I am using Google.protobuf.BoolValue type in my .proto file, but when I compile the proto file, I see the variable type as FieldCodec in autogenerated field, instead of BoolValue type of well known types.
Because of this, when I use this variable in my c# file, I can use it as bool type and it is accepting values without error. But when assigning the value using new BoolValue{}, Im getting error.
this is my proto file:
syntax = "proto3";
import "google/protobuf/wrappers.proto";
option csharp_namespace = "cSharpSample";
message StudentMessage {
string Name = 1;
google.protobuf.BoolValue IsGood = 2;
bool Isbool = 3;
}
Autogenerated file:
/// <summary>Field number for the "IsGood" field.</summary>
public const int IsGoodFieldNumber = 2;
private static readonly pb::FieldCodec<bool?> _single_isGood_codec = pb::FieldCodec.ForStructWrapper<bool>(18);
private bool? isGood_;
[global::System.Diagnostics.DebuggerNonUserCodeAttribute]
[global::System.CodeDom.Compiler.GeneratedCode("protoc", null)]
public bool? IsGood {
get { return isGood_; }
set {
isGood_ = value;
}
}
in program.cs file:
StudentMessage msg = new StudentMessage();
msg.Isbool = true;
msg.IsGood= new BoolValue { Value = true };
I get this error:
error CS0029: Cannot implicitly convert type 'Google.Protobuf.WellKnownTypes.BoolValue' to 'bool?'
The Variable IsGood should work like BoolValue, but it is working like bool type.
The generated tooling special-cases this scenario, and uses bool? instead of the wrapper message type. This provided both a more idiomatic .NET API (since the semantics of BoolValue and bool? are similar), and avoids some allocations. So : just use the bool? and forget about BoolValue entirely!
FieldCodec here is static and is just part of the machinery; you don't need to interact with that at all.
Related
I have installed and used Microsoft.Web.RedisSessionStateProvider for a while and after looking at OutputCaching I thought of installing Microsoft.Web.RedisOutputCacheProvider as well but they both have Microsoft.Web.Redis.ISerializer interface which breaks my JsonCacheSerializer as it uses the ISerializer interface.
I am getting an error in VS 2017, which reads ...
"The type 'ISerializer' exists in both Microsoft.Web.RedisOutputCacheProvider and Microsoft.Web.RedisSessionStateProvider"
The JsonCacheSerializer code I use for SessionState is :
public class JsonCacheSerializer : Microsoft.Web.Redis.ISerializer
{
private static readonly JsonSerializerSettings Settings = new JsonSerializerSettings()
{
TypeNameHandling = TypeNameHandling.All,
ReferenceLoopHandling = ReferenceLoopHandling.Serialize,
PreserveReferencesHandling = PreserveReferencesHandling.Objects,
Error = (serializer, err) => {
err.ErrorContext.Handled = true;
}
};
public byte[] Serialize(object data)
{
return Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(data, Settings));
}
public object Deserialize(byte[] data)
{
return data == null ? null : JsonConvert.DeserializeObject(Encoding.UTF8.GetString(data), Settings);
}
}
Does this mean one has to use one or the other, not both?
You may use extern alias feature of C#
https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/extern-alias
Visual Studio example:
1) right click Microsoft.Web.RedisOutputCacheProvider and put following into Aliases field:
global,redisoutputcacheprovider
2) right click Microsoft.Web.RedisSessionStateProvider and put following into Aliases field:
global,redissessionstateprovider
then on top of your code file add:
extern alias redissessionstateprovider;
extern alias redisoutputcacheprovider;
and finally declare your class as:
public class JsonCacheSessionStateSerializer : redissessionstateprovider::Microsoft.Web.Redis.ISerializer
Just came across the latest build of Mono.CSharp and love the promise it offers.
Was able to get the following all worked out:
namespace XAct.Spikes.Duo
{
class Program
{
static void Main(string[] args)
{
CompilerSettings compilerSettings = new CompilerSettings();
compilerSettings.LoadDefaultReferences = true;
Report report = new Report(new Mono.CSharp.ConsoleReportPrinter());
Mono.CSharp.Evaluator e;
e= new Evaluator(compilerSettings, report);
//IMPORTANT:This has to be put before you include references to any assemblies
//our you;ll get a stream of errors:
e.Run("using System;");
//IMPORTANT:You have to reference the assemblies your code references...
