I'm attempting to follow the logic describe here: https://msdn.microsoft.com/en-us/library/gg309282.aspx for creating associated entities using the RelatedEntities Property. Problem is, no Associated Entities are getting created. I'm attempting to perform this action from within a Pre=Operation plugin... Is it not supported within a PreOperation Plugin? What am I doing wrong if it?
Here is the code:
var collection = new EntityCollection();
collection.Entities.AddRange(incentives.Select(e => e.ToSdkEntity()));
target.RelatedEntities.Add(new Relationship(new_LeadProduct.Fields.new_lead_new_leadproduct_LeadId), collection);
Since a pre-create plugin executes before the target entity has been created in the database you will not be able to create related entities referencing the target. You should execute related entity logic in a post-create plugin.
Edit:
This answer applies if you are trying to create related records associated with the Target in a plugin operation. Your question did not specify otherwise but based on the code in your answer it looks like this is not what you are trying to do.
Here is the code from the MSDN Example:
//Define the account for which we will add letters
Account accountToCreate = new Account
{
Name = "Example Account"
};
//Define the IDs of the related letters we will create
_letterIds = new[] { Guid.NewGuid(), Guid.NewGuid(), Guid.NewGuid() };
//This acts as a container for each letter we create. Note that we haven't
//define the relationship between the letter and account yet.
EntityCollection relatedLettersToCreate = new EntityCollection
{
EntityName = Letter.EntityLogicalName,
Entities =
{
new Letter{Subject = "Letter 1", ActivityId = _letterIds[0]},
new Letter{Subject = "Letter 2", ActivityId = _letterIds[1]},
new Letter{Subject = "Letter 3", ActivityId = _letterIds[2]}
}
};
//Creates the reference between which relationship between Letter and
//Account we would like to use.
Relationship letterRelationship = new Relationship("Account_Letters");
//Adds the letters to the account under the specified relationship
accountToCreate.RelatedEntities.Add(letterRelationship, relatedLettersToCreate);
//Passes the Account (which contains the letters)
_accountId = _service.Create(accountToCreate);
After some additional testing, the Related Entities Collection must be populated before the PreOperation stage. So registering this to run on PreValidation works as expected.
Related
I want to set many to many relationship oid key name.
In many to many relationship Oid is created automatically but on database side I want to change oid name to custom name.
For Example;
If I try to create Person and Task many to many relation. Third table attributes in below;
KomutTanim (FK to Makine)
Makine (FK to KomutTanim)
OID (PK, guid)** (I want to set this key name??)**
Tell me how can I do. I added sample code in below
[Association("Relation.KomutListesi_Makine",typeof(KomutTanim),UseAssociationNameAsIntermediateTableName = true),XafDisplayName("Makine Komutları")]
public XPCollection<KomutTanim> Komutlar
{
get
{
return GetCollection<KomutTanim>(nameof(Komutlar));
}
}
[Association("Relation.KomutListesi_Makine", typeof(Makine), UseAssociationNameAsIntermediateTableName = true), XafDisplayName("Makineler")]
public XPCollection<Makine> MasterId
{
get
{
return GetCollection<Makine>(nameof(MasterId));
}
}
You can customize XPO metadata or manually create a persistent class for your intermediate table. These approaches are illustrated in the How to implement a many-to-many relationship with an intermediate table ticket.
The solution with customizing XPO metadata uses XAF APIs to access an XPClassInfo instance via the XPDictionary property. You can access XPDictionary using only XPO methods as illustrated at How to get an XPClassInfo instance. Also, you can manually create a ReflectionDictionary instance (ReflectionDictionary is an XPDictionary descendant) as described in the How to create persistent metadata on the fly and load data from an arbitrary table article.
