequestMessage"/> or <see cref="HttpResponseMessage"/>.
/// </summary>
public IDictionary<HelpPageSampleKey, Type> ActualHttpMessageTypes { get; internal set; }
/// <summary>
/// Gets the objects that are used directly as samples for certain actions.
/// </summary>
public IDictionary<HelpPageSampleKey, object> ActionSamples { get; internal set; }
/// <summary>
/// Gets the objects that are serialized as samples by the supported formatters.
/// </summary>
public IDictionary<Type, object> SampleObjects { get; internal set; }
/// <summary>
/// Gets factories for the objects that the supported formatters will serialize as samples. Processed in order,
/// stopping when the factory successfully returns a non-<see langref="null"/> object.
/// </summary>
/// <remarks>
/// Collection includes just <see cref="ObjectGenerator.GenerateObject(Type)"/> initially. Use
/// <code>SampleObjectFactories.Insert(0, func)</code> to provide an override and
/// <code>SampleObjectFactories.Add(func)</code> to provide a fallback.</remarks>
[SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures",
Justification = "This is an appropriate nesting of generic types")]
public IList<Func<HelpPageSampleGenerator, Type, object>> SampleObjectFactories { get; private set; }
/// <summary>
/// Gets the request body samples for a given <see cref="ApiDescription"/>.
/// </summary>
/// <param name="api">The <see cref="ApiDescription"/>.</param>
/// <returns>The samples keyed by media type.</returns>
public IDictionary<MediaTypeHeaderValue, object> GetSampleRequests(ApiDescription api)
{
return GetSample(api, SampleDirection.Request);
}
/// <summary>
/// Gets the response body samples for a given <see cref="ApiDescription"/>.
/// </summary>
/// <param name="api">The <see cref="ApiDescription"/>.</param>
/// <returns>The samples keyed by media type.</returns>
public IDictionary<MediaTypeHeaderValue, object> GetSampleResponses(ApiDescription api)
{
return GetSample(api, SampleDirection.Response);
}
/// <summary>
/// Gets the request or response body samples.
/// </summary>
/// <param name="api">The <see cref="ApiDescription"/>.</param>
/// <param name="sampleDirection">The value indicating whether the sample is for a request or for a response.</param>
/// <returns>The samples keyed by media type.</returns>
public virtual IDictionary<MediaTypeHeaderValue, object> GetSample(ApiDescription api, SampleDirection sampleDirection)
{
if (api == null)
{
throw new ArgumentNullException("api");
}
string controllerName = api.ActionDescriptor.ControllerDescriptor.ControllerName;
string actionName = api.ActionDescriptor.ActionName;
IEnumerable<string> parameterNames = api.ParameterDescriptions.Select(p => p.Name);
Collection<MediaTypeFormatter> formatters;
Type type = ResolveType(api, controllerName, actionName, parameterNames, sampleDirection, out formatters);
var samples = new Dictionary<MediaTypeHeaderValue, object>();
// Use the samples provided directly for actions
var actionSamples = GetAllActionSamples(controllerName, actionName, parameterNames, sampleDirection);
foreach (var actionSample in actionSamples)
{
samples.Add(actionSample.Key.MediaType, WrapSampleIfString(actionSample.Value));
}
// Do the sample generation based on formatters only if an action doesn't return an HttpResponseMessage.
// Here we cannot rely on formatters because we don't know what's in the HttpResponseMessage, it might not even use formatters.
if (type != null && !typeof(HttpResponseMessage).IsAssignableFrom(type))
{
object sampleObject = GetSampleObject(type);
foreach (var formatter in formatters)
{
foreach (MediaTypeHeaderValue mediaType in formatter.SupportedMediaTypes)
{
if (!samples.ContainsKey(mediaType))
{
object sample = GetActionSample(controllerName, actionName, parameterNames, type, formatter, mediaType, sampleDirection);
// If no sample found, try generate sample using formatter and sample object
if (sample == null && sampleObject != null)
{
sample = WriteSampleObjectUsingFormatter(formatter, sampleObject, type, mediaType);
}
samples.Add(mediaType, WrapSampleIfString(sample));
}
}
}
}
return samples;
}
/// <summary>
/// Search for samples that are provided directly through <see cref="ActionSamples"/>.
/// </summary>
/// <param name="controllerName">Name of the controller.</param>
/// <param name="actionName">Name of the action.</param>
/// <param name="parameterNames">The parameter names.</param>
/// <param name="type">The CLR type.</param>
/// <param name="formatter">The formatter.</param>
/// <param name="mediaType">The media type.</param>
/// <param name="sampleDirection">The value indicating whether the sample is for a request or for a response.</param>
/// <returns>The sample that matches the parameters.</returns>
public virtual object GetActionSample(string controllerName, string actionName, IEnumerable<string> parameterNames, Type type, MediaTypeFormatter formatter, MediaTypeHeaderValue mediaType, SampleDirection sampleDirection)
{
object sample;
// First, try to get the sample provided for the specified mediaType, sampleDirection, controllerName, actionName and parameterNames.
