I am working with a Spring MVC project and I can't figure out how to change the String representation of a Model in the Views.
I have a Customer model that has a ONE_TO_MANY relationship with a WorkOrder model. On the workorders/show.jspx the Customer is displayed as a String that is the first and last name, email address, and phone number concatenated.
How do I change this? I thought I could just change the toString method on the Customer, but that didn't work.
One solution would be to change/push-in show() to WorkOrderController to map a rendered-view-tag to what you would like to see.
#RequestMapping(value = "/{id}", produces = "text/html")
public String show(
#PathVariable("id") Long id,
Model uiModel)
{
final WorkOrder workOrder = WorkOrder.findWorkOrder(id);
uiModel.addAttribute("workOrder", workOrder);
uiModel.addAttribute("itemId", id);
// Everything but this next line is just ripped out from the aspectJ/roo stuff.
// Write a method that returns a formatted string for the customer name,
// and a customer accessor for WorkOrder.
uiModel.addAttribute("customerDisplay", workOrder.getCustomer().getDisplayName());
return "workorders/show";
}
Put/define a label in your i18n/application.properties file for customerDisplay.
Then in your show.jspx, you can access the mapping with something like... (The trick is similar for other views.)
<field:display field="customerDisplay" id="s_your_package_path_model_WorkOrder_customerDisplay" object="${workorder}" z="user-managed" />
I'm new to Roo, so I'd love to see a better answer.
We found a good solution. There are toString() methods for all the models in ApplicationConversionServiceFactoryBean_Roo_ConversionService.aj
You can just push the method for the Model you want into ApplicationConversionServiceFactoryBean.java and modify it. In my case I added this:
public Converter<Customer, String> getCustomerToStringConverter() {
return new org.springframework.core.convert.converter.Converter<com.eg.egmedia.bizapp.model.Customer, java.lang.String>() {
public String convert(Customer customer) {
return new StringBuilder().append(customer.getId()).append(' ').append(customer.getFirstName()).append(' ').append(customer.getLastName()).toString();
}
};
}
Spring uses this for all the view pages so this will change the String representation of your model across your whole app!
Related
i am confused about availibility from data within spring-model.
Example:
#RequestMapping("myAbosolutPathAAA.action")
public String myHandlerONE(#RequestParam(required = false) String date, Model model){
ArryList<Car> myCars = carsDAO.findAll(); //retrieve all cars from DB.
model.addAttribute(CARS, myCars);
return "page1.action";
}
Now i can handle my car-list on frontend.
At next i navigate on next controler-handler, where i need myCars-list again.
So i dont want to retrieve database anymore. I want to retrieve my spring-model:
#RequestMapping("myAbosolutPathBBB.action")
public String myHandlerTWO(#RequestParam String name, Model model){
ArryList<Car> myCars = model.asMap().get(CARS); //retrieve spring-model and not db .
//do somethings with car list....
return "page2.action";
}
But when i want to retrieve spring-model, my car-list is null.
Sometimes it works. I can not finde any explanation on spring-reference.
Can's anybody explain, when can i retrieve spring-model and when not?
I'm developing an MVC3 application and I have a page (well, a view) that let the users edit document's metainfo (a classic #Html.BeginForm usage). For general documents users will see standard fields to fill up, but through a dropdownlist they will be able to specify the type of the document: this, through an ajax call, will load new fields on the edit-document-form.
Whem the user submit the completed form, at last, the controller should read all the standard fields, plus all the fields loaded as being specific to the type of document selected.
Question is, how can I handle all this extra fields in a controller?
Say that I have Document class and a bunch of other classes extendinf Document, like Contract : Document, Invoice : Document, Complaint : Document and so forth, each having specific property (and this fields loaded on the form), how do I write the action in the controller?
I thought to use something like (I'll omitt all the conversions, validations, etc, for brevity)
[HttpPost]
public ActionResult Save(dynamic doc)
{
int docType = doc.type;
switch (docType)
{
case 1:
var invoice = new Invoice(doc);
invoice.amount = Request.Form["amount_field"];
invoice.code = Request.Form["code_field"];
//and so forth for every specific property of Invoice
Repository.Save(invoice);
break;
case 2:
var contract = new Contract(doc);
contract.fromDate = Request.Form["fromDate_field"];
contract.toDate = Request.Form["toDate_field"];
//and so forth for every specific property of Contract
Repository.Save(contract);
break;
..... // and so forth for any document types
default:
break;
}
}
But it seems a very dirty approach to me. Do you have a better idea on how to achive this? Maybe there's a pattern that I don't know nothing about to approach this kind of scenario.
