I am using ExtJS 4, and have a model with an association hasMany defined.
ModelA -> hasMany -> ModelB
I use GridA to show the data from ModelA. On clicking a record in GridA, I use a rowSelect event to create GridB which use ModelA.ModelB() as a store.
It all goes well until I change a record in ModelB. The record does get updated in the hierarchy, but when I execute StoreA.save(), no change is sent back to the server. It does not notice the changes in associations. How do I save this data, without hacking the architecture?
I am expecting the Model to be able to save, exactly the way it loads.
Also when I change a record in ModelA, it gets sent back as only ModelA and not as ModelA->ModelB, even when that record has ModelB data.
Thanks
Yeah I don't think this whole model hierarchy is fully functional yet to the level that you expected. You can assume that only the things that this Doc mentioned work: http://docs.sencha.com/ext-js/4-0/#!/api/Ext.data.Model
Model relations are not well implemented yet, and ExtJS 4.1 is not making any improvements on the implementation either, other than a few important bug fixes. To learn more check my blog at http://blog.neolocus.com/2011/12/extjs-4-and-model-associations/
Related
I have this unique requirement where each time a particular Content Fragment is updated in AEM, all the Experience Fragments referencing that particular Content Fragment need to be automatically exported to Adobe Target.
Thinking about using SQL2 query to retrieve XFs referencing a particular CF and then incorporating this into a workflow process. Also, wondering if I can leverage aem OOTB workflow process called "Export to Target" in this.
Not really sure of how to call this "Export to Target" process on each Experience Fragment that we need to export to Target or is this possible at all?
Wondering if anyone has ever come across this requirement and succeeded.
Highly appreciate any tips or suggestions in this regard. Many Thanks in advance.
Whenever a Content Fragment is created or updated an OSGi event is triggered. All events are logged under http://localhost:4502/system/console/events. You could write a EventListener or EventHandler, get the path of the event, get the Resource and adapt it to com.adobe.cq.dam.cfm.ContentFragment. The topic for these events is "com/day/cq/dam" or in this constant.
From the adapted Class or Resource you can get informations about the model and if it's the model you want to process.
To find all references I would also create an oak index and use SQL2 query to find all references.
The query would be something like this:
select [jcr:path], [jcr:score], * from [nt:base] as a where contains(*, '"/content/dam/myReferencedModel"')
If you have all referencing XF's you can kick off any workflow via WorkflowService:
#Reference
private WorkflowService workflowService;
WorkflowSession wfSession = workflowService.getWorkflowSession(session);
WorkflowModel wfModel = wfSession.getModel("/var/workflow/models/mymodel");
WorkflowData wfData = wfSession.newWorkflowData("JCR_PATH", "/payload");
wfSession.startWorkflow(wfModel, wfData);
I have a use case where I used different models for the GET and POST actions in my controller. This works great for my view, because most of the data goes into labels. The model for the GET method contains 10 properties, but the model for the POST method only needs 3.
This GET view renders a form, which only needs 3 of these properties, not all 10. Thus, the model for the POST method accepts a model class which contains only these 3 properties. Therefore, the ASP.Net MVC model binder populates the model class parameter on my POST method with only these 3 necessary properties, and all is well.
Here's the question: When I encounter some business rule violation in the POST method, and want to use ModelState.AddModelError, and re-display the original view, I no longer have the 7 properties that were not POSTed, as they were not part of the form, and are not part of the model class which this method takes as its parameter.
Currently, I'm calling into a builder to return an instance of the model class for the POST method, and have the GET method itself delegating to the same builder. So, in these cases, when there is some business rule violation in the POST method, I return a View("OriginalGetView", originalGetModel). How can I use ModelState.AddModelError in this case, in the POST method, if I want to send custom messages back to the view, using a completely different model class?
It seemed way too lazy to use the same model class for both the GET and POST methods, given that their needs were so different. What is the best practice here? I see a lot of people recommending to use the same model for both methods, and to POST all of the fields back from hidden form fields, but that just seems like a waste of bandwidth in the majority of cases, and it feels ugly to be sending things like "VendorName" back to the server, when I already have "VendorId".
I may be misunderstanding what you are trying to do, but make sure you aren't being penny-wise and pound foolish. I see you may only want to post the identifiers and not necessarily the descriptors. But it sounds like you have to re-display the view after posting...if so you can just access the model properties if you post the same model that is in the get. If you only post the identifiers, you have to spend time re-accessing the database to get the description values(i.e. vendorname as you describe) using the vendor id no? Wouldn't that also be extra processing? Like I said, I could be misunderstanding your post, but for consistency using the same view model for your view to get and post makes the most sense to me.
