Saving and Loading file definitions while using <generic> version of FileEngine - filehelpers

I've successfully use the SaveToXml and LoadFromXml methods on the ClassBuilder class to store and retrieve the file definitions while using the Standard version of the File Helper Engine.
However I'd really prefer to use the generic version of the File Helper Engine. In other words I'd like to instatiate the engine like so:
var eng = new DelimitedFileEngine<OutputClass>(params....);
OutputClass[] records = eng.ReadFile("Sample.csv");
So my results are strongly typed and not just an array of objects.
Does this save and load functionality exist for the generic file helper engine?

Sure, it works exactly as you'd expect.
[DelimitedRecord("|")]
public class OutputClass
{
public string First { get; set; }
public string Second { get; set; }
}
class Program
{
static void Main(string[] args)
{
var eng = new DelimitedFileEngine<OutputClass>();
// To read from a file use ReadFile()
//OutputClass[] records = eng.ReadFile("Sample.csv");
// Or to read from a string use ReadString()
OutputClass[] records = eng.ReadString("First|Second");
Debug.Assert(records.Length == 1);
Debug.Assert(records[0].First == "First");
Debug.Assert(records[0].Second == "Second");
Console.WriteLine("All OK");
Console.ReadKey();
}
}
Edit:
Based on your comment below, you want to map the results from your XML class to a concrete C# object. The easiest way is to use read into a DataTable and map the fields to the C# object.
var cb = new DelimitedClassBuilder(nameof(OutputClass), "|");
cb.AddField("First", typeof(string));
cb.AddField("Second", typeof(string));
var xmlString = cb.SaveToXmlString();
var outputClass = DelimitedClassBuilder.LoadFromXmlString(xmlString);
var eng = new FileHelperEngine(outputClass.CreateRecordClass());
OutputClass[] records = eng
.ReadStringAsDT("First|Second")
.Rows.OfType<DataRow>()
.Select(x => new OutputClass() {
First = x.Field<string>("First"),
Second = x.Field<string>("Second")
})
.ToArray();

