I am new to android and the tutorials i watched to solve the loader is that they say use CursorLoader while using content provider but when i went to developer site they say CursorLoader is deprecated and Loader classes are also deprecated. They suggest to use LiveData and ViewModel instead but i have no idea to implement this.
consider i want to retrive data from a content provider using LiveData and ViewModel. Is it possible to do so and if please help. Thank you
Related
I'm using AutoMappper 5.2 in my MVC project. I have made use of IMapper creating profiles which I understand profiles are a way to organise mappings. I am injecting IMapper into my controllers using Simple Injector to register an instance.
What I would like to know is can you use them in a way where you only retrieve/set up the profile you need for a specific controller? If so, how would you go about that? If you have to add all the profiles into one mapping configuration object does that have a performance impact or is it marginal?
I cannot find any resources or questions that deals with using a specific type of profile, they only deal with creating and registering them.
I think my answer to a similar question might help you. It is the last answer here: How to register AutoMapper 4.2.0 with Simple Injector.
It's basically what Steven said.. you need to create a generic profile wrapper that implements the IMapper interface, with the generic argument being a specific profile. This allows you to create any number of profiles, batch-register them all, and to inject only the one that you need in your controller:
ProfileMapper<ApplicationProfile> appProfileMapper;
ProfileMapper<MvcProfile> mvcProfileMapper;
ProfileMapper<GuestProfile> guestProfile;
I would like to use Autofac IOC container in my bot application (based on BotFramework).
I can see that framework itself already uses it.
But I can't figure out how to do it gracefully... I don't want to resolve my components on every post invocation (it will slow down my post method execution).
I appreciate if you share code snippets with your solutions.
Thanks in advance!
You can use the Autofac container being used in the framework in the Global.asax and perform your own registrations.
The key code pieces are:
var builder = new ContainerBuilder();
// perform your registrations on the builder
// update the container being used by the framework
builder.Update(Conversation.Container);
For a real implementation of this, you could take a look to the ContosoFlowers sample where you will see that a Module is used to register the application specific components. Here is the Global.asax and here the actual module.
I have been using for a while but still I am confuse on what to include in my controllers specifically "When should I use Model and When to Use Service"?
I am confused if I am making the right thing.
I would suggest to never use models directly into the controllers.. Adopt the repository-pattern which enables the use of dependency injection of services into the controller.. Use Service Layer to contain the business logic.. In this way all the related codes would be onto similar layer.
Reference for repository pattern:
http://heera.it/laravel-repository-pattern#.VuJcVfl97cs
Please don't use model directly in your controller, unless if you are building a very simple application but for a large application, it would be good to use a repository. Kindly take a look at this tutorial https://bosnadev.com/2015/03/07/using-repository-pattern-in-laravel-5/
I am trying to understand the Repository class in Zend Framework in order to choose the right way to create my new software application.
What I need is clarify the concept of the Repository. I have read that I can call the ServiceLocator, get the EntityManager, now call the Repository from my Controller action and execute the Doctrine methods passing the data to the view:
Then I have read this answer in stackoverflow and now I am a little bit confused: https://stackoverflow.com/a/14103376/1034359
So what is the right way or better way to call the Entities ?
Regards
Use an existing module to connect to the doctrine orm library: http://modules.zendframework.com/?query=Doctrine+orm
I will start to code a new Web application soon. The application will be built using ASP.Net MVC 3 and Entity Framework 4.1 (Database First approach). Instead of using the default EntityObject classes, I will create POCO classes using the ADO.NET POCO Entity Generator.
When I create POCOs using this tool, it automatically adds the Virtual keyword to all properties for change tracking and navigation properties for lazy loading.
I have however read and seen from demonstrations, that Julie Lerman (EF Guru!) seems to turn off lazy loading and also modifies her POCO template so that the Virtual keyword is removed from her POCO classes. Julie states the reason why she does this is because she is writing applications for WCF services and using the Virtual keyword with this causes a Serialization issue. She says, as an object is getting serialized, the serializer is touching the navigation properties which then triggers lazy loading, and before you know it you are pulling the whole database across the wire.
I think Julie was perhaps exagarating when she said this could pull the whole database across the wire, however, even so, this thought scares me!
My question is (finally), should I also remove the Virtual keyword from my POCO classes for my MVC application and use DectectChanges for my change tracking and Eager Loading to request navigation properties.
Your help with this would be greatly appreciated.
Thanks as ever.
Serialization can indeed trigger lazy loading because the getter of the navigation property doesn't have a way to detect if the caller is the serializer or user code.
This is not the only issue: whether you have virtual navigation properties or all properties as virtual EF will create a proxy type at runtime for your entities, therefore entity instances the serializer will have to deal with at runtime will typically be of a type different from the one you defined.
Julie's recommendations are the simplest and most reasonable way to deal with the issues, but if you still want to work with the capabilities of proxies most of the time and only sometimes serialize them with WCF, there are other workarounds available:
You can use a DataContractResolver to map the proxy types to be serialized as the original types
You can also turn off lazy loading only when you are about to serialize a graph
More details are contained in this blog post: http://blogs.msdn.com/b/adonet/archive/2010/01/05/poco-proxies-part-2-serializing-poco-proxies.aspx
Besides this, my recommendation would be that you use the DbContext template and not the POCO template. DbContext is the new API we released as part of EF 4.1 with the goal of providing greater productivity. It has several advantages like the fact that it will automatically perform DetectChanges so that you won't need in general to care about calling the method yourself. Also the POCO entities we generate for DbContext are simpler than the ones that we generate with the POCO templates. You should be able to find lots of MVC exampels using DbContext.
Well it depends on your need, if you are going to serialize your POCO classes than yes you should remove them (For example: when using WCF services or basically anything that will serialize your entire object). But if you are just building a web app that needs to access your classes than I would leave them in your classes as you control the objects that you will access in your classes through your code.