/// <summary>
/// Asynchronously creates a <see cref="JToken"/> from a <see cref="JsonReader"/>.
/// </summary>
/// <param name="reader">An <see cref="JsonReader"/> positioned at the token to read into this <see cref="JToken"/>.</param>
/// <param name="settings">The <see cref="JsonLoadSettings"/> used to load the JSON.
/// If this is <c>null</c>, default load settings will be used.</param>
/// <param name="cancellationToken">The token to monitor for cancellation requests. The default value is <see cref="CancellationToken.None"/>.</param>
/// <returns>
/// A <see cref="Task{TResult}"/> that represents the asynchronous creation. The
/// <see cref="Task{TResult}.Result"/> property returns a <see cref="JToken"/> that contains
/// the token and its descendant tokens
/// that were read from the reader. The runtime type of the token is determined
/// by the token type of the first token encountered in the reader.
/// </returns>
public static async Task <JToken> ReadFromAsync(JsonReader reader, JsonLoadSettings settings, CancellationToken cancellationToken = default(CancellationToken))
{
ValidationUtils.ArgumentNotNull(reader, nameof(reader));
if (reader.TokenType == JsonToken.None)
{
if (!await(settings != null && settings.CommentHandling == CommentHandling.Ignore ? reader.ReadAndMoveToContentAsync(cancellationToken) : reader.ReadAsync(cancellationToken)).ConfigureAwait(false))
{
throw JsonReaderException.Create(reader, "Error reading JToken from JsonReader.");
}
}
IJsonLineInfo lineInfo = reader as IJsonLineInfo;
switch (reader.TokenType)
{
case JsonToken.StartObject:
return(await JObject.LoadAsync(reader, settings, cancellationToken).ConfigureAwait(false));
case JsonToken.StartArray:
return(await JArray.LoadAsync(reader, settings, cancellationToken).ConfigureAwait(false));
case JsonToken.StartConstructor:
return(await JConstructor.LoadAsync(reader, settings, cancellationToken).ConfigureAwait(false));
case JsonToken.PropertyName:
return(await JProperty.LoadAsync(reader, settings, cancellationToken).ConfigureAwait(false));
case JsonToken.String:
case JsonToken.Integer:
case JsonToken.Float:
case JsonToken.Date:
case JsonToken.Boolean:
case JsonToken.Bytes:
JValue v = new JValue(reader.Value);
v.SetLineInfo(lineInfo, settings);
return(v);
case JsonToken.Comment:
v = JValue.CreateComment(reader.Value.ToString());
v.SetLineInfo(lineInfo, settings);
return(v);
case JsonToken.Null:
v = JValue.CreateNull();
v.SetLineInfo(lineInfo, settings);
return(v);
case JsonToken.Undefined:
v = JValue.CreateUndefined();
v.SetLineInfo(lineInfo, settings);
return(v);
default:
throw JsonReaderException.Create(reader, "Error reading JToken from JsonReader. Unexpected token: {0}".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
}
}
internal void ReadContentFrom(JsonReader r, JsonLoadSettings settings)
{
ValidationUtils.ArgumentNotNull(r, nameof(r));
IJsonLineInfo lineInfo = r as IJsonLineInfo;
JContainer parent = this;
do
{
if ((parent as JProperty)?.Value != null)
{
if (parent == this)
{
return;
}
parent = parent.Parent;
}
switch (r.TokenType)
{
case JsonToken.None:
// new reader. move to actual content
break;
case JsonToken.StartArray:
JArray a = new JArray();
a.SetLineInfo(lineInfo, settings);
parent.Add(a);
parent = a;
break;
case JsonToken.EndArray:
if (parent == this)
{
return;
}
parent = parent.Parent;
break;
case JsonToken.StartObject:
JObject o = new JObject();
o.SetLineInfo(lineInfo, settings);
parent.Add(o);
parent = o;
break;
case JsonToken.EndObject:
if (parent == this)
{
return;
}
parent = parent.Parent;
break;
case JsonToken.StartConstructor:
JConstructor constructor = new JConstructor(r.Value.ToString());
constructor.SetLineInfo(lineInfo, settings);
parent.Add(constructor);
parent = constructor;
break;
case JsonToken.EndConstructor:
if (parent == this)
{
return;
}
parent = parent.Parent;
break;
case JsonToken.String:
case JsonToken.Integer:
case JsonToken.Float:
case JsonToken.Date:
case JsonToken.Boolean:
case JsonToken.Bytes:
JValue v = new JValue(r.Value);
v.SetLineInfo(lineInfo, settings);
parent.Add(v);
break;
case JsonToken.Comment:
if (settings != null && settings.CommentHandling == CommentHandling.Load)
{
v = JValue.CreateComment(r.Value.ToString());
v.SetLineInfo(lineInfo, settings);
parent.Add(v);
}
break;
case JsonToken.Null:
v = JValue.CreateNull();
v.SetLineInfo(lineInfo, settings);
parent.Add(v);
break;
case JsonToken.Undefined:
v = JValue.CreateUndefined();
v.SetLineInfo(lineInfo, settings);
parent.Add(v);
break;
case JsonToken.PropertyName:
string propertyName = r.Value.ToString();
JProperty property = new JProperty(propertyName);
property.SetLineInfo(lineInfo, settings);
JObject parentObject = (JObject)parent;
// handle multiple properties with the same name in JSON
JProperty existingPropertyWithName = parentObject.Property(propertyName);
if (existingPropertyWithName == null)
{
parent.Add(property);
}
else
{
existingPropertyWithName.Replace(property);
}
parent = property;
break;
default:
throw new InvalidOperationException("The JsonReader should not be on a token of type {0}.".FormatWith(CultureInfo.InvariantCulture, r.TokenType));
}
} while (r.Read());
}