Related

Web API Help pages - customizing Property documentation

I have my web api and I added the web api help pages to auto-generate my documentation. It's working great for methods where my parameters are listed out, but I have a method like this:
public SessionResult PostLogin(CreateSessionCommand request)
And, on my help page, it is only listing the command parameter in the properties section. However, in the sample request section, it lists out all of the properties of my CreateSessionCommand class.
Parameters
Name | Description | Additional information
request | No documentation available. | Define this parameter in the request body.
I would like it instead to list all of the properties in my CreateSessionCommand class. Is there an easy way to do this?
So, I managed to devise a workaround for this problem, in case anyone is interested.
In HelpPageConfigurationExtensions.cs I added the following extension method:
public static void AlterApiDescription(this ApiDescription apiDescription, HttpConfiguration config)
{
var docProvider = config.Services.GetDocumentationProvider();
var addParams = new List<ApiParameterDescription>();
var removeParams = new List<ApiParameterDescription>();
foreach (var param in apiDescription.ParameterDescriptions)
{
var type = param.ParameterDescriptor.ParameterType;
//string is some special case that is not a primitive type
//also, compare by full name because the type returned does not seem to match the types generated by typeof
bool isPrimitive = type.IsPrimitive || String.Compare(type.FullName, typeof(string).FullName) == 0;
if (!isPrimitive)
{
var properties = from p in param.ParameterDescriptor.ParameterType.GetProperties()
let s = p.SetMethod
where s.IsPublic
select p;
foreach (var property in properties)
{
var documentation = docProvider.GetDocumentation(new System.Web.Http.Controllers.ReflectedHttpParameterDescriptor()
{
ActionDescriptor = param.ParameterDescriptor.ActionDescriptor,
ParameterInfo = new CustomParameterInfo(property)
});
addParams.Add(new ApiParameterDescription()
{
Documentation = documentation,
Name = property.Name,
Source = ApiParameterSource.FromBody,
ParameterDescriptor = param.ParameterDescriptor
});
}
//since this is a complex type, select it to be removed from the api description
removeParams.Add(param);
}
}
//add in our new items
foreach (var item in addParams)
{
apiDescription.ParameterDescriptions.Add(item);
}
//remove the complex types
foreach (var item in removeParams)
{
apiDescription.ParameterDescriptions.Remove(item);
}
}
And here is the Parameter info instanced class I use
internal class CustomParameterInfo : ParameterInfo
{
public CustomParameterInfo(PropertyInfo prop)
{
base.NameImpl = prop.Name;
}
}
Then, we call the extension in another method inside the extensions class
public static HelpPageApiModel GetHelpPageApiModel(this HttpConfiguration config, string apiDescriptionId)
{
object model;
string modelId = ApiModelPrefix + apiDescriptionId;
if (!config.Properties.TryGetValue(modelId, out model))
{
Collection<ApiDescription> apiDescriptions = config.Services.GetApiExplorer().ApiDescriptions;
ApiDescription apiDescription = apiDescriptions.FirstOrDefault(api => String.Equals(api.GetFriendlyId(), apiDescriptionId, StringComparison.OrdinalIgnoreCase));
if (apiDescription != null)
{
apiDescription.AlterApiDescription(config);
HelpPageSampleGenerator sampleGenerator = config.GetHelpPageSampleGenerator();
model = GenerateApiModel(apiDescription, sampleGenerator);
config.Properties.TryAdd(modelId, model);
}
}
return (HelpPageApiModel)model;
}
The comments that are used for this must be added to the controller method and not the properties of the class object. This might be because my object is part of an outside library
this should go as an addition to #Josh answer. If you want not only to list properties from the model class, but also include documentation for each property, Areas/HelpPage/XmlDocumentationProvider.cs file should be modified as follows:
public virtual string GetDocumentation(HttpParameterDescriptor parameterDescriptor)
{
ReflectedHttpParameterDescriptor reflectedParameterDescriptor = parameterDescriptor as ReflectedHttpParameterDescriptor;
if (reflectedParameterDescriptor != null)
{
if (reflectedParameterDescriptor.ParameterInfo is CustomParameterInfo)
{
const string PropertyExpression = "/doc/members/member[#name='P:{0}']";
var pi = (CustomParameterInfo) reflectedParameterDescriptor.ParameterInfo;
string selectExpression = String.Format(CultureInfo.InvariantCulture, PropertyExpression, pi.Prop.DeclaringType.FullName + "." + pi.Prop.Name);
XPathNavigator methodNode = _documentNavigator.SelectSingleNode(selectExpression);
if (methodNode != null)
{
return methodNode.Value.Trim();
}
}
else
{
XPathNavigator methodNode = GetMethodNode(reflectedParameterDescriptor.ActionDescriptor);
if (methodNode != null)
{
string parameterName = reflectedParameterDescriptor.ParameterInfo.Name;
XPathNavigator parameterNode = methodNode.SelectSingleNode(String.Format(CultureInfo.InvariantCulture, ParameterExpression, parameterName));
if (parameterNode != null)
{
return parameterNode.Value.Trim();
}
}
}
}
return null;
}
and CustomParameterInfo class should keep property info as well:
internal class CustomParameterInfo : ParameterInfo
{
public PropertyInfo Prop { get; private set; }
public CustomParameterInfo(PropertyInfo prop)
{
Prop = prop;
base.NameImpl = prop.Name;
}
}
This is currently not supported out of the box. Following bug is kind of related to that:
http://aspnetwebstack.codeplex.com/workitem/877

How can I use MEF to manage interdependent modules?

