I'm looking for someone to point me in the right direction (link) or provide a code example for implementing a drop down list for a many-to-one relationship using RequestFactory and the Editor framework in GWT. One of the models for my project has a many to one relationship:
#Entity
public class Book {
#ManyToOne
private Author author;
}
When I build the view to add/edit a book, I want to show a drop down list that can be used to choose which author wrote the book. How can this be done with the Editor framework?
For the drop-down list, you need a ValueListBox<AuthorProxy>, and it happens to be an editor of AuthorProxy, so all is well. But you then need to populate the list (setAcceptableValues), so you'll likely have to make a request to your server to load the list of authors.
Beware the setAcceptableValues automatically adds the current value (returned by getValue, and defaults to null) to the list (and setValue automatically adds the value to the list of acceptable values too if needed), so make sure you pass null as an acceptable value, or you call setValue with a value from the list before calling setAcceptableValues.
I know it's an old question but here's my two cents anyway.
I had some trouble with a similar scenario. The problem is that the acceptable values (AuthorProxy instances) were retrieved in a RequestContext different than the one the BookEditor used to edit a BookProxy.
The result is that the current AuthorProxy was always repeated in the ValueListBoxwhen I tried to edit a BookProxy object. After some research I found this post in the GWT Google group, where Thomas explained that
"EntityProxy#equals() actually compares their request-context and stableId()."
So, as I could not change my editing workflow, I chose to change the way the ValueListBox handled its values by setting a custom ProvidesKey that used a different object field in its comparison process.
My final solution is similar to this:
#UiFactory
#Ignore
ValueListBox<AuthorProxy> createValueListBox ()
{
return new ValueListBox<AuthorProxy>(new Renderer<AuthorProxy>()
{
...
}, new ProvidesKey<AuthorProxy>()
{
#Override
public Object getKey (AuthorProxy author)
{
return (author != null && author.getId() != null) ? author.getId() : Long.MIN_VALUE;
}
});
}
This solution seems ok to me. I hope it helps someone else.
Related
I'm new at Apache Isis and I'm stuck.
I want to create my own submit form with editable parameters for search some entities and a grid with search results below.
Firstly, I created #DomainObject(nature=Nature.VIEW_MODEL) with search results collection, parameters for search and #Action for search.
After deeper research, I found out strict implementations for actions (For exapmle ActionParametersFormPanel). Can I use #Action and edit #DomainObject properties(my search parameters for action) without prompts?
Can I implement it by layout.xml?
Then I tried to change a component as described here: 6.2 Replacing page elements, but I was confused which ComponentType and IModel should I use, maybe ComponentType.PARAMETERS and ActionModel or implement my own IModel for my case.
Should I implement my own Wicket page for search and register it by PageClassList interface, as described here: 6.3 Custom pages
As I understood I need to replace page class for one of PageType, but which one should I change?
So, the question is how to implement such issues properly? Which way should I choose?
Thank you!
===================== UPDATE ===================
I've implemented HomePageViewModel in this way:
#DomainObject(
nature = Nature.VIEW_MODEL,
objectType = "homepage.HomePageViewModel"
)
#Setter #Getter
public class HomePageViewModel {
private String id;
private String type;
public TranslatableString title() {
return TranslatableString.tr("My custom search");
}
public List<SimpleObject> getObjects() {
return simpleObjectRepository.listAll();
}
#Action
public HomePageViewModel search(
#ParameterLayout(named = "Id")
String id,
#ParameterLayout(named = "Type")
String type
){
setId(id);
setType(type);
// finding objects by entered parameters is not implemented yet
return this;
}
#javax.inject.Inject
SimpleObjectRepository simpleObjectRepository;
}
And it works in this way:
I want to implement a built-in-ViewModel action with parameters without any dialog windows, smth like this:
1) Is it possible to create smth like ActionParametersFormPanel based on ComponentType.PARAMETERS and ActionModel and use this component as #Action in my ViewModel?
2) Or I should use, as you said, ComponentType.COLLECTION_CONTENTS? As I inderstand my search result grid and my search input panel will be like ONE my stub component?
Thank you.
We have a JIRA ticket in our JIRA to implement a filterable/searchable component, but it hasn't yet made it to the top of the list for implementation.
As an alternative, you could have a view model that provides the parameters you want to filter on as properties, with a table underneath. (I see you asked another question here on SO re properties on view models, so perhaps you are moving in that direction also... I've answered that question).
