Get entity object's property names excluding entitycollection and entityreference

Question

I am working on a method that compares two objects using reflection. The object types are objects created from entity framework. When I use GetProperties() I am getting EntityCollection and EntityReference properties. I only want the properties that belong to the object and not any associated properties or references from foreign keys.

I've tried the following How to get all names of properties in an Entity?.

I thought about passing an array of properties to compare but I don't want to have to type them in for each object type. I am open to some suggestions even those that don't use reflection.

public bool CompareEntities<T>(T oldEntity, T newEntity)
{
    bool same = true;
    PropertyInfo[] properties = oldEntity.GetType().GetProperties();

    foreach (PropertyInfo property in properties)
    {
        var oldValue = property.GetValue(oldEntity, null);
        var newValue = property.GetValue(newEntity, null);

        if (oldValue != null && newValue != null)
        {
            if (!oldValue.Equals(newValue))
            {
                same = false;
                break;
            }
        }
        else if ((oldValue == null && newValue != null) || (oldValue != null && newValue == null))
        {
            same = false;
            break;
        }
    }
    return same;
}

Are these entities POCOs or derived from `EntityObject`? – Eranga Jan 04 '12 at 03:55 — Eranga, Jan 04 '12 at 03:55

score 4 · Accepted Answer · edited May 23 '17 at 12:15

Using the suggestions from @Eranga and https://stackoverflow.com/a/5381986/1129035 I was able to come up with a workable solution.

Since some of the properties in the root object are a GenericType there needs to be two different if statements. Only if the current property is an EntityCollection skip over it.

public bool CompareEntities<T>(T oldEntity, T newEntity)
{
    bool same = true;
    PropertyInfo[] properties = oldEntity.GetType().GetProperties(BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance)
        .Where(pi => !(pi.PropertyType.IsSubclassOf(typeof(EntityObject)))
        && !(pi.PropertyType.IsSubclassOf(typeof(EntityReference)))
        ).ToArray();

    foreach (PropertyInfo property in properties)
    {
        if (property.PropertyType.IsGenericType)
        {
            if (property.PropertyType.GetGenericTypeDefinition() == typeof(EntityCollection<>))
            {
                continue;
            }
        }

        var oldValue = property.GetValue(oldEntity, null);
        var newValue = property.GetValue(newEntity, null);

        if (oldValue != null && newValue != null)
        {
            if (!oldValue.Equals(newValue))
            {
                same = false;
                break;
            }
        }
        else if ((oldValue == null && newValue != null) || (oldValue != null && newValue == null))
        {
            same = false;
            break;
        }
    }

    return same;
}

score 2 · Answer 2 · answered Sep 02 '15 at 21:14

2

make it easy for yourself and do this instead

PropertyInfo[] properties = oldEntity.GetType().GetProperties(pi=> pi.PropertyType.NameSpace=="System").ToArray();

answered Sep 02 '15 at 21:14

alex

21
1

you rock. This fixed my own issue :) – Richard Griffiths Aug 10 '17 at 12:43

score 2 · Answer 3 · answered Jan 04 '12 at 04:09

2

Try filtering out EntityObject type and EntityCollection properties.

var properties = oldEntity.GetType().GetProperties().
                   Where(pi => !(pi.PropertyType.IsSubclassOf(typeof(EntityObject))
                   || pi.PropertyType.IsSubclassOf(typeof(EntityCollection));

answered Jan 04 '12 at 04:09

Eranga

32,181
5
97
96

EntityCollection requires a type to be set. – wsamoht Jan 04 '12 at 04:47
Sorry trying to figure out stackoverflow :) I changed to this: `PropertyInfo[] properties = oldEntity.GetType().GetProperties(BindingFlags.DeclaredOnly | BindingFlags.Public | BindingFlags.Instance).Where(pi => !(pi.PropertyType.IsSubclassOf(typeof(EntityObject))) && !(pi.PropertyType.IsSubclassOf(typeof(EntityReference)))).ToArray();` Now only EntityCollections need to be excluded. – wsamoht Jan 04 '12 at 04:51
My question now is how to remove the EntityCollection objects from the property list – wsamoht Jan 04 '12 at 17:34
@curiousg modify the `Where` condition to filter out `EntityCollection`. – Eranga Jan 05 '12 at 00:12

Get entity object's property names excluding entitycollection and entityreference

3 Answers3