I found this question difficult to express (particularly in title form), so please bear with me.
I have an application that I am continually modifying to do different things. It seems like MEF might be a good way to manage the different pieces of functionality. Broadly speaking, there are three sections of the application that form a pipeline of sorts:
Acquisition
Transformation
Expression
In it's simplest form, I can express each of these stages as an interface (IAcquisition etc). The problems start when I want to use acquisition components that provides richer data than standard. I want to design modules that use this richer data, but I can't rely on it being there.
I could, of course, add all of the data to the interface specification. I could deal with poorer data sources by throwing an exception or returning a null value. This seems a long way from ideal.
I'd prefer to do the MEF binding in three stages, such that modules are offered to the user only if they are compatible with those selected previously.
So my question: Can I specify metadata which restricts the set of available imports?
An example:
Acquision1 offers BasicData only
Acquision2 offers BasicData and AdvancedData
Transformation1 requires BasicData
Transformation2 requires BasicData and AdvancedData
Acquisition module is selected first.
If Acquisition1 is selected, don't offer Transformation 2, otherwise offer both.
Is this possible? If so, how?
Your question suggests a structure like this:
public class BasicData
{
public string Basic { get; set; } // example data
}
public class AdvancedData : BasicData
{
public string Advanced { get; set; } // example data
}
Now you have your acquisition, transformation and expression components. You want to be able to deal with different kinds of data, so they're generic:
public interface IAcquisition<out TDataKind>
{
TDataKind Acquire();
}
public interface ITransformation<TDataKind>
{
TDataKind Transform(TDataKind data);
}
public interface IExpression<in TDataKind>
{
void Express(TDataKind data);
}
And now you want to build a pipeline out of them that looks like this:
IExpression.Express(ITransformation.Transform(IAcquisition.Acquire));
So let's start building a pipeline builder:
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;
using System.ComponentModel.Composition.Primitives;
using System.Linq;
using System.Linq.Expressions;
// namespace ...
public static class PipelineBuidler
{
private static readonly string AcquisitionIdentity =
AttributedModelServices.GetTypeIdentity(typeof(IAcquisition<>));
private static readonly string TransformationIdentity =
AttributedModelServices.GetTypeIdentity(typeof(ITransformation<>));
private static readonly string ExpressionIdentity =
AttributedModelServices.GetTypeIdentity(typeof(IExpression<>));
public static Action BuildPipeline(ComposablePartCatalog catalog,
Func<IEnumerable<string>, int> acquisitionSelector,
Func<IEnumerable<string>, int> transformationSelector,
Func<IEnumerable<string>, int> expressionSelector)
{
var container = new CompositionContainer(catalog);
The class holds MEF type identities for your three contract interfaces. We'll need those later to identify the correct exports. Our BuildPipeline method returns an Action. That is going to be the pipeline, so we can just do pipeline(). It takes a ComposablePartCatalog and three Funcs (to select an export). That way, we can keep all the dirty work inside this class. Then we start by creating a CompositionContainer.
Now we have to build ImportDefinitions, first for the acquisition component:
var aImportDef = new ImportDefinition(def => (def.ContractName == AcquisitionIdentity), null, ImportCardinality.ZeroOrMore, true, false);
This ImportDefinition simply filters out all exports of the IAcquisition<> interface. Now we can give it to the container:
var aExports = container.GetExports(aImportDef).ToArray();
aExports now holds all IAcquisition<> exports in the catalog. So let's run the selector on this:
var selectedAExport = aExports[acquisitionSelector(aExports.Select(export => export.Metadata["Name"] as string))];
And there we have our acquisition component:
var acquisition = selectedAExport.Value;
var acquisitionDataKind = (Type)selectedAExport.Metadata["DataKind"];
Now we're going to do the same for the transformation and the expression components, but with one slight difference: The ImportDefinition is going to ensure that each component can handle the output of the previous component.
var tImportDef = new ImportDefinition(def => (def.ContractName == TransformationIdentity) && ((Type)def.Metadata["DataKind"]).IsAssignableFrom(acquisitionDataKind),
null, ImportCardinality.ZeroOrMore, true, false);
var tExports = container.GetExports(tImportDef).ToArray();
var selectedTExport = tExports[transformationSelector(tExports.Select(export => export.Metadata["Name"] as string))];
var transformation = selectedTExport.Value;
var transformationDataKind = (Type)selectedTExport.Metadata["DataKind"];
var eImportDef = new ImportDefinition(def => (def.ContractName == ExpressionIdentity) && ((Type)def.Metadata["DataKind"]).IsAssignableFrom(transformationDataKind),
null, ImportCardinality.ZeroOrMore, true, false);
var eExports = container.GetExports(eImportDef).ToArray();
var selectedEExport = eExports[expressionSelector(eExports.Select(export => export.Metadata["Name"] as string))];
var expression = selectedEExport.Value;
var expressionDataKind = (Type)selectedEExport.Metadata["DataKind"];
And now we can wire it all up in an expression tree:
var acquired = Expression.Call(Expression.Constant(acquisition), typeof(IAcquisition<>).MakeGenericType(acquisitionDataKind).GetMethod("Acquire"));
var transformed = Expression.Call(Expression.Constant(transformation), typeof(ITransformation<>).MakeGenericType(transformationDataKind).GetMethod("Transform"), acquired);
var expressed = Expression.Call(Expression.Constant(expression), typeof(IExpression<>).MakeGenericType(expressionDataKind).GetMethod("Express"), transformed);
return Expression.Lambda<Action>(expressed).Compile();
}
}
And that's it! A simple example application would look like this:
[Export(typeof(IAcquisition<>))]
[ExportMetadata("DataKind", typeof(BasicData))]
[ExportMetadata("Name", "Basic acquisition")]
public class Acquisition1 : IAcquisition<BasicData>
{
public BasicData Acquire()
{
return new BasicData { Basic = "Acquisition1" };
}
}
[Export(typeof(IAcquisition<>))]
[ExportMetadata("DataKind", typeof(AdvancedData))]
[ExportMetadata("Name", "Advanced acquisition")]
public class Acquisition2 : IAcquisition<AdvancedData>
{
public AdvancedData Acquire()
{
return new AdvancedData { Advanced = "Acquisition2A", Basic = "Acquisition2B" };
}
}
[Export(typeof(ITransformation<>))]
[ExportMetadata("DataKind", typeof(BasicData))]
[ExportMetadata("Name", "Basic transformation")]
public class Transformation1 : ITransformation<BasicData>
{
public BasicData Transform(BasicData data)
{
data.Basic += " - Transformed1";
return data;
}
}
[Export(typeof(ITransformation<>))]
[ExportMetadata("DataKind", typeof(AdvancedData))]
[ExportMetadata("Name", "Advanced transformation")]
public class Transformation2 : ITransformation<AdvancedData>
{
public AdvancedData Transform(AdvancedData data)
{
data.Basic += " - Transformed2";
data.Advanced += " - Transformed2";
return data;
}
}
[Export(typeof(IExpression<>))]
[ExportMetadata("DataKind", typeof(BasicData))]
[ExportMetadata("Name", "Basic expression")]
public class Expression1 : IExpression<BasicData>
{
public void Express(BasicData data)
{
Console.WriteLine("Expression1: {0}", data.Basic);
}
}
[Export(typeof(IExpression<>))]
[ExportMetadata("DataKind", typeof(AdvancedData))]
[ExportMetadata("Name", "Advanced expression")]
public class Expression2 : IExpression<AdvancedData>
{
public void Express(AdvancedData data)
{
Console.WriteLine("Expression2: ({0}) - ({1})", data.Basic, data.Advanced);
}
}
class Program
{
static void Main(string[] args)
{
var pipeline = PipelineBuidler.BuildPipeline(new AssemblyCatalog(typeof(Program).Assembly), StringSelector, StringSelector, StringSelector);
pipeline();
}
static int StringSelector(IEnumerable<string> strings)
{
int i = 0;
foreach (var item in strings)
Console.WriteLine("[{0}] {1}", i++, item);
return int.Parse(Console.ReadLine());
}
}