Update
A second idea comes to my mind. After commenting Rob Kent's answer, I thought I could take a different approach, having just one class Document with a property like
public IEnumerable<Field> Tipologie { get; set; }
where
public class Field
{
public int IdField { get; set; }
public String Label { get; set; }
public String Value { get; set; }
public FieldType ValueType { get; set; }
public List<String> PossibleValues { get; set; } // needed for ENUMERATION type
}
public enum FieldType
{
STRING, INT, DECIMAL, DATE, ENUMERATION
}
Is this a better approach? In this case I can have just an action method like
[HttpPost]
public ActionResult Save(Document doc)
But shoud I create the fields in the view in order to make the MVC engine do the binding back to the model?
Given that the class inheriting from Document in the first approach will probably be generated at run-time, would you prefer this second approach?
To keep it all hard-typed on the server, you could use an abstract base type with a custom binder. See my answer here to see how this works: MVC generic ViewModel
The idea is that every time they load a new set of fields, you change the BindingType form variable to the instantiated type of the handler. The custom binder is responsible for creating the correct type on submission and you can then evaluate that in your action, eg:
if (model is Contract) ...
I'm not sure if you will be able to set up different actions each with a different signature, eg,:
public ActionResult Save(Contract contract) ...
public ActionResult Save(Invoice invoice) ...
Pretty sure that won't work because Mvc will have already decided which method to call, or maybe it will firstly see what type it gets back and then decides.
In my linked example, I am checking for overridden base members but if that is not an issue for you, you just need to create the correct type.
Earlier today, a helpful person (here on Stack Overflow) pointed me towards AutoMapper, I checked it out, and I liked it a lot! Now however I am a little stuck.
In my Code First MVC3 Application, on my [Home/Index] I need to display the following information from my Entities:
List of Posts [ int Id, string Body, int Likes, string p.User.FirstName, string p.User.LastName ]
List of Tags [int Id, string Name]
List of All Authors that exist on my Database [ string UrlFriendlyName ]
So far I have managed only point 1 in the list by doing the following for my Index ViewModel:
public class IndexVM
{
public int Id { get; set; }
public string Body { get; set; }
public int Likes { get; set; }
public string UserFirstName { get; set; }
public string UserLastName { get; set; }
}
And on the Home Controller, Index ActionMethod I have:
public ActionResult Index()
{
var Posts = postsRepository.Posts.ToList();
Mapper.CreateMap<Post, IndexVM>();
var IndexModel = Mapper.Map<List<Post>, List<IndexVM>>(Posts);
return View(IndexModel);
}
Finally on my View I have it strongly typed to:
#model IEnumerable<BlogWeb.ViewModels.IndexVM>
And I am passing each Item in the IndexVM IEnumberable to a Partial View via:
#foreach (var item in Model)
{
#Html.Partial("_PostDetails", item)
}
My question is, how can I also achieve point 2 and 3, whilst not breaking what I've achieved in point 1.
I tried putting the stuff I currently have for IndexVM into a SubClass, and having a List Property on the Parent class, but it didn't work.
From the ASP.NET MVC2 In Action Book:
Some screens are more complex than a single table. They may feature
multiple tables and additional fields of other data: images, headings,
subtotals, graphs, charts, and a million other things that complicate
a view. The presentation model solution scales to handle them all.
Developers can confidently maintain even the gnarliest screens as long
as the presentation model is designed well. If a screen does contain
multiple complex elements, a presentation model can be a wrapper,
composing them all and relieving the markup file of much complexity. A
good presentation model doesn’t hide this complexity—it represents it
accurately and as simply as possible, and it separates the data on a
screen from the display.
Make a ViewModel that represents your screen. Then build it up and pass it to the View. This book is great and talks about using a presentation model. With AutoMapper, think about how you would accomplish your mapping without it, then make use of it. AutoMapper isn't going to do anything magic, it eliminates keyboard slapping.
