Is there a pre-built ModelBinder I can use with LINQ to get an object from a DataContext and update it on a HTTP post?
For example, currently I have this block of code:
[AcceptVerbs (HttpVerbs.Post)]
public ActionResult Edit (Project project)
{
var projectService = Factory.GetService<IProjectService> ();
project = projectService.GetProject (project.ProjectId);
UpdateModel<Project> (project);
if (!ModelState.IsValid)
return View (project);
project = projectService.SaveProject (project);
return RedirectToAction ("Details", new { id = project.ProjectId });
}
(IProjectService wraps up calls to a LINQ data context)
In order to actually perform the update to the database via the LINQ data context, I need to get the project instance again and then update that instance.
Any attempt to simply save the project instance without first getting it from the data context results in nothing being written back to the database - I'm assuming because the LINQ data context knows nothing of the object it doesn't do anything with it.
Using the Attach method on the Projects table class doesn't work either btw, it throws an exception.
You should look at the implementation in Mike Hadlow's (new BSD) SutekiShop.
In there you will find a DataBindAttribute and BindUsingAttribute which, if I understand correctly, do exactly what you want to do. Notice how the DataBindAttribute.Fetch property is used to rebind the incoming data, or not, (from an HttpPost) to a LINQ entity.
I followed this pattern for one of my projects using ASP.NET MVC and LINQ-To-SQL. It works beautifully.
Here's the source: http://www.google.com/codesearch?hl=en&lr=&q=DataBind+package%3Ahttp%3A%2F%2Fsutekishop.googlecode.com&sbtn=Search
I think the project you pass in to the method is the one you want to perform UpdateModel with isn't it?
Otherwise you are trying to update with pre-existing values not new ones.
Just a thought,
Dan
Code cut out below
[AcceptVerbs (HttpVerbs.Post)]
public ActionResult Edit (Project project)
UpdateModel<Project> (project);
if (!ModelState.IsValid)
return View (project);
var projectService = Factory.GetService<IProjectService> ();
project = projectService.SaveProject (project);
return RedirectToAction ("Details", new { id = project.ProjectId });
}
You need to retrieve the original project as you do then to update it with the properties that have changed in project to update then to submit the update request.
EDIT
Try this code I found:
public static void CloneProperties(this object origin, ref object destination)
{
if (destination == null) throw new ArgumentNullException("destination", "Destination object must first be instantiated.");
foreach (var destinationProperty in destination.GetType().GetProperties())
{
if (origin != null && destinationProperty.CanWrite)
{
origin.GetType().GetProperties().Where(x => x.CanRead && (x.Name == destinationProperty.Name && x.PropertyType == destinationProperty.PropertyType)) .ToList() .ForEach(x => destinationProperty.SetValue(destination, x.GetValue(origin, null), null));
}
}
}
Related
I am trying to add a new record in an MVC controller method using Entity framework.
When i just used "InsertOrUpdate" the audittype got duplicated. Based on the answer from Entity Framework adding record with a related object i hoped to fix it pretty qiock. This is the code I have right now:
Controller:
if (ModelState.IsValid)
{
Audit newAudit = Factory.GetNew();
newAudit.Name = model.Name;
newAudit.Deadline = model.Deadline;
newAudit.AuditType = auditTypeRepository.Find(model.SelectedAuditTypeId);
Repository.InsertOrUpdate(newAudit);
Repository.Save();
return RedirectToAction(MVC.Audits.Details(newAudit.Id));
}
Repository:
public override void InsertOrUpdate(Qdsa.WebApplications.AuditMaster.Data.Audit model)
{
if (model.Id == default(int))
{
// New entity
context.Audits.Add(model);
}
else
{
// Existing entity
model.ModifiedOn = DateTime.Now;
context.Entry(model).State = EntityState.Modified;
}
//If I leave out the code below the AuditType will be duplicated
if (model.AuditType != null)
{
context.Entry<AuditType>(model.AuditType).State = EntityState.Unchanged;
}
}
public virtual void Save()
{
context.SaveChanges();
}
So i thought I fixed the problem. However, AuditType has Child objects too. And now these childobjects get duplicated.