Mono.CSharp: how do I inject a value/entity *into* a script?

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.

Dynamic Anonymous type in Razor causes RuntimeBinderException

I'm getting the following error:
'object' does not contain a definition for 'RatingName'
When you look at the anonymous dynamic type, it clearly does have RatingName.
I realize I can do this with a Tuple, but I would like to understand why the error message occurs.
Anonymous types having internal properties is a poor .NET framework design decision, in my opinion.
Here is a quick and nice extension to fix this problem i.e. by converting the anonymous object into an ExpandoObject right away.
public static ExpandoObject ToExpando(this object anonymousObject)
{
IDictionary<string, object> anonymousDictionary = new RouteValueDictionary(anonymousObject);
IDictionary<string, object> expando = new ExpandoObject();
foreach (var item in anonymousDictionary)
expando.Add(item);
return (ExpandoObject)expando;
}
It's very easy to use:
return View("ViewName", someLinq.Select(new { x=1, y=2}.ToExpando());
Of course in your view:
#foreach (var item in Model) {
<div>x = #item.x, y = #item.y</div>
}
I found the answer in a related question. The answer is specified on David Ebbo's blog post Passing anonymous objects to MVC views and accessing them using dynamic
The reason for this is that the
anonymous type being passed in the
controller in internal, so it can only
be accessed from within the assembly
in which it’s declared. Since views
get compiled separately, the dynamic
binder complains that it can’t go over
that assembly boundary.
But if you think about it, this
restriction from the dynamic binder is
actually quite artificial, because if
you use private reflection, nothing is
stopping you from accessing those
internal members (yes, it even work in
Medium trust). So the default dynamic
binder is going out of its way to
enforce C# compilation rules (where
you can’t access internal members),
instead of letting you do what the CLR
runtime allows.
Using ToExpando method is the best solution.
Here is the version that doesn't require System.Web assembly:
public static ExpandoObject ToExpando(this object anonymousObject)
{
IDictionary<string, object> expando = new ExpandoObject();
foreach (PropertyDescriptor propertyDescriptor in TypeDescriptor.GetProperties(anonymousObject))
{
var obj = propertyDescriptor.GetValue(anonymousObject);
expando.Add(propertyDescriptor.Name, obj);
}
return (ExpandoObject)expando;
}
Instead of creating a model from an anonymous type and then trying to convert the anonymous object to an ExpandoObject like this ...
var model = new
{
Profile = profile,
Foo = foo
};
return View(model.ToExpando()); // not a framework method (see other answers)
You can just create the ExpandoObject directly:
dynamic model = new ExpandoObject();
model.Profile = profile;
model.Foo = foo;
return View(model);
Then in your view you set the model type as dynamic #model dynamic and you can access the properties directly :
#Model.Profile.Name
#Model.Foo
I'd normally recommend strongly typed view models for most views, but sometimes this flexibility is handy.
You can use the framework impromptu interface to wrap an anonymous type in an interface.
You'd just return an IEnumerable<IMadeUpInterface> and at the end of your Linq use .AllActLike<IMadeUpInterface>(); this works because it calls the anonymous property using the DLR with a context of the assembly that declared the anonymous type.
Wrote a console application and add Mono.Cecil as reference (you can now add it from NuGet), then write the piece of code:
static void Main(string[] args)
{
var asmFile = args[0];
Console.WriteLine("Making anonymous types public for '{0}'.", asmFile);
var asmDef = AssemblyDefinition.ReadAssembly(asmFile, new ReaderParameters
{
ReadSymbols = true
});
var anonymousTypes = asmDef.Modules
.SelectMany(m => m.Types)
.Where(t => t.Name.Contains("<>f__AnonymousType"));
foreach (var type in anonymousTypes)
{
type.IsPublic = true;
}
asmDef.Write(asmFile, new WriterParameters
{
WriteSymbols = true
});
}
The code above would get the assembly file from input args and use Mono.Cecil to change the accessibility from internal to public, and that would resolve the problem.
We can run the program in the Post Build event of the website. I wrote a blog post about this in Chinese but I believe you can just read the code and snapshots. :)
Based on the accepted answer, I have overridden in the controller to make it work in general and behind the scenes.
Here is the code:
protected override void OnResultExecuting(ResultExecutingContext filterContext)
{
base.OnResultExecuting(filterContext);
//This is needed to allow the anonymous type as they are intenal to the assembly, while razor compiles .cshtml files into a seperate assembly
if (ViewData != null && ViewData.Model != null && ViewData.Model.GetType().IsNotPublic)
{
try
{