If you do want to have a stab at implementing that ticket, then the ComponentTYpe to use is COLLECTION_CONTENTS. If you take a look at the isisaddons, eg for excel or gmap3 then it might help get you started.
======= UPDATE TO ANSWER (based on update made to query) ==========
I have some good news for you. v1.15.0-SNAPSHOT, which should be released in the couple of weeks, has support for "inline prompts". You should find these give a user experience very similar to what you are after, with no further work needed on your part.
To try it out, check out the current trunk, and then load the simpleapp (in examples/application/simpleapp). You should see that editing properties and invoking actions uses the new inline prompt style.
HTH
Dan
My question is this: How can you implement a default server-side "filter" for a navigation property?
In our application we seldom actually delete anything from the database. Instead, we implement "soft deletes" where each table has a Deleted bit column. If this column is true the record has been "deleted". If it is false, it has not.
This allows us to easily "undelete" records accidentally deleted by the client.
Our current ASP.NET Web API returns only "undeleted" records by default, unless a deleted argument is sent as true from the client. The idea is that the consumer of the service doesn't have to worry about specifying that they only want undeleted items.
Implementing this same functionality in Breeze is quite simple, at least for base entities. For example, here would be the implementation of the classic Todo's example, adding a "Deleted" bit field:
// Note: Will show only undeleted items by default unless you explicitly pass deleted = true.
[HttpGet]
public IQueryable<BreezeSampleTodoItem> Todos(bool deleted = false) {
return _contextProvider.Context.Todos.Where(td => td.Deleted == deleted);
}
On the client, all we need to do is...
var query = breeze.EntityQuery.from("Todos");
...to get all undeleted Todos, or...
var query = breeze.EntityQuery.from("Todos").withParameters({deleted: true})
...to get all deleted Todos.
But let's say that a BreezeSampleTodoItem has a child collection for the tools that are needed to complete that Todo. We'll call this "Tools". Tools also implements soft deletes. When we perform a query that uses expand to get a Todo with its Tools, it will return all Tools - "deleted" or not.
But how can I filter out these records by default when Todo.Tools is expanded?
It has occurred to me to have separate Web API methods for each item that may need expanded, for example:
[HttpGet]
public IQueryable<Todo> TodoAndTools(bool deletedTodos = false, bool deletedTools = false)
{
return // ...Code to get filtered Todos with filtered Tools
}
I found some example code of how to do this in another SO post, but it requires hand-coding each property of Todo. The code from the above-mentioned post also returns a List, not an IQueryable. Furthermore this requires methods to be added for every possible expansion which isn't cool.
Essentially what I'm looking for is some way to define a piece of code that gets called whenever Todos is queried, and another for whenever Tools is queried - preferably being able to pass an argument that defines if it should return Deleted items. This could be anywhere on the server-side stack - be it in the Web API method, itself, or maybe part of Entity Framework (note that filtering Include extensions is not supported in EF.)
Breeze cannot do exactly what you are asking for right now, although we have discussed the idea of allowing the filtering of "expands", but we really need more feedback as to whether the community would find this useful. Please add this to the breeze User Voice and vote for it. We take these suggestions very seriously.
Moreover, as you point out, EF does not support this.
But... what you can do is use a projection instead of an expand to do something very similar:
public IQueryable<Object> TodoAndTools(bool deleted = false
,bool deletedTools = false) {
var baseQuery = _contextProvider.Context.Todos.Where(td => td.Deleted == deleted);
return baseQuery.Select(t => new {
Todo: t,
Tools: t.Tools.Where( tool => tool.Deleted = deletedTools);
});
}
Several things to note here:
1) We are returning an IQueryable of Object instead of IQueryable of ToDo
2) Breeze will inspect the returned payload and automatically create breeze entities for any 'entityTypes' returned (even within a projection). So the result of this query will be an array of javascript objects each with two properties; 'ToDo' and 'Tools' where Tools is an array of 'Tool' entities. The nice thing is that both ToDo and Tool entities returned within the projection will be 'full' breeze entities.
3) You can still pass client side filters based on the projected property names. i.e.
var query = EntityQuery.from("TodoAndTools")
.where("Todo.Description", "startsWith", "A")
.using(em);
4) EF does support this.
I'm looking specifically for a way to automatically hyphenate CamelCase actions and views. That is, I'm hoping I don't have to actually rename my views or add decorators to every ActionResult in the site.
So far, I've been using routes.MapRouteLowercase, as shown here. That works pretty well for the lowercase aspect of URL structure, but not hyphens. So I recently started playing with Canonicalize (install via NuGet), but it also doesn't have anything for hyphens yet.
