I'm modelling a very basic association between courses (CoursePage) and instances of that course (CourseInstance extending from DataObject):
class CoursePage extends Page {
public static $has_many = array('Instances' => 'CourseInstance');
}
class CourseInstance extends DataObject {
public static $has_one = array('Course' => 'CoursePage');
}
What I want in the CMS is a simple way to add course instances to the course page. The HasManyComplexDataField is working but means that all course pages have the same (long!) list of instances shared across all courses. What I want is a way to add / remove / edit just instances relating to that course, without any details of instances from any other CoursePage.
Is there a more simple field more suited to my needs? Alternatively, is there any way I can limit the complex field to only show related instances but also allow me to add new ones?
Setting the sourceFilter parameter of the HasManyComplexDataField to the following works:
'CourseID = ' . $this-ID
Related
Context
I have a custom Event Entity which has several child Entities: Problem and Maintenance (and few others but those two should be enough to describe the problem) entity classes inherit from Event entity class.
The addAction(), seeAction() and modifyAction() of ProblemController and MaintenanceController are (obviously) very similar but with some differences.
I want to have a button to display the see view of an Event, no matter if it is a Problem or a Maintenance. Same for modify.
For the add action it is a bit different: the user has to say (by clicking on child-specific button) what kind of child he want to add.
How I handle this so far
In my seeAction() and modifyAction(), I just forward the "call" depending on the type of the child:
public function seeAction(Event $event)
{
if($event instanceof \Acme\EventBundle\Entity\Problem){
return $this->forward('AcmeEventBundle:Problem:see', array('event_id' => $event->getId()));
}
elseif($event instanceof \Acme\EventBundle\Entity\Maintenance){
return $this->forward('AcmeEventBundle:Maintenance:see', array('maintenance_id' => $event->getId()));
}
}
I have no Event::addAction() but I have a Event::addCommon() which gathers the common parts of the addAction of Problem and Maintenance. Then I call this Event::addCommon() with Controller inheritance.
class ProblemController extends EventController
{
public function addAction(MeasurementSite $measurementSite)
{
$problem = new Problem();
$problem->setMeasurementSite($measurementSite);
$form = $this->createForm(new ProblemType($measurementSite), $problem);
$response = parent::addCommon($problem, $form);
return $response;
}
Problem
All this looks pretty ugly to me. If I want to share common things between Problem::seeAction() and Maintenance::seeAction(), I will have to call an Event function, but Event already forwarded something!! Information jumps from Parent to Child and vice versa...
I would like to know what is the proper way to manage this problem?
I looked a bit at setting Controller as a service, using PHP Traits, Routing inheritance but I couldn't extract anything clear and clean from this research...
I can see how you might end up chasing your tail on this sort of problem.
Instead of multiple controllers, consider have one EventController for all the routes along with individual ProblemHelper and MaintainenceHelper objects. The helper objects would have your add/see/modify methods and could extend a CommonHelper class.
Your controller would check the entity type, instantiate the helper and pass control over to it.
I have list of "skills" that I want a user to be able to go through, selecting appropriate levels from the list. So Skill looks something like this:
public class Skill
{
public String SkillName { get; set; }
public SkillLevel CurrentSkillLevel { get; set; }
public Boolean IsRequired { get; set; }
public Skill(String Name)
{
this.SkillName = Name;
this.IsRequired = true;
this.CurrentSkillLevel = SkillLevel.None;
}
}
There could be hundreds of skills - and the exact number is unknown at the moment, and certainly it needs to be dynamic, so I don't want to make the user go through the process of clicking on each skill, filling out the form, and submitting each time. I'd like to display all of the skills in the same page (one row each), allow the user to select all the values, then click submit once at the end.
Unfortunately, I've not had any experience with using MVC for anything other than singleton creation. I would normally use a separate ViewModel for several models bundled together, but I don't see how that would work with a dynamic list, and since they are all the same type ("Skill"), I guess the ViewModel would look exactly like a list of the model.
Does anyone have an appropriate solution?
Thanks
Building on DaveA's answer, you can use an editor template for Skill. You will need to add a folder named EditorTemplates to your Views\Controller folder. Now make a partial view in that folder named Skill.cshtml that looks something like this
#model Skill
#Html.TextBoxFor(s => s.SkillName)
#Html.TextBoxFor(s => s.Skills[i].Title)
// etc...
Now in your main view
using (Html.BeginForm("UpdateCart", "Orders"))
{
#Html.TextBoxFor(p=>p.Name)
#Html.TextBoxFor(p=>p.Title)
#Html.EditorFor(p => p.Skills)
}
Razor is smart enough that it will render each skill in Skills using the Skill.cshtml editor template.
