How to dynamically assign generic Type

Question

5.00/5 (1 vote)

See more:

Generic class:

C#

public class GenericEntityMapping
{
    public T Map<t>(XmlNode xNode, T entityObject)
    {
        //FYI.
        //PropertyInfo[] entityProperties = typeof(T).GetProperties();
        //foreach (PropertyInfo pInfo in entityProperties){...}

        //somewhere in the code depends on the condition.
        if true then...
        GenericEntityMapping<SampleEntity01>.Map(node, new SampleEntity01())
        .
        .
        .
        else if true then...
        GenericEntityMapping<SampleEntity02>.Map(node, new SampleEntity02())
    }
}

How can i do it where the type in the generic needs not to be hardcoded?

My goal is something like:
Type myType = pInfo.PropertyType.GetType();
GenericEntityMapping<myType>.Map(node, System.Activator.CreateInstance<myType>());

Is it possible?

Posted 1-Nov-11 17:12pm

Jephunneh Malazarte

Updated 1-Nov-11 18:56pm

v6

Add a Solution

Comments

Sergey Alexandrovich Kryukov 1-Nov-11 23:19pm

How come you have a problem with that in principle? Any particular problem?
--SA

Jephunneh Malazarte 2-Nov-11 1:00am

Hello SA - the problem arise when mapping the xmlnode to the entities where the number of xml nodes are not constant. example: <MYPARENTNODE><MYCHILD><NAME>my name</NAME> <AGE>12</AGE> </MYCHILD><OTHERCHILD>... </OTHERCHILD>. . . </MYPARENTNODE>however there are cases that it has only one child node.. so the requirement is to mapped the nodes to the entity and i was thinking that maybe it would be less coding modification if i do it dynamically.

Jephunneh Malazarte 2-Nov-11 1:59am

May I ask, if the requirement is to mapped the xmlnodes to the entity. how will you do it? Thanks in advance. My code is not finally though and it's good to have variety of solutions... hope you don't mind me asking SA. :)

BillWoodruff 2-Nov-11 0:41am

+5 for this interesting question, thanks ! Am I correct in assuming that this question is asked in the context of using nHibernate or EF ?

Jephunneh Malazarte 2-Nov-11 1:04am

hello Bill - somewhat related to EF :) thanks.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Accepted Answer · 2011-11-01T17:18:00

Solution 1

For a type, being generic and begin static are not related. Both generic and non-generic types can be static or not static.

—SA

Posted 1-Nov-11 17:18pm

Sergey Alexandrovich Kryukov

Comments

Jephunneh Malazarte 2-Nov-11 0:11am

thanks for your reply and yes you are right sorry my bad. I use a wrong terminology instead of hardcoded i use static. Sorry about that.

Sergey Alexandrovich Kryukov 2-Nov-11 1:07am

Unfortunately, you still use hard-coded "Map". I the type GenericEntityMapping was mine, I would easily avoid it. I would make it implementing an interface with the only method Map and would find MethodInfo through this interface.

Now, is GenericEntityMapping your type? If so, you could greatly improve your approach.

--SA

Jephunneh Malazarte 2-Nov-11 1:42am

oh no.. the Map is the generic function that i need to call recursively the GenericEntityMapping is my generic class where the Map function is located. I am curious which part of the code that I need to improve. Any inputs are appreciated. FYI. The EntityType are the one that I need to be dynamic.

-- New --
thanks for the add-on i will use interface to prevent any hardcoded value :) thanks SA.

thanks in advance SA.

Sergey Alexandrovich Kryukov 2-Nov-11 21:48pm

Maybe you can explain more on the ultimate goals of this activity. What Map does What entity mapping does? Why there are several SampleEntities in the pseudo-code? Do you want to get rid of each of them?
--SA

Jephunneh Malazarte 3-Nov-11 8:02am

Business Requirements:
There is a separate website that manages all application. Lets name it as "One Website", then it manages 2 system the System A and System B. The one website will generate the dynamic fields depending on which system the user selected. These dynamically generated fields will be stored into XML file along with other related/unrelated information.

Now in order for the System A to processs the request triggered by the "one website" the System A needs to expose a web service (i am using restful approach here). One website will call the service of System A and pass on the XML.

Question:
What approach can you suggest in order to save the selected data from XML to my database tables?

What I did here:
Is that I have database tables and i have created an entity class that contains the db tables columns. Then crated a function to map the xml nodes to my entity objects.

I have posted my solution here: http://jephunnehrm.xanga.com/756318399/mapping-of-xml-node-to-entity-objects/
feel free to add suggestion for improvement...

Really appreciate your response and sorry for the hassle :p

Jephunneh Malazarte 3-Nov-11 23:19pm

The idea of what i did is more of:
Extract data from XML => Store it to Entity Objects => Final saving to Database.

Espen Harlinn 2-Nov-11 21:14pm

5'ed.
And entirely unrelated to the question - here is a nice set of libraries
http://www.mono-project.com/Libraries
Not sure all them is distributed with the main mono distribution

Sergey Alexandrovich Kryukov 2-Nov-11 21:39pm

Thank you, Espen. Special thanks for the link. In particular, I was pleased to see Indy familiar by Delphi.
--SA

Jephunneh Malazarte · Accepted Answer · 2011-11-01T18:13:00

Hello SAKryukov,
Thanks for the quick reply.

I found the solution:

C#

MethodInfo method = typeof(GenericEntityMapping).GetMethod("Map");
MethodInfo generic = method.MakeGenericMethod(Type.GetType(pInfo.PropertyType.FullName));

object[] objParam = { node, System.Activator.CreateInstance(Type.GetType(pInfo.PropertyType.FullName)) };
pInfo.SetValue(entity, generic.Invoke(this, objParam), null);