I was trying...
routes.Canonicalize().NoWww().Pattern("([a-z0-9])([A-Z])", "$1-$2").Lowercase().NoTrailingSlash();
My regular expression definitely works the way I want it to as far as restructuring the URL properly, but those URLs aren't identified, of course. The file is still ChangePassword.cshtml, for example, so /account/change-password isn't going to point to that.
BTW, I'm still a bit rusty with .NET MVC. I haven't used it for a couple years and not since v2.0.
This might be a tad bit messy, but if you created a custom HttpHandler and RouteHandler then that should prevent you from having to rename all of your views and actions. Your handler could strip the hyphen from the requested action, which would change "change-password" to changepassword, rendering the ChangePassword action.
The code is shortened for brevity, but the important bits are there.
public void ProcessRequest(HttpContext context)
{
string controllerId = this.requestContext.RouteData.GetRequiredString("controller");
string view = this.requestContext.RouteData.GetRequiredString("action");
view = view.Replace("-", "");
this.requestContext.RouteData.Values["action"] = view;
IController controller = null;
IControllerFactory factory = null;
try
{
factory = ControllerBuilder.Current.GetControllerFactory();
controller = factory.CreateController(this.requestContext, controllerId);
if (controller != null)
{
controller.Execute(this.requestContext);
}
}
finally
{
factory.ReleaseController(controller);
}
}
I don't know if I implemented it the best way or not, that's just more or less taken from the first sample I came across. I tested the code myself so this does render the correct action/view and should do the trick.
I've developed an open source NuGet library for this problem which implicitly converts EveryMvc/Url to every-mvc/url.
Uppercase urls are problematic because cookie paths are case-sensitive, most of the internet is actually case-sensitive while Microsoft technologies treats urls as case-insensitive. (More on my blog post)
NuGet Package: https://www.nuget.org/packages/LowercaseDashedRoute/
To install it, simply open the NuGet window in the Visual Studio by right clicking the Project and selecting NuGet Package Manager, and on the "Online" tab type "Lowercase Dashed Route", and it should pop up.
Alternatively, you can run this code in the Package Manager Console:
Install-Package LowercaseDashedRoute
After that you should open App_Start/RouteConfig.cs and comment out existing route.MapRoute(...) call and add this instead:
routes.Add(new LowercaseDashedRoute("{controller}/{action}/{id}",
new RouteValueDictionary(
new { controller = "Home", action = "Index", id = UrlParameter.Optional }),
new DashedRouteHandler()
)
);
That's it. All the urls are lowercase, dashed, and converted implicitly without you doing anything more.
Open Source Project Url: https://github.com/AtaS/lowercase-dashed-route
Have you tried working with the URL Rewrite package? I think it pretty much what you are looking for.
http://www.iis.net/download/urlrewrite
Hanselman has a great example herE:
http://www.hanselman.com/blog/ASPNETMVCAndTheNewIIS7RewriteModule.aspx
Also, why don't you download something like ReSharper or CodeRush, and use it to refactor the Action and Route names? It's REALLY easy, and very safe.
It would time well spent, and much less time overall to fix your routing/action naming conventions with an hour of refactoring than all the hours you've already spent trying to alter the routing conventions to your needs.
Just a thought.
I tried the solution in the accepted answer above: Using the Canonicalize Pattern url strategy, and then also adding a custom IRouteHandler which then returns a custom IHttpHandler. It mostly worked. Here's one caveat I found:
With the typical {controller}/{action}/{id} default route, a controller named CatalogController, and an action method inside it as follows:
ActionResult QuickSelect(string id){ /*do some things, access the 'id' parameter*/ }
I noticed that requests to "/catalog/quick-select/1234" worked perfectly, but requests to /catalog/quick-select?id=1234 were 500'ing because once the action method was called as a result of controller.Execute(), the id parameter was null inside of the action method.
I do not know exactly why this is, but the behavior was as if MVC was not looking at the query string for values during model binding. So something about the ProcessRequest implementation in the accepted answer was screwing up the normal model binding process, or at least the query string value provider.
This is a deal breaker, so I took a look at default MVC IHttpHandler (yay open source!): http://aspnetwebstack.codeplex.com/SourceControl/latest#src/System.Web.Mvc/MvcHandler.cs
I will not pretend that I grok'ed it in its entirety, but clearly, it's doing ALOT more in its implementation of ProcessRequest than what is going on in the accepted answer.