Hidden Inputs maybe the best solution here still I think, even on 2g you shouldn't create any lag unless unless the values of your Model properties are long strings or something encrypted or xml.
So your .cshtml would have this in it for the 4 properties not currently included in the form:
<form>
#Html.HiddenFor(m => m.Property1)
#Html.HiddenFor(m => m.Property2)
#Html.HiddenFor(m => m.Property3)
#Html.HiddenFor(m => m.Property4)
But you could also get the model state errors from the original posted model and recreate the ModelError state in your response model to get around using hidden inputs.
I just found this guide (not the answer with Green Checkmark but the highest upped Answer: ASP.NET MVC - How to Preserve ModelState Errors Across RedirectToAction?
Note: if you need to copy model properties from Model to another Model (of the same type or different type), in a cleaner way, check out AutoMapper.
Perhaps this could help with what you were trying to achieve - 'Model' level errors - which wouldn't need to attach to a specific field/property - but can be displayed in a Global area.
https://stackoverflow.com/a/53716648/10257093
I will try to be as concise as possible. I'm using Flex/Hibernate technologies for my app. I also use Cairngorm micro-architecture for Flex. Because i'm beginner, i have probably misunderstand something about Caringorm's ModelLocator purpose. I have following problem...
Suppose that we have next data model:
USER ----------------> TOPIC -------------> COMMENT
1 M 1 M
User can start many topics, topics can have many comments etc. It is pretty simple model, just for example. In hibernate, i use EAGER fetching strategy for unidirectional USER->TOPIC and TOPIC->COMMENT relations(here is no question about best practices etc, this is just example of problem).
My ModelLocator looks like this:
...
public class ModelLocator ....
{
//private instance, private constructor, getInstance() etc...
...
//app state
public var users:ArrayCollection;
public var selectedUser:UserVO;
public var selectedTopic:TopicVO;
}
Because i use eager fetching, i can 'walk' through all object graph on my Flex client without hitting the database. This is ok as long as i don't need to insert, update, or delete some of the domain instances. But when that comes, problems with synchronization arise.
For example, if i want to show details about some user from some UserListView, when user(actor) select that user in list, i will take selected index in UserList, get element from users ArrayCollection in ModelLocator at selected index and show details about selected user.
When i want to insert new User, ok, I will save that user in database and in IResponder result method i will add that user in ModelLocator.users ArrayCollection.
But, when i want to add new topic for some user, if i still want to use convenience of EAGER fetching, i need to reload user list again... And to add topic to selected user... And if user is in some other location(indirectly), i need to insert topic there also.
Update is even worst. In that case i need to write even some logic...
My question: is this good way of using ModelLocator in Cairngorm? It seems to me that, because of mentioned, EAGER fetching is somehow pointless. In case of using EAGER fetching, synchronization on Flex client can become big problem. Should I always hit database in order to manipulate with my domain model?
EDIT:
It seems that i didn't make myself clear enough. Excuse me for that.
Ok, i use Spring in technology stack also and DTO(DVO) pattern with flex/spring (de)serializer, but i just wanted to stay out of that because i'm trying to point out how do you stay synchronized with database state in your flex app. I don't even mention multi-user scenario and poling/pushing topic which is, maybe, my solution because i use standard request-response mechanism. I didn't provide some concrete code, because this seems conceptual problem for me, and i use standard Cairngorm terms in order to explain pseudo-names which i use for class names, var names etc.
I'll try to 'simplify' again: you have flex client for administration of above mentioned domain(CRUD for each of domain classes), you have ListOfUsersView(shows list of users with basic infos about them), UserDetailsView(shows user details and list of user topics with delete option for each of topic), InsertNewUserTopicView(form to insert new topic) etc.
Each of view which displays some infos is synchronized with ModelLocator state variables, for example:
ListOfUsersView ------binded to------> users:ArrayCollection in ModelLocator
UserDetailsView ------binded to------> selectedUser:UserVO in ModelLocator
etc.
View state transition look like this:
ListOfUsersView----detailsClick---->UserDetailsView---insertTopic--->InsertTopicView
So when i click on "Details" button in ListOfUsersView, in my logic, i get index of selected row in ListOfUsers, after that i take UserVO object from users:ArrayCollection in ModelLocator at mentioned index, after that i set that UserVO object as selectedUser:UserVO in ModelLocator and after that i change view state to UserDetailsView(it shows user details and selectedUser.topics) which is synchronized with selectedUser:UserVO in ModelLocator.