What is the right way to add entities with child objects which already exists?
Because the AuditType is required I can't save it without first and then update it. any suggestions?
UPDATE:
Both the AuditRepostory and the AuditTypeRepository inherit from BaseRepository which has the context as:
protected DBContext context = new DBContext ();
public virtual T Find(int id)
{
return All.SingleOrDefault(s => s.Id == id);
}
I can imagine two reasons for the problem:
Either auditTypeRepository.Find performs a no tracking query (with .AsNoTracking())
Or you are using a context instance per repository, so that Repository and auditTypeRepository are working with two different contexts which will indeed result in a duplication of the AuditType because you don't attach it to the the context that corresponds with Repository (except in the line with your comment).
If the latter is the case you should rethink your design and inject a single context instance into all repositories instead of creating it inside of the repositories.
I think the problem is from here:
newAudit.AuditType = auditTypeRepository.Find(model.SelectedAuditTypeId);
Change that like this:
newAudit.AuditTypeId = model.SelectedAuditTypeId;
I am beginner in breeze, I want to integrate it into an ASP.net MVC4 project .
I have the same problem in Saving Data Using Breeze.js
but this post did not answer the problem and I hope we can do it this time
The problem is that I don’t have to use Entity Framework and I don’t know how to replace ContextProvider in SaveChanges method in the controller
[HttpPost]
public SaveResult SaveChanges (JObject saveBundle) {
return ContextProvider.SaveChanges (saveBundle);
}
I also tried to customize ressourceName by using SaveOptions:
var option = new breeze.SaveOptions ({resourceName 'MyContoller'});
entityManager.saveChanges (null, optional)
. then (
alert ("ok");
)
. fail (function (e) {
alert (e);
});
When I run it no problem starts but the controller does not receive data!
So my question is:
How can I save changes with breeze without using EntityFramework?
Thank you in advance
To solve this problem I redefined savaChanges method to read the json data and assign it to my object, but I'm not sure that it is the right way:
This is my SaveChanges method
[HttpPost]
public void SaveChanges(JObject saveBundle)
{
JToken jMyObject = saveBundle["entities"];
MyClass myObject= new MyClass ();
string state=(string) jMyObject [0]["entityAspect"]["entityState"];
if (state == "Added")
{
myObject.name =
(string) jMyObject [0]["name"];
CreateEntity(myObject);
}
}
I am trying to move a record from one table into another matching (almost) table using EF5, MVC, and Automapper.
This code is what I am using:
In My Global Application_Start
//Create Map and manually map StatusCode to Status
Mapper.CreateMap<InstitutionStaging, InstitutionStaging_Archive>()
.ForMember(dest => dest.Status,o =>o.MapFrom(src=>src.StatusCode));
In my Controller
private MyContext db = new MyContext();
Public ActionResult ArchiveMe(int id = 0){
var institutionstaging = db.InstitutionStagings.Find(id);
if (institutionstaging == null)
{
return HttpNotFound();
}
if (ModelState.IsValid)
{
var institutionArchive = Mapper.Map<InstitutionStaging, InstitutionStaging_Archive>(institutionstaging);
//Set Archive date to now.
institutionArchive.ArchiveDate = DateTime.Now;
//Error happens on the next line
db.InstitutionStaging_Archives.Add(institutionArchive);
db.InstitutionStagings.Remove(institutionstaging);
db.Entry(institutionArchive).State = EntityState.Added;
//Commit the changes
var result = db.SaveChanges();
}
}
When it hits the line marked "Error happens here==>" I get the following error message.
{"The entity type InstitutionStaging_Archive is not part of the model for the current context."}
The MyContext contains DbSets for both InstitutionStaging and InstitutionStaging_Archive.