I have a website that reads some of its content from a database, I need this website in both languages, English and Arabic.
the needed content is duplicated in the database in both languages. lets say I have a En_Name and Ar_Name columns in my database.
and for example for the Arabic version of the website a link will display a text from Ar_Name , and with the English one it should display the text from the En_Name.
for the static content in my website I think it is a good idea to use the ASP.NET default localization using (.resx files). but what I don't know is how to do the localization for the dynamic section of the website.
So, how can I make the same hyperlink read once from the Ar_Name field, and then from the En_Name based on the users choice (Localization)?
There are many ways to accomplish this. You've not mentioned which database technology you are using, so my example is with Entity Framework. You may need to customise this to your own situation.
Something similar may be possible with LinqToSql or other ORMs. If you are using something else entirely, then the key is to have a central class that you pass something consistent to (hence the interface) that does the translation.
For example, if I was using Entity Framework, every table in the database that had these two fields I'd add an interface that exposes those fields. Then I'd have a helper class with a method that took any entity with that interface and checked the current localisation and return the correct version of the text.
public interface IBilingualEntity
{
// Defines a consistent interface that indicates which language version
// each thing is in.
string Ar_Name { get; }
string En_Name { get; }
}
public partial MyEntity : IBilingualEntity
{
// This is a class generate by Entity Framework. But it could
// be anything really if you are using some other framework.
//
// Nothing to do here as the other side of the partial
// should already implement the interface with the code
// generated from Entity Framework. If not, implement the
// interface and return the correct language version in
// the property.
}
// This is the helper that works out which language version to use.
public class BilingualHelper
{
public string GetName(IBilingualEntity entity)
{
// NOTE: You may have to strip away the region part of the name
// but off the top of my head I can't remember the format.
// If you are using something else to store the culture you'll
// have to reference that instead.
var cultureName = Thread.CurrentThread.CurrentUICulture.Name;
if (cultureName == "ar")
return entity.Ar_Name;
return entity.En_Name;
}
}
I have a web solution (in VS2010) with two sub-projects:
Domain which holds the Model classes (mapped to database tables via Entity Framework) and Services which (besides other stuff) are responsible for CRUD operations
WebUI which references the Domain project
For the first pages I've created I have used the Model classes from the Domain project directly as Model in my strongly typed Views because the classes were small and I wanted to display and modify all properties.
Now I have a page which should only work with a small part of all properties of the corresponding Domain Model. I retrieve those properties by using a projection of the query result in my Service class. But I need to project into a type - and here come my questions about the solutions I can think of:
I introduce ViewModels which live in the WebUI project and expose IQueryables and the EF data context from the service to the WebUI project. Then I could directly project into those ViewModels.
If I don't want to expose IQueryables and the EF data context I put the ViewModel classes in the Domain project, then I can return the ViewModels directly as result of the queries and projections from the Service classes.
In addition to the ViewModels in the WebUI project I introduce Data transfer objects which move the data from the queries in the Service classes to the ViewModels.
Solution 1 and 2 look like the same amount of work and I am inclined to prefer solution 2 to keep all the database concerns in a separate project. But somehow it sounds wrong to have View-Models in the Domain project.
Solution 3 sounds like a lot more work since I have more classes to create and to care about the Model-DTO-ViewModel mapping. I also don't understand what would be the difference between the DTOs and the ViewModels. Aren't the ViewModels exactly the collection of the selected properties of my Model class which I want to display? Wouldn't they contain the same members as the DTOs? Why would I want to differentiate between ViewModels and DTO?
Which of these three solutions is preferable and what are the benefits and downsides? Are there other options?
Thank you for feedback in advance!
Edit (because I had perhaps a too long wall of text and have been asked for code)
Example: I have a Customer Entity ...
public class Customer
{
public int ID { get; set; }
public string Name { get; set; }
public City { get; set; }
// ... and many more properties
}
... and want to create a View which only shows (and perhaps allows to edit) the Name of customers in a list. In a Service class I extract the data I need for the View via a projection:
public class CustomerService
{
public List<SomeClass1> GetCustomerNameList()
{
using (var dbContext = new MyDbContext())
{
return dbContext.Customers
.Select(c => new SomeClass1
{
ID = c.ID,
Name = c.Name
})
.ToList();
}
}
}
Then there is a CustomerController with an action method. How should this look like?
Either this way (a) ...
public ActionResult Index()
{
List<SomeClass1> list = _service.GetCustomerNameList();
return View(list);
}
... or better this way (b):
public ActionResult Index()
{
List<SomeClass1> list = _service.GetCustomerNameList();
List<SomeClass2> newList = CreateNewList(list);
return View(newList);
}
With respect to option 3 above I'd say: SomeClass1 (lives in Domain project) is a DTO and SomeClass2 (lives in WebUI project) is a ViewModel.
I am wondering if it ever makes sense to distinguish the two classes. Why wouldn't I always choose option (a) for the controller action (because it's easier)? Are there reasons to introduce the ViewModel (SomeClass2) in addition to the DTO (SomeClass1)?