IDictionary<string, object> expando = new ExpandoObject();
(new RouteValueDictionary(ViewData.Model)).ToList().ForEach(item => expando.Add(item));
ViewData.Model = expando;
}
catch
{
throw new Exception("The model provided is not 'public' and therefore not avaialable to the view, and there was no way of handing it over");
}
}
}
Now you can just pass an anonymous object as the model, and it will work as expected.
I'm going to do a little bit of stealing from https://stackoverflow.com/a/7478600/37055
If you install-package dynamitey you can do this:
return View(Build<ExpandoObject>.NewObject(RatingName: name, Comment: comment));
And the peasants rejoice.
The reason of RuntimeBinderException triggered, I think there have good answer in other posts. I just focus to explain how I actually make it work.
By refer to answer #DotNetWise and Binding views with Anonymous type collection in ASP.NET MVC,
Firstly, Create a static class for extension
public static class impFunctions
{
//converting the anonymous object into an ExpandoObject
public static ExpandoObject ToExpando(this object anonymousObject)
{
//IDictionary<string, object> anonymousDictionary = new RouteValueDictionary(anonymousObject);
IDictionary<string, object> anonymousDictionary = HtmlHelper.AnonymousObjectToHtmlAttributes(anonymousObject);
IDictionary<string, object> expando = new ExpandoObject();
foreach (var item in anonymousDictionary)
expando.Add(item);
return (ExpandoObject)expando;
}
}
In controller
public ActionResult VisitCount()
{
dynamic Visitor = db.Visitors
.GroupBy(p => p.NRIC)
.Select(g => new { nric = g.Key, count = g.Count()})
.OrderByDescending(g => g.count)
.AsEnumerable() //important to convert to Enumerable
.Select(c => c.ToExpando()); //convert to ExpandoObject
return View(Visitor);
}
In View, #model IEnumerable (dynamic, not a model class), this is very important as we are going to bind the anonymous type object.
#model IEnumerable<dynamic>
#*#foreach (dynamic item in Model)*#
#foreach (var item in Model)
{
<div>x=#item.nric, y=#item.count</div>
}
The type in foreach, I have no error either using var or dynamic.
By the way, create a new ViewModel that is matching the new fields also can be the way to pass the result to the view.
Now in recursive flavor
public static ExpandoObject ToExpando(this object obj)
{
IDictionary<string, object> expandoObject = new ExpandoObject();
new RouteValueDictionary(obj).ForEach(o => expandoObject.Add(o.Key, o.Value == null || new[]
{
typeof (Enum),
typeof (String),
typeof (Char),
typeof (Guid),
typeof (Boolean),
typeof (Byte),
typeof (Int16),
typeof (Int32),
typeof (Int64),
typeof (Single),
typeof (Double),
typeof (Decimal),
typeof (SByte),
typeof (UInt16),
typeof (UInt32),
typeof (UInt64),
typeof (DateTime),
typeof (DateTimeOffset),
typeof (TimeSpan),
}.Any(oo => oo.IsInstanceOfType(o.Value))
? o.Value
: o.Value.ToExpando()));
return (ExpandoObject) expandoObject;
}
Using the ExpandoObject Extension works but breaks when using nested anonymous objects.
Such as
var projectInfo = new {
Id = proj.Id,
UserName = user.Name
};
var workitem = WorkBL.Get(id);
return View(new
{
Project = projectInfo,
WorkItem = workitem
}.ToExpando());
To accomplish this I use this.
public static class RazorDynamicExtension
{
/// <summary>
/// Dynamic object that we'll utilize to return anonymous type parameters in Views
/// </summary>
public class RazorDynamicObject : DynamicObject
{
internal object Model { get; set; }
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (binder.Name.ToUpper() == "ANONVALUE")
{
result = Model;
return true;
}
else
{
PropertyInfo propInfo = Model.GetType().GetProperty(binder.Name);
if (propInfo == null)
{
throw new InvalidOperationException(binder.Name);
}
object returnObject = propInfo.GetValue(Model, null);
Type modelType = returnObject.GetType();
if (modelType != null
&& !modelType.IsPublic
&& modelType.BaseType == typeof(Object)
&& modelType.DeclaringType == null)
{
result = new RazorDynamicObject() { Model = returnObject };
}
else
{
result = returnObject;
}
return true;
}
}
}
public static RazorDynamicObject ToRazorDynamic(this object anonymousObject)
{
return new RazorDynamicObject() { Model = anonymousObject };
}
}
Usage in the controller is the same except you use ToRazorDynamic() instead of ToExpando().
In your view to get the entire anonymous object you just add ".AnonValue" to the end.
var project = #(Html.Raw(JsonConvert.SerializeObject(Model.Project.AnonValue)));
var projectName = #Model.Project.Name;
I tried the ExpandoObject but it didn't work with a nested anonymous complex type like this:
var model = new { value = 1, child = new { value = 2 } };
So my solution was to return a JObject to View model:
return View(JObject.FromObject(model));
and convert to dynamic in .cshtml:
#using Newtonsoft.Json.Linq;
#model JObject
#{
dynamic model = (dynamic)Model;
}
<span>Value of child is: #model.child.value</span>