XPDictionary dictionary = new ReflectionDictionary();
XPClassInfo intermediateClassInfo = dictionary.GetClassInfo(typeof(KomutTanim)).FindMember(nameof(KomutTanim.MasterId)).IntermediateClass;
intermediateClassInfo.FindMember("Oid").AddAttribute(new PersistentAttribute("MyName"));
string conn = "My connection string";
IDataStore store = XpoDefault.GetConnectionProvider(conn, AutoCreateOption.SchemaAlreadyExists);
IDataLayer dl = new SimpleDataLayer(dictionary, store);
XpoDefault.DataLayer = dl;
I am building an application that will have the ability to create agenda items to discuss in a meeting. The agenda item might include one or more attachments to discuss so there is a one to many relation between the AgendaItems and the AgendaDocs models. So far, I have an insert form that looks like this:
The "Select File" button is a drive picker and the code I have inside the onDocumentSelect event is the following:
var docs = result.docs;
var createDataSource = app.datasources.AgendaDocs.modes.create;
for(var i=0; i<docs.length-1; i++){
var uniqueDraft = createDataSource.item;
createDataSource.items.push(uniqueDraft);
}
for(var i=0; i<createDataSource.items.length-1; i++){
var draft = createDataSource.item;
createDataSource.items[i].DocTitle = docs[i].name;
createDataSource.items[i].DocURL = docs[i].url;
createDataSource.items[i].DriveID = docs[i].id;
}
console.log(createDataSource.items);
The code is supposed to fill out the the List widget below the "Select File" button, but as how you see, the three items are the same. The datasource of the List widget is "AgendaDocs.modes.create" and the datasource of the insert form is "AgendaItems.modes.create".
Reading the official documentation from appmaker, makes me think it is possible since the properties of "CreateDataSource" includes "items". I need help from an expert here. Is this possible? Am I using the wrong approach?
First things first, it seems that you are trying to create records from different models and relationship between them in a one call... at this time App Maker is not that smart to digest such a complex meal. Most likely you'll need to break your flow into multiple steps:
Create (persist) Agenda Item
Create AgendaDocs records and relation with AgendaItem
Similar flow is implemented in Travel Approval template app, but it is not exactly the same as yours, since it doesn't create associations in batches.
Going back to the original question. Yep, it is possible to have multiple drafts, but not with the Create Datasource. You are looking for Manual Save Mode. Somewhere in perfect world your code would look similar to this:
// AgendaItems in Manual Save mode
var agendaDs = app.datasources.AgendaItems;
// this line will create item on client and automatically push it
// to ds.items and set ds.item to it.
agendaDs.createItem();
var agendaDraft = agendaDs.item;
// Field values can be populated from UI via bindings...
agendaDraft.Type = 'X';
agendaDraft.Description = 'Y';
// onDocumentSelect Drive Picker's event handler
var docsDs = agendaDs.relations.AgendaDocs;
result.docs.forEach(function(doc) {
// this line will create item on client and automatically push it
// to ds.items and set ds.item to it...however it will throw an exception
// with this message:
// Cannot save a foreign key association for the 'AgendaItem'
// relation because the target record has not been persisted
// to the server. To fix this, call saveChanges()
// on the data source for that record's model: AgendaItem
docsDs.createItem();
var docDraft = docsDs.item;
docDraft.DocTitle = doc.name;
docDraft.DocURL = doc.url;
docDraft.DriveID = doc.id;
});
// submit button click
agendaDraft.saveChanges();
Just for my curiosity (and future knowledge), how does Entity Framework 5 decide when to create a new object vs. referencing an existing one? I might have just been doing something wrong, but it seems that every now and then if I do something along the lines of:
using (TestDB db = new TestDB())
{
var currParent = db.Parents.Where(p => p.Prop == passedProp).FirstOrDefault();
if(currParent == null) {
Parent newParent = new Parent();
newParent.Prop = passedProp;
currParent = newParent;
}
//maybe do something to currParent here
var currThing = db.Things.Where(t => t.Prop == passedPropTwo).FirstOrDefault();
currThing.Parent = currParent;
db.SaveChanges();
}
EF will create a new Parent in the database, basically a copy of the currParent, and then set the Parent_ID value of currThing to that copy. Then, if I do it again (as in, if there's already two of those parents), it won't make a new Parent and instead link to the first one. I don't really understand this behavior, but after playing around with it for a while something like:
using (TestDB db = new TestDB())
{
var currParent = db.Parents.Where(p => p.Prop == passedProp).FirstOrDefault();
if(currParent == null) {
Parent newParent = new Parent();
newParent.Prop = passedProp;
currParent = newParent;
}
//maybe do something to currParent here
var currThing = db.Things.Where(t => t.Prop == passedPropTwo).FirstOrDefault();
currThing.Parent = db.Parents.Where(p => p.ID == currParent.ID).First();
db.SaveChanges();
}
seemed to fix the problem. Is there any reason this might happen that I should be aware of, or was there just something weird about the way I was doing it at the time? Sorry I can't be more specific about what the exact code was, I encountered this a while ago and fixed it with the above code so I didn't see any reason to ask about it. More generally, how does EF decide whether to reference an existing item instead of creating a new one? Just based on whether the ID is set or not? Thanks!