AutoMapper aside, take your list of requirments:
List of Posts [ int Id, string Body, int Likes, string p.User.FirstName, string p.User.LastName ]
List of Tags [int Id, string Name]
List of All Authors that exist on my Database [ string
UrlFriendlyName ]
and assuming you have these Model entites: Post, Tag, Author
Personally I don't like passing Model entities to my presentation in MVC or MVVM but that's me. Say we follow that here and create PostDisplay, TagDisplay, and AuthorDisplay.
Based on the View's requirements the ViewModel will look like this:
Public class IndexVM
{
Public List<PostDisplay> Posts {get; set;}
Public List<TagDisplay> Tags {get; set;}
Public List<AuthorDisplay> Authors {get; set;}
}
In this case the way the View is composed will require you to build it up:
public ActionResult Index()
{
var posts = postsRepository.Posts.ToList();
var tags = postsRepository.Tags.ToList();
var authors = postsRepository.Authors.ToList();
Mapper.CreateMap<Post, PostDisplay>();
Mapper.CreateMap<Tag, TagDisplay>();
Mapper.CreateMap<Author, AuthorDisplay>();
private var IndexVM = new IndexVM
{
Posts = Mapper.Map<List<Post>, List<PostDisplay>>(posts),
Tags = Mapper.Map<List<Tag>, List<TagDisplay>>(tags),
Authors = Mapper.Map<List<Author>, List<AuthorDisplay>>(authors)
};
return View(IndexVM);
}
So, what you end up with is a ViewModel to pass to your view that represents exactly what you want to display and isn't tightly coupled to your Domain Model. I can't think of a way to have AutoMapper map three separate result lists into one object.
To clarify, AutoMapper will map child collections so a structure like:
public class OrderItemDto{}
public class OrderDto
{
public List<OrderItemDto> OrderItems { get; set; }
}
will map to:
public class OrderItem{}
public class Order
{
public List<OrderItem> OrderItems { get; set; }
}
As long as you tell it how to map the types: OrderDto -> Order and OrderItemDto -> OrderItem.
As an alternative to including all of your lists of entities on a single viewmodel, you could use #Html.Action. Then, in your screen view:
#Html.Action("Index", "Posts")
#Html.Action("Index", "Tags")
#Html.Action("Index", "Authors")
This way, your Index / Screen view & model don't need to know about the other viewmodels. The partials are delivered by separate child action methods on separate controllers.
All of the automapper stuff still applies, but you would still map your entities to viewmodels individually. The difference is, instead of doing the mapping in HomeController.Index(), you would do it in PostsController.Index(), TagsController.Index(), and AuthorsController.Index().
Response to comment 1
public class IndexVM
{
// need not implement anything for Posts, Tags, or Authors
}
Then, implement 3 different methods on 3 different controllers. Here is one example for the PostsController. Follow the same pattern for TagsController and AuthorsController
// on PostsController
public PartialViewResult Index()
{
var posts = postsRepository.Posts.ToList();
// as mentioned, should do this in bootstrapper, not action method
Mapper.CreateMap<Post, PostModel>();
// automapper2 doesn't need source type in generic args
var postModels = Mapper.Map<List<PostModel>>(posts);
return PartialView(postModels);
}
You will have to create a corresponding partial view for this, strongly-typed as #model IEnumerable<BlogWeb.ViewModels.PostModel>. In that view, put the HTML that renders the Posts UI (move from your HomeController.Index view).
On your HomeController, just do this:
public ActionResult Index()
{
return View(new IndexVM);
}
Keep your view strongly-typed on the IndexVM
#model IEnumerable<BlogWeb.ViewModels.IndexVM>
... and then get the Posts, Tags, and Authors like so:
#Html.Action("Index", "Posts")
Response to comment 2
Bootstrapping... your Mapper.CreateMap configurations only have to happen once per app domain. This means you should do all of your CreateMap calls from Application_Start. Putting them in the controller code just creates unnecessary overhead. Sure, the maps need to be created - but not during each request.
This also helps with unit testing. If you put all of your Mapper.CreateMap calls into a single static method, you can call that method from a unit test method as well as from Global.asax Application_Start. Then in the unit test, one method can test that your CreateMap calls are set up correctly:
AutoMapperBootStrapper.CreateAllMaps();
Mapper.AssertConfigurationIsValid();
I have a big object that I resorted to serializing using #Html.Serialize():
[Serializable]
public class ModelB
{
public List<ModelA> ListOfModelA { get; set; }
// more stuff
}
This object contains a list of objects from a class that contains several properties. Some of them I include them in my view, while other I do not even bother to put them as hidden fields, as I have them in my serialized model.