//...including this one:
e.Run("using XAct.Spikes.Duo;");
//Go crazy -- although that takes time:
//foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
//{
// e.ReferenceAssembly(assembly);
//}
//More appropriate in most cases:
e.ReferenceAssembly((typeof(A).Assembly));
//Exception due to no semicolon
//e.Run("var a = 1+3");
//Doesn't set anything:
//e.Run("a = 1+3;");
//Works:
//e.ReferenceAssembly(typeof(A).Assembly);
e.Run("var a = 1+3;");
e.Run("A x = new A{Name=\"Joe\"};");
var a = e.Evaluate("a;");
var x = e.Evaluate("x;");
//Not extremely useful:
string check = e.GetVars();
//Note that you have to type it:
Console.WriteLine(((A) x).Name);
e = new Evaluator(compilerSettings, report);
var b = e.Evaluate("a;");
}
}
public class A
{
public string Name { get; set; }
}
}
And that was fun...can create a variable in the script's scope, and export the value.
There's just one last thing to figure out... how can I get a value in (eg, a domain entity that I want to apply a Rule script on), without using a static (am thinking of using this in a web app)?
I've seen the use compiled delegates -- but that was for the previous version of Mono.CSharp, and it doesn't seem to work any longer.
Anybody have a suggestion on how to do this with the current version?
Thanks very much.
References:
* Injecting a variable into the Mono.CSharp.Evaluator (runtime compiling a LINQ query from string)
* http://naveensrinivasan.com/tag/mono/
I know it's almost 9 years later, but I think I found a viable solution to inject local variables. It is using a static variable but can still be used by multiple evaluators without collision.
You can use a static Dictionary<string, object> which holds the reference to be injected. Let's say we are doing all this from within our class CsharpConsole:
public class CsharpConsole {
public static Dictionary<string, object> InjectionRepository {get; set; } = new Dictionary<string, object>();
}
The idea is to temporarily place the value in there with a GUID as key so there won't be any conflict between multiple evaluator instances. To inject do this:
public void InjectLocal(string name, object value, string type=null) {
var id = Guid.NewGuid().ToString();
InjectionRepository[id] = value;
type = type ?? value.GetType().FullName;
// note for generic or nested types value.GetType().FullName won't return a compilable type string, so you have to set the type parameter manually
var success = _evaluator.Run($"var {name} = ({type})MyNamespace.CsharpConsole.InjectionRepository[\"{id}\"];");
// clean it up to avoid memory leak
InjectionRepository.Remove(id);
}
Also for accessing local variables there is a workaround using Reflection so you can have a nice [] accessor with get and set:
public object this[string variable]
{
get
{
FieldInfo fieldInfo = typeof(Evaluator).GetField("fields", BindingFlags.NonPublic | BindingFlags.Instance);
if (fieldInfo != null)
{
var fields = fieldInfo.GetValue(_evaluator) as Dictionary<string, Tuple<FieldSpec, FieldInfo>>;
if (fields != null)
{
if (fields.TryGetValue(variable, out var tuple) && tuple != null)
{
var value = tuple.Item2.GetValue(_evaluator);
return value;
}
}
}
return null;
}
set
{
InjectLocal(variable, value);
}
}
Using this trick, you can even inject delegates and functions that your evaluated code can call from within the script. For instance, I inject a print function which my code can call to ouput something to the gui console window:
public delegate void PrintFunc(params object[] o);
public void puts(params object[] o)
{
// call the OnPrint event to redirect the output to gui console
if (OnPrint!=null)
OnPrint(string.Join("", o.Select(x => (x ?? "null").ToString() + "\n").ToArray()));
}
This puts function can now be easily injected like this:
InjectLocal("puts", (PrintFunc)puts, "CsInterpreter2.PrintFunc");
And just be called from within your scripts:
puts(new object[] { "hello", "world!" });
Note, there is also a native function print but it directly writes to STDOUT and redirecting individual output from multiple console windows is not possible.
Trying to serialize a union-like data-type. There is an enum field indicating the type of data stored in the union, and a variety of possible field types.
The desired result is DataContractSerializer produced XML which contains just the enum, and the relevant field.
Possible solutions, none of which have been attempted yet, are:
Use a custom serializer and mark the union properties with a custom attribute, similar to this question. The custom serializer would strip out the members not required.
Use ISerializationSurrogate and serialize a different object which just contains the relevant data.
Don't use separate fields in the union, use one object field (this could be used as part of the implementation of the ISerializationSurrogate approach).
Other... ?