Any idea what is happening?
TIA
J
This error isn't typically a problem with AutoMapper, but rather a problem with your Entity Framework model setup.
It can be because you are using the wrong connection string, or it can be because you don't have the model mapped correctly.
Since we don't know what your model is, what your database looks like, or how your mappings are.. can't help much beyond that.
To prove it to yourself, just comment out the automapper stuff and do it by hand, and I'm pretty sure you'll get the same error.
When I update my model I get an error on a child relation which I also try to update.
My model, say Order has a releationship with OrderItem. In my view I have the details of the order together with an editortemplate for the orderitems. When I update the data the link to Order is null but the orderid is filled, so it should be able to link it, TryUpdateModel returns true, the save however fails with:
InvalidOperationException: The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.]
My update method:
public ActionResult ChangeOrder(Order model)
{
var order = this.orderRepository.GetOrder(model.OrderId);
if (ModelState.IsValid)
{
var success = this.TryUpdateModel(order);
}
this.orderRepository.Save();
return this.View(order);
}
I tried all solutions I saw on SO and other sources, none succeeded.
I use .Net MVC 3, EF 4.3.1 together with DBContext.
There are a number of code smells here, which I'll try to be elegant with when correcting :)
I can only assume that "Order" is your EF entity? If so, I would highly recommend keeping it separate from the view by creating a view model for your form and copying the data in to it. Your view model should really only contain properties that your form will be using or manipulating.
I also presume orderRepository.GetOrder() is a data layer call that retrieves an order from a data store?
You are also declaring potentially unused variables. "var order =" will be loaded even if your model is invalid, and "var success =" is never used.
TryUpdateModel and UpdateModel aren't very robust for real-world programming. I'm not entirely convinced they should be there at all, if I'm honest. I generally use a more abstracted approach, such as the service / factory pattern. It's more work, but gives you a lot more control.
In your case, I would recommend the following pattern. There's minimal abstraction, but it still gives you more control than using TryUpdateModel / UpdateModel:
public ActionResult ChangeOrder(OrderViewModel model) {
if(ModelState.IsValid) {
// Retrieve original order
var order = orderRepository.GetOrder(model.OrderId);
// Update primitive properties
order.Property1 = model.Property1;
order.Property2 = model.Property2;
order.Property3 = model.Property3;
order.Property4 = model.Property4;
// Update collections manually
order.Collection1 = model.Collection1.Select(x => new Collection1Item {
Prop1 = x.Prop1,
Prop2 = x.Prop2
});
try {
// Save to repository
orderRepository.SaveOrder(order);
} catch (Exception ex) {
ModelState.AddModelError("", ex.Message);
return View(model);
}
return RedirectToAction("SuccessAction");
}
return View(model);
}
Not ideal, but it should serve you a bit better...
I refer you to this post, which is similar.
I assume that the user can perform the following actions in your view:
Modify order (header) data
Delete an existing order item
Modify order item data
Add a new order item
To do a correct update of the changed object graph (order + list of order items) you need to deal with all four cases. TryUpdateModel won't be able to perform a correct update of the object graph in the database.
I write the following code directly using a context. You can abstract the use of the context away into your repository. Make sure that you use the same context instance in every repository that is involved in the following code.
public ActionResult ChangeOrder(Order model)
{
if (ModelState.IsValid)
{
// load the order from DB INCLUDING the current order items in the DB
var orderInDB = context.Orders.Include(o => o.OrderItems)
.Single(o => o.OrderId == model.OrderId);
// (1) Update modified order header properties
context.Entry(orderInDB).CurrentValues.SetValues(model);
// (2) Delete the order items from the DB
// that have been removed in the view
foreach (var item in orderInDB.OrderItems.ToList())
{
if (!model.OrderItems.Any(oi => oi.OrderItemId == item.OrderItemId))
context.OrderItems.Remove(item);
// Omitting this call "Remove from context/DB" causes
// the exception you are having
}
foreach (var item in model.OrderItems)
{
var orderItem = orderInDB.OrderItems
.SingleOrDefault(oi => oi.OrderItemId == item.OrderItemId);
if (orderItem != null)
{
// (3) Existing order item: Update modified item properties
context.Entry(orderItem).CurrentValues.SetValues(item);
}
else
{
// (4) New order item: Add it
orderInDB.OrderItems.Add(item);
}
}
context.SaveChanges();
return RedirectToAction("Index"); // or some other view
}
return View(model);
}
I'm having trouble trying to think what the best way is to recreate a database object in a controller Action.