So, if all we really need to do is strip dashes from our incoming route data so that MVC can find our controllers/actions, why do we need to implement a whole stinking IHttpHandler? We don't! Simply rip out the dashes in the GetHttpHandler method of DashedRouteHandler and pass the requestContext along to the out of the box MvcHandler so it can do its 252 lines of magic, and your route handler doesn't have to return a second rate IHttpHandler.
tl:dr; - Here's what I did:
public class DashedRouteHandler : IRouteHandler
{
public IHttpHandler GetHttpHandler(RequestContext requestContext)
{
requestContext.RouteData.Values["action"] = requestContext.RouteData.GetRequiredString("action").Replace("-", "");
requestContext.RouteData.Values["controller"] = requestContext.RouteData.GetRequiredString("controller").Replace("-", "");
return new MvcHandler(requestContext);
}
}
This is my first post here, so I hope everything is fine.
Here is my problem:
I have a table in my database called UserTypes. It has:
ID;
IsPrivate;
Parent_ID;
The relevant ones are the first and the third one.
I have another table called UserTypes_T which has information for the different types, that is language specific. The fields are:
Language_ID;
UserType_ID;
Name;
What I'm trying to achieve is load the entire hierarchy from the UserTypes table and show it in a TreeView (this is not relevant for now). Then, by selecting some of the user types I can edit them in separate edit box (the name) and a combo box (the parent).
Everything works fine until I try to persist the changes in the database. EF has generated for me two entity classes for those tables:
The class for the user types has:
ID;
IsPrivate;
Parent_ID;
A navigational property for the self-reference (0..1);
A navigational property for the child elements;
Another navigational property for the UserTypes_T table (1..*);
The class for the translated information has:
UserType_ID;
Language_ID;
Name;
A navigational property to the UserTypes table (*..1);
A navigational property to the Languages table (*..1);
I get the data I need using:
return context.UserTypes.Include("UserTypes_T").Where(ut => ut.IsPrivate==false).ToList();
in my WCF Web service. I can add new user types with no problems, but when I try to update the old ones, some strange things happen.
If I update a root element (Parent_ID==null) everything works!
If I update an element where Parent_ID!=null I get the following error:
AcceptChanges cannot continue because the object’s key values conflict with another object in the ObjectStateManager.
I searched all over the internet and read the blog post from Diego B Vega (and many more) but my problem is different. When I change a parent user type, I actually change the Parent_ID property, not the navigational property. I always try to work with the IDs, not the generated navigational properties in order to avoid problems.
I did a little research, tried to see what is the object graph that I get and saw that there were lots of duplicate entities:
The root element had a list of its child elements. Each child element had a back reference to the root or to its parent and so on. You can imagine. As I wasn't using those navigational properties, because I used the IDs to get/set the data I needed, I deleted them from the model. To be specific I deleted points 4 and 5 from the UserTypes entity class. Then I had an object graph with each element only once. I tried a new update but I had the same problem:
The root element was updated fine, but the elements, that had some parents, threw the same exception.
I saw that I had a navigational property in the UserTypes_T entity class, pointing to a user type, so I deleted it too. Then this error disappeared. All the items in the object graph were unique. But the problem remained - I could update my root element with no problems, but when trying to update the children (with no exclusions) I got a null reference exception in the generated Model.Context.Extensions class:
if (!context.ObjectStateManager.TryGetObjectStateEntry(entityInSet.Item2, out entry))
{
context.AddObject(entityInSet.Item1, entityInSet.Item2);//here!
}
I tried to update only the name (which is in UserTypes_T) but the error is the same.
I'm out of ideas and I've been trying to solve this problem for 8 hours now, so I'll appreciate if someone gives me ideas or share their experience.
PS:
The only way I succeeded updating a child object was using the following code to retrieve the data:
var userTypes = argoContext.UserTypes.Include("UserTypes_T").Where(ut => ut.IsPrivate==false).ToList();
foreach (UserType ut in userTypes)
{
ut.UserType1 = null;
ut.UserTypes1 = null;
}
return userTypes;
where UserType1 is the navigational property, pointing to the parent user type and UserTypes1 is the navigational property, holding a list of the child element. The problem here was that EF "fixups" the objects and changes the Parent_ID to null. If I set it back again, EF sets the UserTypes1, too... Maybe there is a way to stop this behavior?
OK everybody, I just found what the problem was and I'm posting the answer if anybody else encounters the same issue.
