i'm looking to load a list of object with their child graph in subsonic. I know how to do it using linq to sql with dataloadoptions
i have this graph
product
- location
- prices
new Select().From().Where(Product.Columns.Id).IsEqualTo(productId).ExecuteSingle();
I would like for my product object to preload location and prices, so that they would not lazy load causing many query.
thanks
I use the RepositoryRecord in SubSonic which is "mostly" poco. Then I make partials for those classes that load the other class when a property is selected. Besides, loading one record from the database is faster and easier than loading them all at once.
Partial Public Class Book
Private _Author as Database.Author
Property Author() as Database.Author
Get
If _Author is nothing then
' Load the author class here.
End if
return _Author
End get
Set
'....
End Set
End Property
End Class
Related
I would like to make a Plugin where the user can select a source and then a target element and get all the parameters and their values.
My problem is: After I selected the source element and got all parameters and values into comboboxes I select the target (via another button). For that the form closes again and after selecting and reopening all the data from the source element is gone.
What would be a correct way to do this?
At this time both buttons close the form run another ExternalEvent to select the element and collect the data.
Can I cache this data (Lists, dictionary with list, dictionary with dictionary with list) or do I have to write it to a file or is there another way?
How do I keep/remember the data I collected when a form closes an reopens?
Thank you for any help
Philipp
There multiple ways of doing this I guess. It is more of a general programming rather than API issue. You basically need to keep the data in memory outside of just the WPF window.
Some options of the top of my head would be
Save the data into file in temp folder and read it when needed (probably a messy solution)
Create & instantiate a class with data to keep in memory and communicate it between different windows etc.
Have a Static Class with appropriate property. Once selecting an element assign it to the property. This should persist within the Revit session. Static Class.
Option 3 should be the easiest to use.
Just use Properties -> Application settings to store the ID of the entity. Then on launch get the combo boxes to auto populate if the ID can be found.
External events are only required when editing the model.
This is assuming your using Visual studio and not sharp develop. If your still using sharp develop it is time to move on to a real IDE.
I think there are a few options. You could use the built in DataStorage that a revit model provides. Here, i made a datastorage entity to store a GUID for a project...
public Guid schemaGuid = new Guid("{5F374308-9C59-42AE-ACC3-A77EF45EC146}");
public DataStorage dataStorage;
public string schemaName = "UniqueProjectId";
public DataStorage dataStorage;
public string SimpleField = "MyProjects_GUID";
public Schema CreateNewDataStorage()
{
Guid newProjectGuid = Guid.NewGuid();
Transaction t = new Transaction(doc, "Make internal storage");
t.Start();
dataStorage = DataStorage.Create(doc);
dataStorage.Name = schemaName;
SchemaBuilder schemaBuilder = new SchemaBuilder(schemaGuid);
schemaBuilder.SetSchemaName(schemaName);
schemaBuilder.AddSimpleField(SimpleField, typeof(Guid));
schema = schemaBuilder.Finish();
entity = new Entity(schema);
entity.Set(SimpleField, newProjectGuid);
dataStorage.SetEntity(entity);
t.Commit();
return schema;
}
Another way would be to write to external database or text file. For something small, SQlite is easy. A temporary text file is also a very simple way to temporarily store data.
Lastly, you could use an Idling event and keep the dialogue box active.
When handling the Selected event of a EntityDataSource, the Results property of the EntityDataSourceSelectedEventArgs returns an ObjectView collection of my entities. I'm not sure what this class is. This link to the Namepace doesn't mention the class.
Is there any documentation on this System.Data.Objects.ObjectView collection class? How would I convert an ObjectView<T> to a List<T>? Perhaps it's as simple as enumerating the collection and adding the items to a new List<T>, but some information about the class would be useful.
The ObjectView class is internal and therefore you cannot find it on MSDN. The important bit of information is that it implements IBindingListInterface
What is the difference between the System.ComponentModel.BindingList methods Add(object) and AddNew()? The MSDN documentation says this:
Add: Adds an object to the end of the Collection<T>.
AddNew: Adds a new item to the collection.
It seems like both methods add an item to the collection, but Add(object) does it in one shot whereas AddNew() is slightly more complicated. My tests with Add(object) seem to be working, but I want to know if I am using the correct method.
So what is the difference between these methods?
AddNew() creates the object for you (that's why it doesn't have a parameter).
It's designed to be used by grids, which don't know how to create a new object to pass to Add().
AddNew() is very handy (it’s the well-known Factory design pattern) when you implement a class derived of BindingList().
It allows your code to initialize new items with values that depend on the list itself - e.g. a foreign key to the parent object if the binding list contains a list of children.
I think this is more of a polymorphism question but it applies to SubSonic table objects...
Here's the thing (and I love this one):
TblUser userObj = new TblUser(1);
Which fills userObj's properties with all of PK=1's goodies.
Now, I'd like to add more properties to the existing user object, for example, an ArrayList property of say, account numbers.
I've seen questions like this around - "add a property to an existing object...", but in this case, would it be most-recommended to create a user wrapper object, then have a TblUser property type, and my own other additional properties in this?
Ok, so it looks like once-again I have come up with a solution to this, but am still curious about the possibility of adding properties to existing objects.
All the generated SubSonic classes are partials so all you need to do to add extra properties/methods to them is to create your own partial class with the same name in the same namespace and the two will be merged at compile time. For example for your TblUser class:
public partial class TblUser
{
public List<AccountNumber> AccountNumbers
{
get
{
// Get and return the AccountNumbers
}
}
}
I want to follow the DDD philosophy and not access entity objects of an aggregate directly. So, i have to call the root object to get the associated entity. But In other cases I dont always want every associated entity to load when the root is called. Is that the purpose of lazy loading?
How do I access entity objects through the root without loading all the associated objects everytime if i disable lazyloading feature of linq?
EDIT:
For example, If I have a Person as the Root Entity, and the Person has Name, Addresses and OwnedProperties. If I want to get a list of People so that I could display their names, I dont necvessarily want to load up Owned Properties every time on the call to the Repository. Conversely, on another page I may want to show a list of OwnedProperties, but do not want the other information to load with the call. what is the simple way of just calling the Person without the owned property entity other than creating a new person object without that owned properties?
I don't thinks that's possible without lazy loading.
Getting all data at once: Eager Loading
Getting data when accessed: Lazy Loading
According to your edit:
What I do in these situations, is create a 'View' class or a 'DTO' class which just contains the properties that I'm interested in.
For instance, I could have a 'PersonView' class which just has a Name property for instance.
Then, using my OR/M mapper (I use NHibernate), I create a HQL query (or Criteria query) which works on my 'Person' entity. Before I execute the query, I tell NHibernate that I want 'PersonView' objects as a result (I specify a projection). Then, NHibernate is smart enough to execute a query that only retrieves the columns that are necessary to populate the PersonView instances.
One way to avoid lazy loading is just using the object 'id'