If your specific instance of your DBContext provided that specific instance of that entity to you, then it will know what record(s) in the database it represents and any changes you make to it will be proper to that(those) record(s) in the database. If you instantiate a new entity yourself, then you need to tell the DBContext what exactly that record is if it's anything but a new record that should be inserted into your database.
In the special scenario where you have multiple DBContext instances and one instance provides you this entity but you want to use another instance to work with and save the entity, then you have to use ((IObjectContextAdapter)firstDbContext).ObjectContext.Detach() to orphan this entity and then use ((IObjectContextAdapter)secondDbContext).ObjectContext.Parents.Attach() to attach it (or ApplyChanges() if you're also editing it - this will call Attach for you).
In some other special scenarios (your object has been serialized and/or you have self-tracking entities), some additional steps may be required, depending on what exactly you are trying to do.
To summarize, if your specific instance of your DBContext is "aware" of your specific instance of an entity, then it will work with it as if it is directly tied to that specific row in the database.
My problem is that I am trying to return a simple query that contains an object Story. The Story object has a UserId in the table which links to aspnet_users' UserId column. I have created a partial class for Story that adds the UserName property since it does not exist in the table itself.
The following query gets all stories; however, a pagination helper takes the query and returns only what's necessary once this is passed back to the controller.
public IQueryable<Story> FindAllStories(){
var stories = (from s in db.Stories
orderby s.DateEntered descending
select new Story
{
Title = s.Title,
StoryContent = s.StoryContent,
DateEntered = s.DateEntered,
DateUpdated = s.DateUpdated,
UserName = s.aspnet_User.UserName
}
);
return stories;
}
When the helper does a .count() on the source it bombs with the following exception:
"Explicit construction of entity type 'MyWebsite.Models.Story' in query is not allowed."
Any ideas? It's not a problem with the helper because I had this working when I simply had the UserName inside the Story table. And on a side note - any book recommendations for getting up to speed on LINQ to SQL? It's really kicking my butt. Thanks.
The problem is precisely what it tells you: you're not allowed to use new Story as the result of your query. Use an anonymous type instead (by omitting Story after new). If you still want Story, you can remap it later in LINQ to Objects:
var stories = from s in db.Stories
orderby s.DateEntered descending
select new
{
Title = s.Title,
StoryContent = s.StoryContent,
DateEntered = s.DateEntered,
DateUpdated = s.DateUpdated,
UserName = s.aspnet_User.UserName
};
stories = from s in stories.AsEnumerable() // L2O
select new Story
{
Title = s.Title,
StoryContent = s.StoryContent,
...
};
If you really need to return an IQueryable from your method and still need the Username of the user you can use DataContext.LoadOptions to eagerload your aspnet_user objects.
See this example.
i was looking at an example of how to do an insert in Linq to SQL and here it was it said:
NorthwindDataContext context = new NorthwindDataContext();
context.Products.Add(new Product(..));
context.SubmitChanges();
but when i look at the below, (in my case the Table is UserInfo), the Table doesn't have an "Add" method:
public System.Data.Linq.Table<UserInfo> UserInfos
{
get
{
return this.GetTable<UserInfo>();
}
}
any clue what i am doing wrong here?
You should use the InsertOnSubmit method:
NorthwindDataContext context = new NorthwindDataContext();
context.Products.InsertOnSubmit(new Product(..));
context.SubmitChanges();
The Add method exist on the EntitySet members, is mostly used when adding Child entities to a Parent one, for example:
var category = new Category{ Name = "Breveages"};
category.Products.Add(new Product{ Name = "Orange Juice"});
category.Products.Add(new Product{ Name = "Tomato Juice"});
category.Products.Add(new Product{ Name = "Cola"});
//...
context.Categories.InsertOnSubmit(category);
// This will insert the Category and
// the three Products we associated to.
EDIT: To do update operations, you just need to retrieve the entity by doing a query, or attaching it, for example:
var customer = context.Customers.Single( c => c.CustomerID == "ALFKI");
customer.ContactName = "New Contact Name";
context.SubmitChanges();
The DataContext tracks the changes of its related entities and when the SubmitChanges method is called, it will detect that change, and generate an Update SQL statement behind the scenes to do the update operation...