The problem was that I was making some validation on the server in order to see if there isn't a circular reference between the user types. So, my method on the server looked something like:
using (MyEntities context = new MyEntities())
{
string errMsg = MyValidator.ValidateSomething(context.UserTypes,...);
if (!string.IsNullOrEmpty(errMsg)) throw new FaultException(errMsg);
//some other code here...
context.UserTypes.ApplyChanges(_userType);//_userType is the one that is updated
context.UserTypes.SaveChanges();
}
The problem is that when making the validation, the context is filled and when trying to save the changes, there are objects with the same key values.
The solution is simple - to use different context for validating things on the server:
using (MyEntities validationContext = new MyEntities())
{
//validation goes here...
}
using (MyEntities context = new MyEntities())
{
//saving changes and other processing...
}
Another one can be:
using (MyEntities context = new MyEntities())
{
using (MyEntities validationContext = new MyEntities())
{
//validation
}
//saving changes and other processing...
}
That's it! I hope it can be useful to somebody!
I'm using Entity Framework 4 and a Dynamic Data site to expose a bare-bones admin interface to a few users. Working pretty well in general, but I have run into this one problem on a couple of fields on my model.
Several tables have some audit-related fields - CreatedBy, CreatedDate, ModifiedBy, and ModifiedDate. These fields are required in the database and the associated models are marking the properties as non-nullable (all as it should be). However I am handing setting the values for these fields in code - the field templates for the field types mark these specific fields as disabled on the page, and in the SavingChanges event I set these fields to the appropriate values. All works great when I'm updating an existing item.
The problem comes in when I try to create a new item. I want these fields to remain empty on the page and be auto-populated by my code when submitted, but the Field Templates set up RequiredFieldValidators for these fields and won't let me submit them without a value. Normally this would be great, except that I want to prevent EF from validating these fields at the point of page submission.
I realize that I could mark the fields as nullable in the database and that would resolve the issue - it would probably even be just fine from the data standpoint, but I'm not comfortable with doing so - for one thing it's not unlikely that some of the models these fields appear on will be bulk loaded, possibly by someone else, at a later date. I would rather still have the database enforce the non-nullability of these fields. In the field templates I've tried moving the built-in SetUpValidator() call for the RequiredFieldValidator not to run when these specific fields are being loaded, and I've also tried disabling the RequiredFieldValidators and forcing their IsValid property to true. None of these actions allows me to submit the page.
Is there a way to tell EF/Dynamic Data to skip the validation for some fields?
EDIT
As noted below, I also tried marking them nullable in the model and not in the database, which caused an error: Problem in mapping fragments...Non-nullable column...in table...is mapped to a nullable entity property.
EDIT #2
I have found a solution that works, but requires modifying the auto-generated designer file for the entity set, which is fragile at best. I would love to know a "righter" way to do it, but if nothing becomes apparent in the next couple of days I'll post my own answer.
So here are the edits I found I had to make. When allowing the tool to create the entities in the edmx Designer.cs file I get properties like these:
for a datetime on the server side
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]
[DataMemberAttribute()]
public global::System.DateTime CreatedDate
{
get
{
return _CreatedDate;
}
set
{
OnCreatedDateChanging(value);
ReportPropertyChanging("CreatedDate");
_CreatedDate = StructuralObject.SetValidValue(value);
ReportPropertyChanged("CreatedDate");
OnCreatedDateChanged();
}
}
for a varchar
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]
[DataMemberAttribute()]
public global::System.String CreatedBy
{
get
{
return _CreatedBy;
}
set
{
OnCreatedByChanging(value);
ReportPropertyChanging("CreatedBy");
_CreatedBy = StructuralObject.SetValidValue(value, false);
ReportPropertyChanged("CreatedBy");
OnCreatedByChanged();
}
}
To make it work without validation for a DateTime property setting the IsNullable parameter of the EdmScalarPropertyAttribute to true is sufficient to avoid the issue. For the String property you also have to change the 2nd parameter of the SetValidValue method call to "true."
All of this said, the only reason that I'm leaving this as it is is because I don't expect to have to regenerated the entities more than once or twice before we move to a different platform for this site. And in this case, merging the version in I have checked in to git with the version generated by the tool allows me to avoid most of the headaches,
Here is my meta information for a read-only auto generated date field. I don't get validation controls validating these fields. Hope this helps.
[ReadOnly(true)]
[DataType(DataType.Date)]
[Column(IsDbGenerated = true, UpdateCheck = UpdateCheck.Never, AutoSync = AutoSync.Never)]
[UIHint("DateTime")]
[Display(Name = "Modified", Order = 1000)]
[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:d}")]
public object DateModified { get; private set; }