How do you get ServiceStack.ToJson to *sometimes* ignore properties? - servicestack

I have a ServiceStack DTO:
[Route("/images", "POST")]
public class PostImageCommand
{
public string Notes { get; set; }
public byte[] Image { get; set; }
//other properties removed for brevity
}
I also have a part in my code that logs messages using log4net. I do this by serializing the command. For example, I just do this:
var command = new PostImageCommand(){
//set properties
};
var commandJson = command.ToJson();
MyLogClass.Log(commandJson);
The problem: The Image byte array can get pretty large. I do not want to serialize this property when logging, or else my log will be filled with large amounts of image data.
I tried putting the [IgnoreDataMember] attribute on the Image byte[] in the DTO. However, that causes the build to fail without Visual Studio saying why. I can put the Attribute on the Image property, but when I try to build I see this:
No reason why the build failed, just these messages. The Output tab only says "The operation was canceled".
My question: What is the easiest way to ignore a DTO property from being serialized in my situation?

This previous answer lists the different ways to ignore properties in ServiceStack.Text. But really if you just want to ignore the property from being logged you can just set the property to null then restore it, map it to a different model with just the types you want serialized using the built-in AutoMapping tools, Use ToObjectDictionary() extension method to serialize your model into a dictionary then remove the items you don't want logged.
The issue you're having with the [IgnoreDataMember] attribute is because you haven't referenced the System.Runtime.Serialization .NET Framework Assembly.

Related

How to spec base64 encoded object in query param in OpenAPI

I am trying to document an existing API using the OpenAPI spec (specifically using Swashbuckle and ASP.NET Core).
For many of the endpoints, the api uses a single query parameter which is a filter object – holding the actual parameters – that is base64-encoded.
I have successfully added the Swashbuckle library and can generate a swagger.json.
The generated spec however does not correctly describe the endpoints described above. Rather, the property names of the filter object are stated as query parameters, and thus autogenerated clients based off the spec do not work.
The spec mentions base64 only in relation to format of String and File, not Object.
Is it possible (and if so, how) to describe this type of endpoint in OpenAPI?
Is it possible (and if so, how) to generate this description correctly using Swashbuckle?
EDIT
In response to comment (probably necessary for answering subquestion 2) ).
An endpoint in the API source may look something like:
[HttpGet("")]
public async Task<IActionResult> Query([FromQuery] ThingFilter filter)
{
var results = await _dataContext.ThingService.Search(filter);
return Ok(results);
}
And a ThingFilter might be something like:
public class ThingFilter
{
public string Freetext { get; set; }
public List<PropertyFilter> PropertyFilters { get; set; }
}
In Startup.cs there is also registered a custom modelbinder that handles conversion from base64.

Automapper isn't using extension methods for mapping

I have automapper setup like this
services.AddAutoMapper(typeof(MappingAssembly).Assembly, typeof(AssemblyWithExtensionMethods).Assembly);
And in one of my profiles
public class UserModuleMapper : Profile {
public UserModuleMapper() {
IncludeSourceExtensionMethods(typeof(UserGroup));
CreateMap<UserGroup, UserGroupDto>(MemberList.Destination);
}
}
And I have defined the extension method as
public static List<string> GetRoleNames(this UserGroup group) {
return group.UserGroupRoles.Select(x => x.Role.Name).ToList();
}
I have a property on DTO defined as
public List<string> RoleNames { get; set; }
As per the automapper documentation, I have made the following assumptions:
IncludeSourceExtensionMethods, which include extension methods while mapping
while mapping it will also look for methods with prefix Get
But when I validate the automapper extension I get error for unmapped property
Unmapped properties: RoleNames
What is missing in my configuration, automapper should detect the extension method.
I have tried (a) remove GET from the method name, but still does not work (b) moving CreateMap before or after the IncludeSourceExtensionMethods to see if sequence matters, but none of it helped.
With in few minutes after posting the question I got the answer by carefully looking at this issue on Github
The issue was with below statement
IncludeSourceExtensionMethods(typeof(UserGroup));
the type mentioned here should be of extension class
IncludeSourceExtensionMethods(typeof(UserGroupExtensions));
Not deleting the question, as it might help someone in future.

Omitting fields during serialization for specific Gson serializer

I have a stateless REST API build on Spring Boot 1.4.2. I want to log all the API calls into elk. Requests and responses data (headers, parameters, payload) need to be logged as well. I don't want to log them 1:1 - I want to filter out sensitive data etc.
I made an aspect that is intercepting my #RestController's methods invocation. I created custom annotation for method's parameter that should be logged (I use it on payloads annotated as well by #RequestBody) following this article and it gave me access to my data transfer objects in my #Around advice. I dont care about their type - I would like to call logger.debug(logObject) and send this log to logstash.
As far as I understand log message should be send as JSON with JSONLayout set in Log4j2 appender to ease things on the logstash side. So I serialize my logObject into JSON log message but during this and this only serialization I want to filter sensitive data out. I can not use transient because my controller depends on the same field.
Can I somehow create an #IgnoreForLogging annotation, that will be detected only by my custom Gson serializer that I use within logging advice and will be ignored within standard Spring's infrastructure? Is my logging into logstash approach even correct (I am trying to set it up for the first time)?
I can't believe I missed that in documentation. Here is the link
My custom annotation:
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.FIELD)
public #interface IgnoreForLogging {
}
Strategy for serializing objects:
public class LoggingExclusionStrategy implements ExclusionStrategy {
#Override
public boolean shouldSkipField(FieldAttributes fieldAttributes) {
return fieldAttributes.getAnnotation(IgnoreForLogging.class) != null;
}
#Override
public boolean shouldSkipClass(Class<?> aClass) {
return false;
}
}
Serializing log message in aspect class:
Gson gson = new GsonBuilder()
.setExclusionStrategies(new LoggingExclusionStrategy())
.create();
String json = gson.toJson(logObject);
This way Spring internally uses default serializer that doesn't know about #IgnoreForLogging and I can take advantage of my annotation in other places.