// If not found, try to get the sample provided for the specified mediaType, sampleDirection, controllerName and actionName regardless of the parameterNames.
// If still not found, try to get the sample provided for the specified mediaType and type.
// Finally, try to get the sample provided for the specified mediaType.
if (ActionSamples.TryGetValue(new HelpPageSampleKey(mediaType, sampleDirection, controllerName, actionName, parameterNames), out sample) ||
ActionSamples.TryGetValue(new HelpPageSampleKey(mediaType, sampleDirection, controllerName, actionName, new[] { "*" }), out sample) ||
ActionSamples.TryGetValue(new HelpPageSampleKey(mediaType, type), out sample) ||
ActionSamples.TryGetValue(new HelpPageSampleKey(mediaType), out sample))
{
return sample;
}
return null;
}
/// <summary>
/// Gets the sample object that will be serialized by the formatters.
/// First, it will look at the <see cref="SampleObjects"/>. If no sample object is found, it will try to create
/// one using <see cref="DefaultSampleObjectFactory"/> (which wraps an <see cref="ObjectGenerator"/>) and other
/// factories in <see cref="SampleObjectFactories"/>.
/// </summary>
/// <param name="type">The type.</param>
/// <returns>The sample object.</returns>
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes",
Justification = "Even if all items in SampleObjectFactories throw, problem will be visible as missing sample.")]
public virtual object GetSampleObject(Type type)
{
object sampleObject;
if (!SampleObjects.TryGetValue(type, out sampleObject))
{
// No specific object available, try our factories.
foreach (Func<HelpPageSampleGenerator, Type, object> factory in SampleObjectFactories)
{
if (factory == null)
{
continue;
}
try
{
sampleObject = factory(this, type);
if (sampleObject != null)
{
break;
}
}
catch
{
// Ignore any problems encountered in the factory; go on to the next one (if any).
}
}
}
return sampleObject;
}
/// <summary>
/// Resolves the actual type of <see cref="System.Net.Http.ObjectContent{T}"/> passed to the <see cref="System.Net.Http.HttpRequestMessage"/> in an action.
/// </summary>
/// <param name="api">The <see cref="ApiDescription"/>.</param>
/// <returns>The type.</returns>
public virtual Type ResolveHttpRequestMessageType(ApiDescription api)
{
string controllerName = api.ActionDescriptor.ControllerDescriptor.ControllerName;
string actionName = api.ActionDescriptor.ActionName;
IEnumerable<string> parameterNames = api.ParameterDescriptions.Select(p => p.Name);
Collection<MediaTypeFormatter> formatters;
return ResolveType(api, controllerName, actionName, parameterNames, SampleDirection.Request, out formatters);
}
/// <summary>
/// Resolves the type of the action parameter or return value when <see cref="HttpRequestMessage"/> or <see cref="HttpResponseMessage"/> is used.
/// </summary>
/// <param name="api">The <see cref="ApiDescription"/>.</param>
/// <param name="controllerName">Name of the controller.</param>
/// <param name="actionName">Name of the action.</param>
/// <param name="parameterNames">The parameter names.</param>
/// <param name="sampleDirection">The value indicating whether the sample is for a request or a response.</param>
/// <param name="formatters">The formatters.</param>
[SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", Justification = "This is only used in advanced scenarios.")]
public virtual Type ResolveType(ApiDescription api, string controllerName, string actionName, IEnumerable<string> parameterNames, SampleDirection sampleDirection, out Collection<MediaTypeFormatter> formatters)
{
if (!Enum.IsDefined(typeof(SampleDirection), sampleDirection))
{
throw new InvalidEnumArgumentException("sampleDirection", (int)sampleDirection, typeof(SampleDirection));
}
if (api == null)
{
throw new ArgumentNullException("api");
}
Type type;
if (ActualHttpMessageTypes.TryGetValue(new HelpPageSampleKey(sampleDirection, controllerName, actionName, parameterNames), out type) ||
ActualHttpMessageTypes.TryGetValue(new HelpPageSampleKey(sampleDirection, controllerName, actionName, new[] { "*" }), out type))
{
// Re-compute the supported formatters based on type
Collection<MediaTypeFormatter> newFormatters = new Collection<MediaTypeFormatter>();
foreach (var formatter in api.ActionDescriptor.Configuration.Formatters)
{
if (IsFormatSupported(sampleDirection, formatter, type))
{
newFormatters.Add(formatter);
}
}
formatters = newFormatters;
}
else
{
switch (sampleDirection)
{
case SampleDirection.Request:
ApiParameterDescription requestBodyParameter = api.ParameterDescriptions.FirstOrDefault(p => p.Source == ApiParameterSource.FromBody);
type = requestBodyParameter == null ? null : requestBodyParameter.ParameterDescriptor.ParameterType;
formatters = api.SupportedRequestBodyFormatters;
break;
case SampleDirection.Response:
default:
type = api.ResponseDescription.ResponseType ?? api.ResponseDescription.DeclaredType;
formatters = api.SupportedResponseFormatters;
break;
}
}
return type;
}
/// <summary>
/// Writes the sample object using formatter.
