I have a simple set of 20+ classes. They are all serializable to allow use of these objects within a web service. (DataContract/DataMember) Each of them has an ID and a variable number of other properties, depending on the class.
And I have a database which will store just an ID, a Name that identifies the class and an XML string. And this XML is also the same data in serialized form, but without one property: the ID field should not be stored, since it's redundant.
But the ID must still be sent to the client of the web service, making things a bit complex. And although I could just create a copy of each class, where one has the ID as DataMember and the other doesn't, I'm just looking for a much cleaner solution to solve this. One where I would not need to store the ID field as part of the XML within the database.
So, question: what is the simplest solution to make sure the ID becomes part of the data that's sent to the client, but skipped when storing it as XML? (Without the need of hacking in the XML to remove it.)
And although I could just create a copy of each class, where one has
the ID as DataMember and the other doesn't
What about inheritance?
public class MyEntity
{
// some props
}
public class MyEntityWithId : MyEntity
{
public int Id { get; set; }
// some props
}
Related
I have created a class to store data from API calls I am making. It returns JSON with some meta information, and then an array of data depending on the call being made. The meta information will always have the same fields, so I have created a "Root" class for this, but the data will be different depending on the call being made, so I have created different classes for each type of data, e.g. user data, company data, etc. As shown below, I currently have the "data" property set to a list of objects, but I am trying to figure out the best way to incorporate the different types of data that can be returned, since it will vary based on the call being made.
Right now I have the data saved as a list of objects, but I would like this to change depending on what data I am receiving. Like, if I am retrieving users, I would like for it to be a list of users.
What is the ideal way to accommodate for this? The only way I can think to do it now is to create a different "Root" class for every type of data I am expecting to receive, but that doesn't feel like it should be the most concise way to do it. I was looking into making this a factory design pattern but I wasn't sure that it fit this scenario.
Just use a generic base class:
public abstract class ApiCallResult<T>
{
// With your properties
// public int Limit { get; set; }
// [...]
//
public IEnumerable<T> Data { get; set; }
}
Then define a result per api call.
public class UserApiCallResult : ApiCallResult<User>
{
}
Created a small working example here:
dotnet fiddle
I have a situation where I need to deserialise XML to a model, and then map that model using automapper to another model.
The issue is that the XML is structured in such a way that the element names match the properties in the model that I'm initially trying to map to...but for the most part the actual data is in an attribute called 'Val' in the element e.g.:
<Vehicle>
<RegNo Val="ABC123A"/>
</Vehicle>
Now the normal way to do such a mapping, I think, would be (I've not bothered with a root element!):
[XmlElement("Vehicle")]
public class Vehicle {
[XmlElement("Regno")]
public Regno Regno { get; set; }
}
public class Regno {
[XmlAttribute]
public string Val {get;set;}
}
That would allow the XML to map to the 'holding' object, but it does mean that rather than referencing a string called Regno, making the mapping to the second model fairly simple, I would have to reference Regno.Val. This doesn't sound a lot, but there's a lot of elements in the XML, and some of them use differently named attributes and the like. What I'd really like to do is define all the heavy lifting in the holding model defintion, using XMLAttributes etc. along the lines of:
[XmlElement("Vehicle")]
public class Vehicle {
[XmlElement("Regno.Val")]
public string Regno { get; set; }
}
So almost like being able to supply a path, or qualified value name. Effectively, moving the data one place up the hierarchy if that makes sense!
Is it possible to do this? I mean I could set up bespoke mappings in the automapper for moving from the holding model to the main model, but it would simpler if I could just go through the properties in the assemblies for each model and map from one to the other. Also given that not all the attributes are called 'Val', it could make things a bit messy, and it would be better if I could deal with it at the outset at the time the data is deserialised.
Edit: Should have added that I've tried the 'path' approach and couldn't get it to work, so I should have asked 'Am I doing it wrong?'
I've been working with some serializable classes recently and they typically look something like this:
[DataContract]
public class Foo
{
[DataMember(Order = 0)]
public string Bar1
{
get;
set;
}
[DataMember(Order = 1)]
public string Bar2
{
get;
set;
}
}
I was wondering, what possible application could one have for specifying an order for the data members? The guidelines here specify that it may "Sometimes it may be necessary to change this order." but don't give any examples of when or why. Do you have any examples of when or why this may be necessary?
In my application I am simply serializing these objects of these types and saving them down to a file. Does specifying an "Order" here have any value or does it simply add something else to maintain? Would I face any problems if I simply removed "Order" from each data member?
Order specifies the order in which data members are serialized into an object, otherwise they'll be arranged alphabetically.
In some applications, it is useful to know the order in which data
from the various data members is sent or is expected to be received
(such as the order in which data appears in the serialized XML).
One of the scenarios where you would like to order your data members when you are sending response to a client with pre-defined object structure.
Refer this question for example.
Also sometimes you might be interested in showing the ID field (or similar) first, and then all the other fields, to make raw xml look end-user friendly.
And yes you won't get any error if you don't mention order.
Refer docs here
Where I work, we have a C# API that interfaces with a third-party system that uses an unusual method of database interaction in which field order is very important. When serializing an object that represents a record from a table in that system into a format that said system can understand, it is useful to us to have this order represented in the C#.
In short, it can be useful if order matters to whatever 'thing' is consuming the serialized data from the object.
I have an issue with the project I'm working on. I'm using Entity Framework. Some quick background on the db model:
public class AssetType{
public ICollection<Field> Fields { get; set; }
}
public class Field{
public int Id {get;set;
public string Name {get;set;
}
Now I'm creating a view that would create a new Asset Type. As part of this process the user must also create all of the fields they want for that type. The issue is that I'm not sure how to represent the list of "Fields" on the page. The idea is that the user can add a new field, or remove one at any time with jQuery.
I can't figure how the data could be posted back to the server as part of the form. I thought about constructing the list in JSON form, but this seemed a bit messy. Has anyone got any better ideas?
You're going to have problems with this. The object parser does not handle complex objects very well. Collections usually need to be primitive types, or collections of primitive types themselves.
There are ways to do it, but if this is a requirement for you, I would look at storing your data in a JSON string variable, and parsing it where/ when needed.
Imagine I've got a data object that makes sense in an OO model, but for serialization I want to have its fields referencing other types replaced with simply an ID, or in some cases, a simple object with a text and an ID.
Is it possible to have the serializer to handle specific fields differently, or do I have to redefine a second data object class from scratch with the simplified fields and use that?
Example:
Person
Guid Id
string Name
List<Person> Siblings
What I want to be serialized:
Person
Guid Id
string Name
List<Guid> Siblings
I would like to only have the one class, Person, and define the serialization behavior for my service (preferably not at a data type level, since it could be serialized as both XML or JSON).
I know about the support for references in WCF, but in this case I will be referencing other types not included elsewhere in the result set; I only want to include their ids.
You could exclude Siblings property from serialization and add a readonly SiblingGuids:
Person
Guid Id
string Name
[NonSerialized]
List<Person> Siblings
List<Guid> SiblingGuids // Only a getter which will expose guids
Once you change the structure of the information being transmitted, a data transfer object is probably the cleanest and simplest choice.
In fact, I would always recommend creating dedicated DTOs for WCF services, to separate the service and the data it transmits from the domain model I'm normally working against. There is the overhead of managing changes with the model and service separately, but it's much less work than having to force your domain objects into the right shape for your service and then trying to keep them there.