Serialize a FeatureClass to XML in ESRI ArcGIS

How can I serialize an IFeatureClass object to XML?
There are some resources for using IXMLSerializer on other ArcObjects, but that won't work for IFeatureClass because it doesn't implement ISerializable.
I've actual found my own answer to this question. I'm posting this question and answer here for the benefit of others and for feedback/critique on my approach.
IFeatureClass cannot be serialized directly, but IRecordSet2 can be. So the first step is implementing a method to convert IFeatureClass to IRecordSet2:
private static IRecordSet2 ConvertToRecordset(IFeatureClass fc)
{
IRecordSet recSet = new RecordSetClass();
IRecordSetInit recSetInit = recSet as IRecordSetInit;
recSetInit.SetSourceTable(fc as ITable, null);
return (IRecordSet2) recSetInit;
}
Then it's easy to use IXMLSerializer to get XML:
public static XElement StoreAsXml(IFeatureClass fc)
{
// Can't serialize a feature class directly, so convert
// to recordset first.
IRecordSet2 recordset = ConvertToRecordset(fc);
IXMLSerializer xmlSer = new XMLSerializerClass();
string sXml = xmlSer.SaveToString(recordset, null, null);
return XElement.Parse(sXml);
}
However, when you convert to IRecordSet2, you lose the feature class name, so when writing to a file, I add an element to the XML to hold the feature class name:
public static void StoreToFile(IFeatureClass fc, string filePath)
{
XElement xdoc = StoreAsXml(fc);
XElement el = new XElement("FeatureClass", new XAttribute( "name", fc.AliasName ),
xdoc);
el.Save(filePath);
}
Now, just reverse the process to read the XML into a feature class. Remember that an element was added to store the feature class name:
public static IFeatureClass RetreiveFromFile(string filepath)
{
XElement xdoc = XElement.Load(filepath);
string sName = xdoc.FirstAttribute.Value;
XNode recordset = xdoc.FirstNode;
return RetreiveFromXml(recordset, sName);
}
Simple de-serialization using IXMLSerializer to get a IRecordSet2:
public static IFeatureClass RetreiveFromXml(XNode node, string sName)
{
IXMLSerializer xmlDeSer = new XMLSerializerClass();
IRecordSet2 recordset = (IRecordSet2)xmlDeSer.LoadFromString(node.ToString(), null, null);
return ConvertToFeatureClass(recordset, sName);
}
This was the tricky part. I'm open to suggestions on how to improve this ... covert the IRecordSet2 object into an IFeatureClass:
private static IFeatureClass ConvertToFeatureClass(IRecordSet2 rs, string sName)
{
IWorkspaceFactory pWSFact = new ShapefileWorkspaceFactory();
string sTempPath = Path.GetTempPath();
IFeatureWorkspace pFWS = (IFeatureWorkspace)pWSFact.OpenFromFile( sTempPath, 0);
// Will fail (COM E_FAIL) if the dataset already exists
DeleteExistingDataset(pFWS, sName);
IFeatureClass pFeatClass = null;
pFeatClass = pFWS.CreateFeatureClass(sName, rs.Fields, null, null, esriFeatureType.esriFTSimple,
"SHAPE", "");
// Copy incoming record set table to new feature class's table
ITable table = (ITable) pFeatClass;
table = rs.Table;
IFeatureClass result = table as IFeatureClass;
// It will probably work OK without this, but it makes the XML match more closely
IClassSchemaEdit3 schema = result as IClassSchemaEdit3;
schema.AlterAliasName(sName);
schema.AlterFieldAliasName("FID", "");
schema.AlterFieldModelName("FID", "");
schema.AlterFieldAliasName("Shape", "");
schema.AlterFieldModelName("Shape", "");
// If individual fields need to be edited, do something like this:
// int nFieldIndex = result.Fields.FindField("Shape");
// IFieldEdit2 field = (IFieldEdit2)result.Fields.get_Field(nFieldIndex);
// Cleanup
DeleteExistingDataset(pFWS, sName);
return table as IFeatureClass;
}
Finally, a utility method for deleting an existing dataset. This was copy/pasted from somewhere, but I can't remember the source.
public static void DeleteExistingDataset(IFeatureWorkspace pFWS, string sDatasetName)
{
IWorkspace pWS = (IWorkspace)pFWS;
IEnumDatasetName pEDSN = pWS.get_DatasetNames(esriDatasetType.esriDTFeatureClass);
bool bDatasetExists = false;
pEDSN.Reset();
IDatasetName pDSN = pEDSN.Next();
while (pDSN != null)
{
if (pDSN.Name == sDatasetName)
{
bDatasetExists = true;
break;
}
pDSN = pEDSN.Next();
}
if (bDatasetExists)
{
IFeatureClass pFC = pFWS.OpenFeatureClass(sDatasetName);
IDataset pDataset = (IDataset)pFC;
pDataset.Delete();
}
}