/// </summary>
/// <param name="formatter">The formatter.</param>
/// <param name="value">The value.</param>
/// <param name="type">The type.</param>
/// <param name="mediaType">Type of the media.</param>
/// <returns></returns>
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "The exception is recorded as InvalidSample.")]
public virtual object WriteSampleObjectUsingFormatter(MediaTypeFormatter formatter, object value, Type type, MediaTypeHeaderValue mediaType)
{
if (formatter == null)
{
throw new ArgumentNullException("formatter");
}
if (mediaType == null)
{
throw new ArgumentNullException("mediaType");
}
object sample = String.Empty;
MemoryStream ms = null;
HttpContent content = null;
try
{
if (formatter.CanWriteType(type))
{
ms = new MemoryStream();
content = new ObjectContent(type, value, formatter, mediaType);
formatter.WriteToStreamAsync(type, value, ms, content, null).Wait();
ms.Position = 0;
StreamReader reader = new StreamReader(ms);
string serializedSampleString = reader.ReadToEnd();
if (mediaType.MediaType.ToUpperInvariant().Contains("XML"))
{
serializedSampleString = TryFormatXml(serializedSampleString);
}
else if (mediaType.MediaType.ToUpperInvariant().Contains("JSON"))
{
serializedSampleString = TryFormatJson(serializedSampleString);
}
sample = new TextSample(serializedSampleString);
}
else
{
sample = new InvalidSample(String.Format(
CultureInfo.CurrentCulture,
"Failed to generate the sample for media type '{0}'. Cannot use formatter '{1}' to write type '{2}'.",
mediaType,
formatter.GetType().Name,
type.Name));
}
}
catch (Exception e)
{
sample = new InvalidSample(String.Format(
CultureInfo.CurrentCulture,
"An exception has occurred while using the formatter '{0}' to generate sample for media type '{1}'. Exception message: {2}",
formatter.GetType().Name,
mediaType.MediaType,
UnwrapException(e).Message));
}
finally
{
if (ms != null)
{
ms.Dispose();
}
if (content != null)
{
content.Dispose();
}
}
return sample;
}
internal static Exception UnwrapException(Exception exception)
{
AggregateException aggregateException = exception as AggregateException;
if (aggregateException != null)
{
return aggregateException.Flatten().InnerException;
}
return exception;
}
// Default factory for sample objects
private static object DefaultSampleObjectFactory(HelpPageSampleGenerator sampleGenerator, Type type)
{
// Try to create a default sample object
ObjectGenerator objectGenerator = new ObjectGenerator();
return objectGenerator.GenerateObject(type);
}
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Handling the failure by returning the original string.")]
private static string TryFormatJson(string str)
{
try
{
object parsedJson = JsonConvert.DeserializeObject(str);
return JsonConvert.SerializeObject(parsedJson, Formatting.Indented);
}
catch
{
// can't parse JSON, return the original string
return str;
}
}
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "Handling the failure by returning the original string.")]
private static string TryFormatXml(string str)
{
try
{
XDocument xml = XDocument.Parse(str);
return xml.ToString();
}
catch
{
// can't parse XML, return the original string
return str;
}
}
private static bool IsFormatSupported(SampleDirection sampleDirection, MediaTypeFormatter formatter, Type type)
{
switch (sampleDirection)
{
case SampleDirection.Request:
return formatter.CanReadType(type);
case SampleDirection.Response:
return formatter.CanWriteType(type);
}
return false;
}
private IEnumerable<KeyValuePair<HelpPageSampleKey, object>> GetAllActionSamples(string controllerName, string actionName, IEnumerable<string> parameterNames, SampleDirection sampleDirection)
{
HashSet<string> parameterNamesSet = new HashSet<string>(parameterNames, StringComparer.OrdinalIgnoreCase);
foreach (var sample in ActionSamples)
{
HelpPageSampleKey sampleKey = sample.Key;
if (String.Equals(controllerName, sampleKey.ControllerName, StringComparison.OrdinalIgnoreCase) &&
String.Equals(actionName, sampleKey.ActionName, StringComparison.OrdinalIgnoreCase) &&
(sampleKey.ParameterNames.SetEquals(new[] { "*" }) || parameterNamesSet.SetEquals(sampleKey.ParameterNames)) &&
sampleDirection == sampleKey.SampleDirection)
{
yield return sample;
}
}
}
private static object WrapSampleIfString(object sample)
{
string stringSample = sample as string;
if (stringSample != null)
{
return new TextSample(stringSample);
}
return sample;
}
}
}