How to use ObjectContext with Model Builder?

Is there a way we can use ObjectContext with DbContext's ModelBuilder? We don't want to use POCO because we have customized property code that does not modify entire object in update, but only update modified properties. Also we have lots of serialisation and auditing code that uses EntityObject.
Since poco does create a proxy with EntityObject, we want our classes to be derived from EntityObject. We don't want proxy. We also heavily use CreateSourceQuery. The only problem is EDMX file and its big connection string syntax web.config.
Is there any way I can get rid of EDMX file? It will be useful as we can dynamically compile new class based on reverse engineering database.
I would also like to use DbContext with EntityObject instead of poco.
Internal Logic
Access Modified Properties in Save Changes which is available in ObjectStateEntry and Save them onto Audit with Old and New Values
Most of times we need to only check for Any condition on Navigation Property for example
User.EmailAddresses.CreateSourceQuery()
.Any( x=> x.EmailAddress == givenAddress);
Access Property Attributes, such as XmlIgnore etc, we rely heavily on attributes defined on the properties.
A proxy for a POCO is a dynamically created class which derives from (inherits) a POCO. It adds functionality previously found in EntityObject, namely lazy loading and change tracking, as long as a POCO meets requirements. A POCO or its proxy does not contain an EntityObject as the question suggests, but rather a proxy contains functionality of EntityObject. You cannot (AFAIK) use ModelBuilder with EntityObject derivatives and you cannot get to an underlying EntityObject from a POCO or a proxy, since there isn't one as such.
I don't know what features of ObjectContext does your existing serialisation and auditing code use, but you can get to ObjectContext from a DbContext by casting a DbContext to a IObjectContextAdapter and accessing IObjectContextAdapter.ObjectContext property.
EDIT:
1. Access Modified Properties in Save Changes which is available in ObjectStateEntry and Save them onto Audit with Old and New Values
You can achieve this with POCOs by using DbContext.ChangeTracker. First you call DbContext.ChangeTracker.DetectChanges to detect the changes (if you use proxies this is not needed, but can't hurt) and then you use DbCotnext.Entries.Where(e => e.State != EntityState.Unchanged && e.State != EntityState.Detached) to get DbEntityEntry list of changed entities for auditing. Each DbEntityEntry has OriginalValues and CurrentValues and the actual Entity is in property Entity.
You also have access to ObjectStateEntry, see below.
2. Most of times we need to only check for Any condition on Navigation Property for example:
User.EmailAddresses.CreateSourceQuery().Any( x=> x.EmailAddress == givenAddress);
You can use CreateSourceQuery() with DbContext by utilizing IObjectContextAdapter as described previously. When you have ObjectContext you can get to the source query for a related end like this:
public static class DbContextUtils
{
public static ObjectQuery<TMember> CreateSourceQuery<TEntity, TMember>(this IObjectContextAdapter adapter, TEntity entity, Expression<Func<TEntity, ICollection<TMember>>> memberSelector) where TMember : class
{
var objectStateManager = adapter.ObjectContext.ObjectStateManager;
var objectStateEntry = objectStateManager.GetObjectStateEntry(entity);
var relationshipManager = objectStateManager.GetRelationshipManager(entity);
var entityType = (EntityType)objectStateEntry.EntitySet.ElementType;
var navigationProperty = entityType.NavigationProperties[(memberSelector.Body as MemberExpression).Member.Name];
var relatedEnd = relationshipManager.GetRelatedEnd(navigationProperty.RelationshipType.FullName, navigationProperty.ToEndMember.Name);
return ((EntityCollection<TMember>)relatedEnd).CreateSourceQuery();
}
}
This method uses no dynamic code and is strongly typed since it uses expressions. You use it like this:
myDbContext.CreateSourceQuery(invoice, i => i.details);

WebAPI get not converting properly to model binding object

I"m using WebAPI with MVC4, doing a http get that looks like this:
api_version=2&products=[{"id":97497,"name":"iPad"}]&pageno=1
The signature of the get action controller that maps to this call is:
[HttpGet]
public string Get([FromUri] ProductRequest request){ ... }
The problem is that the ProductRequest object passed into the Get action method above contains nulls for products, while all other values are Ok.
So it seems that it has trouble converting products=[{"id":97497,"name":"iPad"}] into the right object type, which is defined as:
public IEnumerable<Products> products { get; set;} in ProductRequest model and Products class looks like:
public int id { get; set; }
public string name { get; set; }
As, an additional information, when using the same call with a POST instead of a GET, it works fine, the object is converted properly.
So, what am I doing wrong, how can I get http GET to properly convert the query parameters to the model passed in?
I think you confused between HTTP POST and HTTP GET that's why you did get the product as null. You could have a look at What's the difference between GET and POST
Basically, I think you could use TempData but it has pros and cons and depend on the context how you use it.
You can do it through the url, but you don't use JSON. Here's what your URL should look like:
api_version=2&products[0].id=97497&products[0].name=iPad&pageno=1
If you wanted to add more products in the same request, you would increment the array index:
{urlasabove}&products[1].id=4234&products[1].name=iPadmini
This is fine for your request, but can quickly get out of hand. For a complex object in a GET request you may consider using a POST instead. Or, you could include the parameters in the GET body but that's not necessarily the best idea. See discussion on this SO question.

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