Now, i click "Insert new topic" button on UserDetailsView which results in InsertTopicView form. I enter some data, click "Save topic"(after successful save, UserDetailsView is shown again) and problem arise.
Because of my EAGER-ly fetched objects, i didn't hit the database in mentioned transitions and because of that there are two places for which i need to be concerned when insert new topic for selected user: one is instance of selectedUser object in users:ArrayCollection (because my logic select users from that collection and shows them in UserDetailsView), and second is selectedUser:UserVO(in order to sync UserDetailsView which comes after successfull save operation).
So, again my question arises... Should i hit database in every transition, should i reload users:ArrayCollection and selectedUser:UserVO after save in order to synchronize database state with flex client, should i take saved topic and on client side, without hitting the database, programmatically pass all places which i need to update or...?
It seems to me that EAGER-ly fetched object with their associations is not good idea. Am i wrong?
Or, to 'simplify' :) again, what should you do in the mentioned scenario? So, you need to handle click on "Save topic" button, and now what...?
Again, i really try to explain this as plastic as possible because i'm confused with this. So, please forgive me for my long post.
From my point of view the point isn't in fetching mode itself but in client/server interaction. From my previous experience with it I've finally found some disadvantages of using pure domain objects (especially with eager fetching) for client/server interaction:
You have to pass all the child collections maybe without necessity to use them on a client side. In your case it is very likely you'll display topics and comments not for all users you get from server. The most like situation you need to display user list then display topics for one of the selected users and then comments for one of the selected topics. But in current implementation you receive all the topics and comments even if they are not needed to display. It is very possible you'll receive all your DB in a single query.
Another problem is it can be very insecure to get all the user data (or some other data) with all fields (emails, addresses, passwords, credit card numbers etc).
I think there can be other reasons not to use pure domain objects especially with eager fetching.
I suggest you to introduce some Mapper (or Assembler) layer to convert your domain objects to Data Transfer Objects aka DTO. So every query to your service layer will receive data from your DAO or Active Record and then convert it to corresponding DTO using corresponding Mapper. So you can get user list without private data and query some additional user details with a separate query.
On a client side you can use these DTOs directly or convert them into client domain objects. You can do it in your Cairngorm responders.
This way you can avoid a lot of your client side problems which you described.
For a Mapper layer you can use Dozer library or create your own lightweight mappers.
Hope this helps!
EDIT
What about your details I'd prefer to get user list with necessary displayable fields like first name and last name (to display in list). Say a list of SimpleUserRepresentationDTO.
Then if user requests user details for editing you request UserDetailsDTO for that user and fill tour selectedUser fields in model with it. The same is for topics.
The only problem is displaying list of users after user details editing. You can:
Request the whole list again. The advantage is you can display changes performed by other users. But if the list is too long it can be very ineffective to query all the users each time even if they are SimpleUserRepresentationDTO with minimal data.
When you get success from server on user details saving you can find corresponding user in model's user list and replace changed details there.
Tell you the truth, there's no good way of using Cairngorm. It's a crap framework.
I'm not too sure exactly what you mean by eager fetching (or what exactly is your problem), but whatever it is, it's still a request/response kind of deal and this shouldn't be a problem per say unless you're not doing something right; in which case I can't see your code.
As for frameworks, I recommend you look at RobotLegs or Parsley.
Look at the "dpHibernate" project. It implements "lazy loading" on the Flex client.
There seem to be multiple means of passing model data from controllers in asp.net mvc to views. Its not clear to me if there's a recommended approach in the mvc v1 and v2 releases or if like most things in life, it depends. I've seen several approaches:
Option 1 - Populate the controller's ViewData dixtionary in either an icky string-based indexing way with casting in the view, or the in a strongly typed way by creating a strongly typed custom model class and passing that via ViewData.
Option 2 - Use ViewData.Model, which I'm not sure I even understand.
Option 3 - Use ViewPage.Model, in which case I'm not sure how you pass the model data from the controller.
I've seen a number of posts poo-pooing options 1 and 2 but I don't understand why. These posts seem to highly recommend 3 in most cases.
How do you approach this? Is there a standard way?
Every view 'should' have a specific model. This is sometimes more work so people use short cuts like ViewData, which works but is just not as clean and type safe in my opinion, so I prefer to have everything in the view's model.