I want to make use of ModelBinders so in my action I have access to the object via a parameter, rather than having to repeat code to get an object from the database based on an identifier parameter. So I was thinking of having a ModelBinder that performs a call to the dataaccess layer to obtain the original object (or creates a new one if it doesn't exist in the database), then binds any properties to the database object to update it. However I've read that the ModelBinders shouldn't make database queries (first comment of this article).
If the ModelBinder shouldn't perform a database query (so just using the DefaultModelBinder) then what about database objects that have properties that are other db objects? These would never get assigned.
Saving an object after the user has edited it (1 or 2 properties are editable in the view) the ModelBinded object would be missing data, so saving it as it is would result in data in the database being overwritten with invalid values, or NOT-NULL constraints failing.
So, whats the best way to get an object in a controller action from the database bound with the form data posted back from the view?
Note im using NHibernate.
I get the model object from the database, then use UpdateModel (or TryUpdateModel) on the object to update values from the form parameters.
public ActionResult Update( int id )
{
DataContext dc = new DataContext();
MyModel model = dc.MyModels.Where( m => m.ID == id ).SingleOrDefault();
string[] whitelist = new string[] { "Name", "Property1", "Property2" };
if (!TryUpdateModel( model, whitelist )) {
... model error handling...
return View("Edit");
}
ViewData.Model = model;
return View("Show");
}
Unfortunately you don't have control over the construction of the model binder, so you can't inject any repository implementation.
You can reach out directly into a service locator to pull in your repository & fetch the item:
public class ProductBinder : DefaultModelBinder
{
protected override object CreateModel(ControllerContext controllerContext,
ModelBindingContext bindingContext, Type modelType)
{
if(modelType != typeof(Product))
return null;
var form = controllerContext.HttpContext.Request.Form;
int id = Int32.Parse(form["Id"]);
if(id == 0)
return base.CreateModel(controllerContext, bindingContext, modelType);
IProductRepository repository = ServiceLocator.Resolve<IProductRepository>();
return repository.Fetch(id);
}
}
You might even make this work for all of your entities if you can use a base class or interface that provides the Id of the class.
You'll have to set this up in Global.asax:
ModelBinders.Binders.Add(typeof(Product), new ProductBinder());
and then you can do this:
public ActionResult Save([Bind] Product product)
{
....
_repository.Save(product);
}
Let me first state that I don't recommend to access database from ModelBinders, as from perspective of Separation Of Concern ModelBinders should only be responsible of interpretting client request, obviously database is not.
If you dont want to repeat your self (DRY), use repositories/services
However if u really want to do it like that, then
In global.asax.cs Register a custom MyModelBinderProvider to MVC
ModelBinderProviders.BinderProviders.Add(new EntityModelBinderProvider
{
ConnectionString = "my connection string"
));
Cunstruct the custom ModelBinderProvider to contain database settings
public class EntityBinderProvider: IModelBinderProvider
{
public string ConnectionString { get; set; }
public IModelBinder GetBinder(Type modelType)
{
if (Is known entity)
return new EntityBinder(ConnectionString);
else
return null;
}
}
Follow further instructions from Ben Scheirman
You don't actually have to hit the database. Simply setting the Id of the objects will be enough to set the relationship up, but watch your cascades. Make sure your cascde settings won't update the related object as it will clear the values.