For example:
[DataContract]
public class WCFTestUnion
{
public enum EUnionType
{
[EnumMember]
Bool,
[EnumMember]
String,
[EnumMember]
Dictionary,
[EnumMember]
Invalid
};
EUnionType unionType = EUnionType.Invalid;
bool boolValue = true;
string stringValue = "Hello";
IDictionary<object, object> dictionaryValue = null;
// Could use custom attribute here ?
[DataMember]
public bool BoolValue
{
get { return this.boolValue; }
set { this.boolValue = value; }
}
// Could use custom attribute here ?
[DataMember]
public string StringValue
{
get { return this.stringValue; }
set { this.stringValue = value; }
}
// Could use custom attribute here ?
[DataMember]
public IDictionary<object, object> DictionaryValue
{
get { return this.dictionaryValue; }
set { this.dictionaryValue = value; }
}
[DataMember]
public EUnionType UnionType
{
get { return this.unionType; }
set { this.unionType = value; }
}
} // Ends class WCFTestUnion
Test
class TestSerializeUnion
{
internal static void Test()
{
Console.WriteLine("===TestSerializeUnion.Test()===");
WCFTestUnion u = new WCFTestUnion();
u.UnionType = WCFTestUnion.EUnionType.Dictionary;
u.DictionaryValue = new Dictionary<object, object>();
u.DictionaryValue[1] = "one";
u.DictionaryValue["two"] = 2;
System.Runtime.Serialization.DataContractSerializer serialize = new System.Runtime.Serialization.DataContractSerializer(typeof(WCFTestUnion));
System.IO.Stream stream = new System.IO.MemoryStream();
serialize.WriteObject(stream, u);
stream.Seek(0, System.IO.SeekOrigin.Begin);
byte[] buffer = new byte[stream.Length];
int length = checked((int)stream.Length);
int read = stream.Read(buffer, 0, length);
while (read < stream.Length)
{
read += stream.Read(buffer, 0, length - read);
}
string xml = Encoding.Default.GetString(buffer);
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
doc.LoadXml(xml);
System.Xml.XmlTextWriter xmlwriter = new System.Xml.XmlTextWriter(Console.Out);
xmlwriter.Formatting = System.Xml.Formatting.Indented;
doc.WriteContentTo(xmlwriter);
xmlwriter.Flush();
Console.WriteLine();
}
} // Ends class TestSerializeUnion
Output:
<WCFTestUnion xmlns="http://schemas.datacontract.org/2004/07/WCFTestServiceContracts" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<BoolValue>true</BoolValue>
<DictionaryValue xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
<a:KeyValueOfanyTypeanyType>
<a:Key i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">1</a:Key>
<a:Value i:type="b:string" xmlns:b="http://www.w3.org/2001/XMLSchema">one</a:Value>
</a:KeyValueOfanyTypeanyType>
<a:KeyValueOfanyTypeanyType>
<a:Key i:type="b:string" xmlns:b="http://www.w3.org/2001/XMLSchema">two</a:Key>
<a:Value i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">2</a:Value>
</a:KeyValueOfanyTypeanyType>
</DictionaryValue>
<StringValue>Hello </StringValue>
<UnionType>Dictionary</UnionType>
</WCFTestUnion>
Desired Output (only field being used is serialized, along with enum):
<WCFTestUnion xmlns="http://schemas.datacontract.org/2004/07/WCFTestServiceContracts" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<DictionaryValue xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
<a:KeyValueOfanyTypeanyType>
<a:Key i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">1</a:Key>
<a:Value i:type="b:string" xmlns:b="http://www.w3.org/2001/XMLSchema">one</a:Value>
</a:KeyValueOfanyTypeanyType>
<a:KeyValueOfanyTypeanyType>
<a:Key i:type="b:string" xmlns:b="http://www.w3.org/2001/XMLSchema">two</a:Key>
<a:Value i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">2</a:Value>
</a:KeyValueOfanyTypeanyType>
</DictionaryValue>
<UnionType>Dictionary</UnionType>
</WCFTestUnion>
You do have several options here. What you use depends on the complexity of this scenario (where else you have to do something like this, how often and in what ways you have to serialize this data, performance, etc.) Take a look at these options, ask away if you have more questions, but mostly, I recommend you just play and experiment with multiple strategies from the list below before picking one or a hybrid solution.
Use a data contract resolver. Provides a mechanism for dynamically mapping types to and from wire representations during serialization and deserialization, giving you flexibility to support far more types than you can out-of-the-box.
Use IObjectReference. You can have a class which implements and returns a reference to a different object after it has been deserialized.