You can then make all your views stongly typed. This is a very clean way to do so. Then in your controller you just call the view like:
YourViewModel model = new YourViewModel()
{
// initialize the data here
};
View(model);
Then in your views you can access all the data via ViewPage Model and it is all type safe and enforced from the controller as well.
EDIT from comments:
You don't need to use ViewData at all if you don't want. You can encapsulate all the data your view needs in a model. Just like the example you quoted with ProductsListViewData. It's just a model that contains all the items that were going to be stored in the ViewData. Both ways work but when you encapsulate it in a class (preferred method where everything is in the model) then all the bits and pieces are strongly typed.
ViewData is a generic container so even though you can just put anything you want into it, it is not type safe and therefore not as 'clean'. It comes down to preference and maintainability. There is only option 1 and 3. Your option 2 is misunderstood and is just option 3 in reality. There is no ViewData.Model just ViewPage.Model.
One approach you may wish to consider as your views become more complex, is to reserve the use of Models for input fields, and use ViewData to support anything else the View needs to render.
There are at least a couple of arguments to support this:
You have a master-page that requires some data to be present (e.g. something like the StackOverflow user information in the header). Applying a site-wide ActionFilter makes it easy to populate this information in ViewData after every action. To put it in model would require that every other Model in the site then inherit from a base Model (this may not seem bad initially, but it can become complicated quickly).
When you are validating a posted form, if there are validation errors you are probably going to want to rebind the model (with the invalid fields) back to the view and display validation messages. This is fine, as data in input fields is posted back and will be bound to the model, but what about any other data your view requires to be re-populated? (e.g. drop-down list values, information messages, etc) These will not be posted back, and it can become messy re-populating these onto the model "around" the posted-back input values. It is often simpler to have a method which populates the ViewData with the..view data.
In my experience I have found this approach works well.
And, in MVC3, the dynamic ViewModels means no more string-indexing!
This might be of some help:
When is it right to use ViewData instead of ViewModels?
(I know the following answer is highly arguable, but it's just the way I like to do it)
I would say use ViewData for simple data-tasks, and use the Model for the main purpose of the View. Check out Rob Conerys ViewData helper-classes here to give them a bit more Strongly typed feel:
http://blog.wekeroad.com/2010/01/20/my-favorite-helpers-for-aspnet-mvc
Using Models for absolubtely everything will bloat your project with hundreds of models just to achieve the smallest thing. I mean if you have a User-setting page, you would normally pass a User-model into the view, but if you decide to show some related data like Customers related to this User. You're stuck with the following solutions
You might have to add a List property to the User-model in order to expose the customers to the view. This leads to the Customer-property always being applied to the User-model everywhere else in the project - or make a new simpler User-model.
Make a new action that returns a partial of customers, which you can use with Html.RenderAction.
OR
you could do ViewData["Customers"] = myRepo.GetCustomersRelatedTo(user); // or something like that.
and (if using Robs helpers) in your view:
<%= Html.RenderPartial("CustomerList", Html.ViewData("Customers")) %>
add a PartialView called CustomerList that takes IEnumerable
In my humble opinion this is a cleaner solution and sure - you end up with a magic string here and there, but I'll stick to this approach until someone shows me a project with not a single magic string.
Use the tools we have in the Framework to get the job done. and Keep it simple s... ;)
I am pretty new to this stuff but I am running into a concept-wall and I keep going back and forth with the best way to handle the problem.
I have a multi-view process to filling out a "New User Form". Each view has a small part of the entire form. In each view I have a model and the model has properties set to an instance of a LINQ to SQL class (for pre-populating) along with dropdown data (state, country). I also thought I should have a model (value object) that represents the entire form. This value object has properties for each LINQ class as well. So I made the view take the value object as a dependency injection. Then what? Just set a property to ViewData to send in multiple models? Seems like a bad idea since I would have to do that to every view. Should all view models come from a base class with the value object?
I might be way off already. Hopefully someone can help me get back on track. The ultimate goal is to have an object that represents the state/data of a form that spans multiple views and the form fields should populate if data is present.
Thanks for your patience!
Okay, so I am going to try to answer my own question but I am still not sure about things. I am going to use the info I got here: http://www.asp.net/Learn/mvc/tutorial-13-cs.aspx to create an instance of the value object that will be available to every view. Then I am sending the instance (or a property of) into the view model through it's constructor.
I am still working on how to keep the instance of the value object through all pages but I am assuming it will have to be done through a session variable of sorts.