[Serializable]
public class ModelA
{
public string StringA { get; set; }
public string StringB { get; set; }
// more stuff
public string HiddenStringA { get; set; }
public string HiddenStringB { get; set; }
// more stuff
}
Now, when I post back the form with my changes I reconstract my model and then I update it using the dictionary of values obtained from the form.
[HttpPost]
public ActionResult Edit([Deserialize] ModelTwo model,
FormCollection form)
{
TryUpdateModel(model, form.ToValueProvider());
// more stuff
}
I step in my code and just before I do the update, I see that my deserialized model contains a list ListOfModelA that in turn contains all the elements that should be there, and within them I can see all the HiddenStringA and HiddenStringB properties. Then I peek inside the form and I see a dictionary with keys like these:
ListOfModelA[0].StringA
ListOfModelA[0].StringB
ListOfModelA[1].StringB
ListOfModelA[1].StringB
while there are NO keys for the rest of the properties like this one:
ListOfModelA[0].HiddenStringA
Next, I move one step further and I let the code do the TryUpdateModel. Now, looking inside the ListOfModelA property, all the elements have been replaced with new ones that have all the hidden values null. It is as if the update reconstructed whole elements (with the limited information it had), rather than updating only the properties for which it had information.
Is this the expected behaviour? Is there a way to keep my model, and update only the properties that have keys in the dictionary?
Thanks,
Panos
My problem is more complex than the one described above, but the solultion that I found for the specific design is along the following lines. I serialize the part of the model that is a list, and bind the whole model through an argument of the action. This way I avoid using the TryUpdateModel, although this is not what causes me the trouble. Then, I inject the non-null values into the deserialized model from the model created from the form, and lastly I point the corresponding part of the latter to the former.
[HttpPost]
public ActionResult Edit(ModelTwo model,
[Deserialize] List<ModelA> serializedList)
{
serializedList.InjectFrom<NonNullLoopValueInjection>(model.ListOfModelA);
model.ListOfModelA = serializedList;
// more stuff
}
For the injection, I use Value Injecter where NonNullLoopValueInection is defined below
public class NonNullLoopValueInjection : LoopValueInjection
{
protected override bool AllowSetValue(object value)
{
return value != null;
}
}
Maybe not the best design, but it is working, and it might lead me to something better. Any feedback is more than welcome.
Hi there I am hoping someone can point me in the right direction.
I want to create an mvc applicaton I have worked my way through the music store example and still am not 100% sure the correct way to do things.
Lets say I want to create an application that stores cooking receipes.
I have a 3 tables
RecipeTable
RecipeID
RecipeName
RecipeIngredients
RecipeIngredientID
RecipeID
IngredientID
Measurement
IngredientTable
IngredientID
IngredientName
All have PK & FK mappings very basic, I create a new mvc application and use the entity framework to create a new entity e.g. RecipeDB
My next step is I create a new model for each of the tables and give the properties my desired displaynames and specify required fields extra.
Do I then create a viewmodel e.g. RecipesViewModel that looks something like
public class RecipesViewModel
{
public int RecipeID { get; set; }
public string RecipeName { get; set; }
public List<RecipeIngredients> { get; set; }
}
I now create the controller (Ithink) but I am not really sure how to bind that to database entity.
I know you can call the database by doing something like RecipeEntities db = new recipeEntites(); however binding the results to the vm I am little confussed on how to do that.
Am I heading in the right direction so far?
You could use AutoMapper. It's a great tool allowing you to convert from one type to another and in your case from the model to the view model.
public ActionResult Foo()
{
RecipeDB model = _repository.GetRecipies();
RecipesViewModel viewModel = Mapper.Map<RecipeDB, RecipesViewModel>(model);
return View(viewModel);
}
or you could even define a custom action attribute (like the one I used in my sample MVC project) allowing you to simply write:
[AutoMap(typeof(RecipeDB), typeof(RecipesViewModel))]
public ActionResult Foo()
{
RecipeDB model = _repository.GetRecipies();
return View(model);
}