Use a data contract surrogate. This is different from the serialization surrogates you're referring to, but also similar. I think these might work out nicely for you
I have the following code with a simple class and a method for writing and then reading:
ObjectMapper mapper = new ObjectMapper();
try{
DataStore testOut = new DataStore();
DataStore.Checklist ch1 = testOut.addChecklist();
ch1.SetTitle("Checklist1");
String output = mapper.writeValueAsString(testOut);
JsonNode rootNode = mapper.readValue(output, JsonNode.class);
Map<String,Object> userData = mapper.readValue(output, Map.class);
}
public class DataStore {
public static class Checklist
{
public Checklist()
{
}
private String _title;
public String GetTitle()
{
return _title;
}
public void SetTitle(String title)
{
_title = title;
}
}
//Checklists
private Vector<Checklist> _checklists = new Vector<Checklist>();
public Checklist addChecklist()
{
Checklist ch = new Checklist();
ch.SetTitle("New Checklist");
_checklists.add(ch);
return ch;
}
public Vector<Checklist> getChecklists()
{
return _checklists;
}
public void setChecklists(Vector<Checklist> checklists)
{
_checklists = checklists;
}
}
The line:
String output = mapper.writeValueAsString(testOut);
causes an exception that has had me baffled for hours and about to abandon using this at all.
Any hints are appreciated.
Here is the exception:
No serializer found for class DataStore$Checklist and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: DataStore["checklists"]->java.util.Vector[0])
There are multiple ways to do it, but I will start with what you are doing wrong: your naming of getter and setter method is wrong -- in Java one uses "camel-case", so you should be using "getTitle". Because of this, properties are not found.
Besides renaming methods to use Java-style names, there are alternatives:
You can use annotation JsonProperty("title") for GetTitle(), so that property is recognized
If you don't want the wrapper object, you could alternatively just add #JsonValue for GetTitle(), in which case value used for the whole object would be return value of that method.
The answer seems to be: You can't do that with Json. I've seen comments in the Gson tutorial as well, that state that some serialization just doesn't work. I downloaded XStream and spat it out with XML in a few minutes of work and a lot less construction around what I really wanted to persist. In the process, I was able to delete a lot of code.
I'm using a HeaderColumnNameMappingStrategy to map a csv file with a header into a JavaBean. String values parse fine but any "true" or "false" value in csv doesn't map to JavaBean and I get the following exception from the PropertyDescriptor:
java.lang.IllegalArgumentException: argument type mismatch
The code where it occurs is in CsvToBean, line 64:
protected T processLine(MappingStrategy<T> mapper, String[] line) throws
IllegalAccessException, InvocationTargetException, InstantiationException, IntrospectionException {
T bean = mapper.createBean();
for(int col = 0; col < line.length; col++) {
String value = line[col];
PropertyDescriptor prop = mapper.findDescriptor(col);
if (null != prop) {
Object obj = convertValue(value, prop);
// this is where exception is thrown for a "true" value in csv
prop.getWriteMethod().invoke(bean, new Object[] {obj});
}
}
return bean;
}
protected PropertyEditor getPropertyEditor(PropertyDescriptor desc) throws
InstantiationException, IllegalAccessException {
Class<?> cls = desc.getPropertyEditorClass();
if (null != cls) return (PropertyEditor) cls.newInstance();
return getPropertyEditorValue(desc.getPropertyType());
}
I can confirm (via debugger) that the setter method id correctly retrieved at this point.
The problem occurs in desc.getPropertyEditorClass() since it returns null. I assumed primitive types and its wrappers are supported. Are they not?
I've run into this same issue. The cleanest way is probably to override getPropertyEditor like pritam did above and return a custom PropertyEditor for your particular object. The quick and dirty way would be to override convertValue in anonymous class form, like this:
CsvToBean<MyClass> csvToBean = new CsvToBean<MyClass>(){
#Override
protected Object convertValue(String value, PropertyDescriptor prop) throws InstantiationException,IllegalAccessException {
if (prop.getName().equals("myWhatever")) {
// return an custom object based on the incoming value
return new MyWhatever((String)value);
}
return super.convertValue(value, prop);
}
};
This is working fine for me with OpenCSV 2.3. Good luck!
I resolved this by extending CsvToBean and adding my own PropertyEditors. Turns out opencsv just supports primitive types and no wrappers.
Pritam's answer is great and this is a sample for dealing with datetime format.
PropertyEditorManager.registerEditor(java.util.Date.class, DateEditor.class);
You should write your own editor class like this:
public class DateEditor extends PropertyEditorSupport{
public static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
#Override
public void setAsText(String text){
setValue(sdf.parse(text));}
}