I'm starting with web development and Spring MVC.
I currently have a good knowledge about create a simple CRUD.
But now, I need to do something more advanced.
I need to create a CRUD to an entity with details, like a Invoice with items/products.
What is the best way to manage this CRUD without persist the Invoice with no items?
How can I persist the entity only when the user ends to enter the fully data (invoice + items) ?
How will be the Controller to do this?
I already found this Explain this Spring MVC Controller behavior, but it doesn't clarify my questions.
Thanks!
Beto, have a look at the spring.io/guides page for clear examples of how to do this.
Especially review the 3 big tutorials at bottom of page (best one is http://spring.io/guides/tutorials/web/).
That will give you good answers and explanations behind them.
Related
I was wondering what would be the best way to achieve the question that I have posted? So for instance if I pressed a button it would go to the controller which would go to this address https://www.premierleague.com/results and then in this address it would get the home team name and away team name. Would this be possible via Spring. Which I can then save into the database.
Is there any tutorials, that people know off that could answer this question?
Cheers Jeff
You want to perform a http-query against another REST-Service within your application, which of course can be done.
I suggests you to look into this tutorial by Spring: Spring - Consuming Rest
This one should get you started on how to use the built in http-client of Spring.
Edit: The url you posted of course serves a complete website, its not a REST-Endpoint. If the premiere league offers an API, you should use that. If not you can of course request the whole webpage and scrape it for the information you need.
I am trying to learn backbone.js to make a web application.This is my first time with a javascript framework and I am fairly confused with some of the stuff.
I have been developing in codeigniter for a while so I do have a understanding of the MVC architecture.
My question is how do I get the data from the backbone.js front end to my codeigniter controller and save it in the database. for example to implement a simple login/register functionality with CI and backbone, how should I proceed. If anyone can guide me step step then that would be great or point me to the right resource. Thank you.
PS: I know that I have to implement a REST api with my codeigniter but I don't know how? so if someone can provide a basic controller example it'd be really helpful.
Here's a tutorial to use the API mentioned in the above reply (by the author of the library himself)
http://net.tutsplus.com/tutorials/php/working-with-restful-services-in-codeigniter-2/
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I realise this might be a little vague but I honestly don't know where else to ask. I have some history with PHP and I am trying to teach myself ASP.NET MVC3.
While I can find a LOT of source material on syntax and tutorials on various parts. I've started it off and I've got quite a bit going but I'm finding it a bit difficult to figure out exactly how to design the whole thing with regards to where to put things and I'm not entirely certain who I can ask or where I can find these things out?
The project I'm working on, in an attempt to teach myself is a form of online rpg game site. I've got user registration and log in, I wrote a custom membership provider to fit that to my existing database structure. But the trouble I'm having knowing where to do database lookups and how to store data etc. For example, let's say you log in, you have a certain amount of gold. On the right side of the status bar on the _layout page it will always display this value. Where do you look this up? How do you remember it? In the controller? Which controller? Etc etc.
Can anyone maybe recommend either a good set of advanced tutorials or some kind of forum where this can be discussed?
Thanks!
I learned everything i know from:
Getting Started with ASP.NET MVC 3
ScottGu's Blog -> awesome blog entries on mvc 3
Must see the Music Store Tutorial App
Check out a great book by Steve Sanderson - Ive used the previous two editions to get me upto speed with MVC.
Pro ASP.NET MVC 3
If your looking to use Entity Framework then I can also recommend;
Programming Entity Framework
The MSDN and ASP.NET sites have a LOT to offer on MVC3. I would also suggest buying the two MVC3 books by Phil Haack and Steve Sanderson.
http://www.asp.net/mvc/tutorials/getting-started-with-aspnet-mvc3
http://www.asp.net/mvc/tutorials/overview/creating-a-mvc-3-application-with-razor-and-unobtrusive-javascript
http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application
http://msdn.microsoft.com/en-us/library/gg416514%28v=vs.98%29.aspx
http://weblogs.asp.net/jgalloway/archive/2011/03/17/asp-net-mvc-3-roundup-of-tutorials-videos-labs-and-other-assorted-training-materials.aspx
Those are all good links and tutorials. In addition, you are going to want to have a separate database for your data vs. your Authentication and Authorization. This will allow decoupling and better security. You should be storing data in a database, and then the model will hold access to that database through a DAL (Data Access Layer) usually with the controller holding an instantiated repository of the DAL. In this sense the controller can build objects from the model (and thereby from the database) and then send them to the view through strongly typed objects for you to use in a User Interface.
Nerd Dinner is a pretty good sample of the whole picture, you can download the sample code and play with it.
http://nerddinner.codeplex.com/
The problem I find is a lot of examples don't use best practices for MVC in favour of simplicity and ease of reading in tutorials. So I'll outline some of the things I've found out the hard way and that work for me.
Personally from what I've found is your controller should be responsible for handling information via ViewModels to act as Data Transfer Objects (DTOs) between your business logic and your views, and that's all they should have in them. I choose to never have business logic in the controller and instead opt for a series of service classes designed to deal with their own group of responsibilities (IoC takes care of most concerns the Services may have).
This is done to keep the business logic DRY and to make it easier should you decide to try making a mobile version of your site later, or maybe expose a public WebService/API to your data.