I would solve your problem by using an auto-mapping tool (like AutoMapper) to do the mapping for you. In cases where the mapping is easy (for example if all properties from one class should be mapped to properties with the same name on another class) AutoMapper will be able to do all the hook-up work for you, and you'll have to give a couple of lines of code to note that there should be a map between the two at all.
That way, you can have your entities in Domain, and a couple of view model classes in your WebUI, and somewhere (preferrably in WebUI or a sub namespace of the same) define maps between them. Your view models will in effect be DTOs, but you won't have to worry much about the conversion process between the domain and your DTO classes.
Note: I would strongly recommend against giving your Domain entities straight to the views of your MVC web UI. You don't want EF to "stick around" all the way to the front-end layer, in case you later want to use something other than EF.
introduce ViewModels which live in the
WebUI project and expose IQueryables
and the EF data context from the
service to the WebUI project. Then I
could directly project into those
ViewModels.
The trouble with this is you soon run into problems using EF trying to 'flatten' models. I encountered something similar when I had a CommentViewModel class that looked like this:
public class CommentViewModel
{
public string Content { get; set; }
public string DateCreated { get; set; }
}
The following EF4 query projection to the CommentViewModel wouldn't work as the couldn't translate the ToString() method into SQL:
var comments = from c in DbSet where c.PostId == postId
select new CommentViewModel()
{
Content = c.Content,
DateCreated = c.DateCreated.ToShortTimeString()
};
Using something like Automapper is a good choice, especially if you have a lot of conversions to make. However, you can also create your own converters that basically convert your domain model to your view model. In my case I created my own extension methods to convert my Comment domain model to my CommentViewModel like this:
public static class ViewModelConverters
{
public static CommentViewModel ToCommentViewModel(this Comment comment)
{
return new CommentViewModel()
{
Content = comment.Content,
DateCreated = comment.DateCreated.ToShortDateString()
};
}
public static IEnumerable<CommentViewModel> ToCommentViewModelList(this IEnumerable<Comment> comments)
{
List<CommentViewModel> commentModels = new List<CommentViewModel>(comments.Count());
foreach (var c in comments)
{
commentModels.Add(c.ToCommentViewModel());
}
return commentModels;
}
}
Basically what I do is perform a standard EF query to bring back a domain model and then use the extension methods to convert the results to a view model. For example, the following methods illustrate the usage:
public Comment GetComment(int commentId)
{
return CommentRepository.GetById(commentId);
}
public CommentViewModel GetCommentViewModel(int commentId)
{
return CommentRepository.GetById(commentId).ToCommentViewModel();
}
public IEnumerable<Comment> GetCommentsForPost(int postId)
{
return CommentRepository.GetCommentsForPost(postId);
}
public IEnumerable<CommentViewModel> GetCommentViewModelsForPost(int postId)
{
return CommentRepository.GetCommentsForPost(postId).ToCommentViewModelList();
}
Talking about Models, ViewModels and DTOs is confusing, personally I don't like to use these terms. I prefer to talk about Domain Entities, Domain Services, Operation Input/Result (aka DTOs). All of these types live in the Domain layer. Operations is the behavior of Entities and Services. Unless you are building a pure CRUD application the presentation layer only deals with Input/Result types, not Entities. You don't need additional ViewModel types, these are the ViewModels (in other words, the Model of the View). The View is there to translate the Operation Results to HTML, but the same Result could be serialized as XML or JSON. What you use as ViewModel is part of the domain, not the presentation layer.
I'm trying to create a collection class in Flex that is limited to housing a specific type of data that i am using (an interface). I have chosen not to extend the ArrayCollection class as it's too generic and doesn't really give me the compile time safety that i'm after. In it's simplistic form my collection contains an array and i manage how objects are added and removed, etc.
What i really want to be able to do is use these collections in for each loops. It definitely doesn't seem as straight forward as say c# where you just implement IEnumerable and IEnumerator (or just using the generic Collection). Is there a way to do this in action script and if so any info on how it is achieved?
Cheers
You need to extend the Flash Proxy class. Extending Proxy allows you to alter how 'get' and 'set' work, as well as 'for..in' and 'for..each' loops. You can find more details on the Livedocs.
Here's an example for your issue:
package
{
import flash.utils.Proxy;
import flash.utils.flash_proxy;
public class EnumerableColl extends Proxy
{
private var _coll:Array;
public function EnumerableColl()
{
super();
_coll = [ 'test1', 'test2', 'test3' ];
}
override flash_proxy function nextNameIndex( index:int ):int
{
if ( index >= _coll.length ) return 0;
return index + 1;
}
override flash_proxy function nextValue( index:int ):*
{
return _coll[ index - 1];
}
}
}
Take a look at Vector<>. That is about as best as you can go for a typed collection in Flex (4 onwards). However, you will need to implement your own class otherwise. One way, it seems, is to use the Iterator Pattern.
Also, take a look at this SO post.