The views should each use ViewModels specifically meant for each view, and these views should ONLY consist of primitive types or other view models. Never use a data entity from your ORM directly, though I'll be honest I have been known to break my own rule on this when it comes to views that only display information, but I usually pay for it later. Validation rules imposed on your data model are not necessarily applicable to a form and data loaded on your entity may not be relevant to your view either. ORM's that support Lazy Loading complex data entities can cause havoc with some VERY useful 3rd party libraries you can use in MVC like MiniProfiler and Glimpse, not to mention other issues when it comes to rendering these objects in forms for posting back later. So try to stick to flat ViewModels if possible.
I typically name my ViewModels according to their use. so my Register page may use a model called AccountsRegisterViewModel. However when I postback I usually use a different model called AccountsRegisterFormModel. This is because many times there is information I need to pass to render in the view but I really don't care about it (nor will it be present in most cases) on the action that accepts my postback. Also, MVC requires you to disambiguate your actions that use the same name via different parameters so using different view models helps there. For example CreateAccount() to show the account creation page and CreateAccount() that accepts your submission from the form. Though you can explicitly change where each form posts, the main focus with MVC is convention over configuration so I try not to change where forms post back to.
For your specific example of showing relevant information (Gold balance) you're likely going to want to create a Child Action with it's own view that would be responsible for doing it's own data access, or if you want to try your hand at ajax, have the balance be something handled in a smiple partial view that makes a call to a public action that returns JSON.
Those are the practices I've found have worked for me so far.
VS2010 Pro + SqlServer Express.
Having been dropped into ASP.NET MVC 3 with no guidance but the web (2 books on order), I can't even get off the ground.
The MVC itself I get. Not a problem.
PHP, Ruby, and even ghastly WebForms firmly tucked into my toolbelt, with a long history of C++ QT client-server development before that.
Tying ASP.NET MVC 3 to a database using EF4 ORM is killing me.
The goals:
Use database modeled by DBA. I can specify all naming conventions, but code first is not an option!
Import to EDMX. This will be regularly updated using VS tools from the DBA's DB, never edited directly.
Generate partial classes from EDMX, for use as model. This will regularly be updated using VS tools, never edited directly.
Use 'buddy' to extend above model class with code as the Controllers/Views need.
Intuitively use the resulting model, pass it to the view, retrieve posts into it for insert/save, etc...
I've seen and read so many blogs, forum posts, walkthroughs, and stack overflow posts regarding this very use case.
I even tried riding the magic unicorn, followed by the latest 4.2beta1 with DbContext generators.
But can't get off the ground.
I follow instructions, but just not understanding how to do anything with it.
What conventions does the 'buddy' require (if any)? How do I use it? How do I get data with it? How do I write data?
Every example looks different. MVC guides are always focused on the UI side. EF guides don't cover usage in the MVC.
These are basic questions, and I'm feeling like the most incompetent idiot in the WWW right now.
Is anyone out there currently using MVC3 & EF4.x in the way I describe above?
This video is a good starting resource. Its a video of a guy creating an app from scratch that uses entity and a sql database (though he makes the db in the video, its still good for seeing some basics in action). You can see how he pulls data from the database, displays it on the page, and saves changes back to the database.
The first question I would ask is why are you stuck on using EF as an ORM or even insisting an ORM at all? I'd choose tools to suit the job here, especially given the constraints of the data layer.
Buddy classes were a concept invented in a day when the main .NET ORMs had no code-first option as ORM-encumbered class instances really don't behave well under things like model binding. Nevermind you could not decorate them with the DataAnnotations one used to indicate fields were required. Typically, the technical requirement is to use [MetadataType] attributes to tie your buddies to your models and perhaps something like AutoMapper to map data to and fro.
All that said, as a guy who has a few apps with lots of buddies and lots of automapping going on, you might want to think otherwise -- it is a bit of a maintenance nightmare. I'm living it.
There are some really good getting-started videos and tutorials right on ASP.NET MVC's site. The "Model (Data)" section is Entity Framework focused and touches on hot/trending topics like Repositories and Units Of Work.
For a relatively simple application, can Webflow be employed to reduce the need to create form controllers? Well, certainly it can, but I guess what I'm asking is: can and should I write an entire application using Webflow for all of the controller / view logic if my goal for doing so is to reduce the amount of code that I write?
I'm struggling my way through the (poor) Webflow documentation and am wondering if it's worth it, or if I should just stick to regular MVC.
The use case for Web Flow is to solve the problem involved with controller logic that spans multiple-page navigation (a pageflow, or wizard). If you don't have to have a form split across multiple pages (or need several small forms to participate in a single transaction), you probably don't need a Pageflow.
Most applications do need this, however. Anything more than simple CRUD stands to benefit.
Pageflows provide a natural cache for the data and can solve problems involved otherwise when using back button navigation and multiple frames/tabs.
If you are thinking about how to store data that needs to live longer than a single request (the common but misguided view is to store in the HttpSession) then you will definitely get something out of Web Flow. If you're not doing anything like that and processing everything at the request-scope then odds are you don't need Web Flow.
Update:
Web Flow can eliminate the need for specialized controller classes to accomplish following a path of page transitions/form updates along a predefined workflow. If you don't need to do this, you can save yourself a lot of configuration/complexity just by using MVC.
SpringMVC and Spring WebFlow can be used together where appropriate - there is nothing odd about that.
If you have a use-case which is simple crud and you think you could easily implement this using SpringMVC then that's probably the right choice.
Note: You could also achieve this in WebFlow too and that neither better or worst.
If you have complicated wizard logic and state management requirements then WebFlow is great plus you get many other features for free like transactions and persistence support (Version-2).