I am working on an ASP.NET MVC project and I am trying to get it integrated with facebook by using facebook connect API. Now, I am having a small problem in imagining how the conceptual layout would be. I am using the repository model in MVC, I have my own DB. I want to be able to fetch user’s information from FB, and maybe store their fb_uid in my database (is that legal anyway?) I also want to be able to post stories into user’s mini feed. I have a model class called User; this class has to be filled with data from both my internal DB, and FB database. I have repository classes to communicate with the database, and I don’t really know where/which part should communicate with FB? I thought of using the FBDeveloperToolkit, but from what I have read in this forum, the toolkit is a bit out of date! I don’t know if I should use XFBML and pure javascript functions? And if yes, how can pull the data back to my DB, for example user’s fb_uid? And does that mean I will be directly calling the API functions from my presentation layer?
Can anyone please help me in this?
Thanks!
I would suggest a FacebookService layer that implements a subset of functionality you need from the Facebook API. In the DDD world it's called an Anti-Corruption Layer.
Related
I am relatively new to the UI5 Framework and I have a new use-case in my company that I want to implement with UI5 and OData Services.
Basically the application has two functionalities with different stakeholder:
Role A is able to create new requirements
Role B is able to check the requirements and update them with new
information
How can I implement this the best way? My previous thoughts on that:
Possibility 1:
I have the OData Service in the Backend that is used by two separated application depending on the role. The access is controlled through the launchpad over the PCFG objects. So a specific user can only use the application that he actually needs. I believe that matches the basic granularity of Fiori apps. On the other hand, it invalidates the DRY principle since I would have redundant code like most of the view.
Possibility 2:
I check in the UI5 Framework or OData Service which user is currently using the app and enable/disable the required controls in the controller class. I haven’t come across on how to do this. Is there a way to check which user is logged on? Or how can I implement in the OData service, that only specific information is delivered to the client?
What is the correct way to implement such a use case? Is there a better option that I am not aware of? I would appreciate any thoughts on that matter, thanks :)
Best regards
Suggested Approach
If two roles do not share any common functionalities, then I would go for two separate UI5 apps, so as to keep them simple. In that case, each app would have it's own OData service. But in the backend, you can always have a common class for 'Requirements' which is called by both the OData service implementations. (So as to maximize code reuse). So most of your business logic should be inside the 'Requirement' class, and the OData implementations serve as dispatchers.
To check which user is logged in
This is a common requirement for most of the business applications and it is possible in Gateway/ABAP as well. Within the ABAP context, there is always a system variable available named SY-UNAME, which will provide you the current logged in user's name. You can use it further to derive the user's role.
I'm still not used to the MVCS design pattern. I read in a book that if I was planning to create an app that gets information from an external source, it's better to use MVCS instead of MVC.
I'm currently working on an ios app that gets information from multiple external sources. For example, I'll be fetching info about the weather from a web service, driving directions/time probably from Google, and data from our database via a web service as well.
My question is, do I need to create more than one store object in this situation? Like create a store object for each of the external sources? Or do I just create one for all of them?
I think it really depends on your design approach as you can have dozens of different design approaches which all respect the MVC principles and that therefore are all correct.
Personally I would suggest to try to decompose the problem as much as you can in smaller problems, in order to get the most from the flexibility that a objected oriented environment gives you.
In this case, for instance, you could think about having an abstract store class in which you implement the common functionalities you need to have and then subclassing it for each different web service you need to use and implementing the other functionalities related to that specific service. It's just an idea! I hope this helps.
i've a question regarding handling of user logon while porting an application to MVC:
in the "old" WebForm days, developers simply used the SessionState object to set a user to logged-on, by -for example- simply putting the userobject into the SessionState (and this userobject holds simple properties like name/lastlogon/etc.)
this stuff worked very well for us, and i've seen lots of applications doing it that way
yes, i know there is this MembershipProvide-thingy, but i've never used it
Now, in MVC, everybody tells me that "using SessionStat for this is bad" and "apps built that way are flawed in design" and that "there are tons of security risks" and so on.
I've used this method because it worked for the app very reliable, it was simple to implement and it covered all stuff we need.
(Sure, there is the thing with recycling web worker process and emptying the session - but thats not a problem in our case, since the app runs for each country on a dedicated machine)
I've read tutorials, telling me to put that stuff in the DB and -attention- doing a request to the DB to check if the user is logged in, per EACH request? But: Under no circumstances, this is a doable way since i want to keep DB requests on a minimum.
So my question is:
A) whats wrong using this way also in the new MVC app?
B) whats the best way to handle this scenario in a newly built MVC app?
Regarding the session-in-DB-idea: instead of doing this, i'd rater setup an additional service, like a "session-manager" thats get query over the network, but such simple requests should not go to the DB - isn't that a good idea?
Any idea, hint /etc. is highly appreciated since this scenario is really confusing me :-X
A)
A fundamental principal of the asp.net mvc framework is that its stateless. Data is passed around using http requests and sent to the views in viewmodels. Web forms tried to maintain state with viewstate etc thats why you would have seen the logged in user in session approach. Thats not to say session shouldnt be used completely in asp.net mvc, there are some circumstances when it can be useful. Like maintaining a 3 step form process that has to be persisted on the last step. But generally we already have a recommended way to handle the user logins, and thats forms authentication
B)
For accessing the user object, you can create a custom identity implementing the IPrincipal interface and add the required user fields you need. Then set the custom identity in a global filter and access it in your action results. Regarding not wanting to query the database for every request, why dont you just call it for the initial request, then cache the result until the user is updated where you then can reload the object and set it in the custom identity again.
I have a site which has an area that requires authentication. Right now I use the roles attribute on all the controllers in that area, and I run a query to retrieve that users ID, and all their settings.
It seems like a code or design smell to me that I am retrieving the userid and settings each time a controller in that area loads up? I'm not sure if I should be using sessions, or if ASP.Net MVC 2.0 provides some unique way to handle this. Another concern is security.
Overall, I don't really know which way to turn. Design wise I would like the userId and settings retrieved only once when the user logs into the area. Right now I grab the userId each time a controller loads up, and then if required, I query the database for their settings each time as well.
One of the rules about security is that you shouldn't try to do it yourself. There are many pitfalls in doing an authentication system correctly without leaving loopholes or backdoors. Thus, in that regard, you might consider the SqlMembershipProvider that comes with .NET. It can be used with MVC and provides the means to get roles and the current security context, is easy to setup and configure and will be more secure than rolling your own.
If you are not using SQL Server, you have a couple of choices. One solution would be to use something like SQL Server Express or SQL Server Compact Edition to maintain the credentials. Another solution would be to mimic the SqlMembrershipProvider database schema and then write a custom provider that communicates with that schema.
The last choice would be to write a custom MembershipProvider class. While this is still rolling your own, it forces you into the structure of the MembershipProvider so that you can swap it out at a later date for a different one (e.g. ActiveDirectoryMembershipProvider) and provides a common interface for interacting with credentials and logins which for example enables easy use of the built-in Login control.
If you are already using a MembershipProvider and are asking about storing additional user-specific data, then I would suggest the SqlProfileProvider with all the caveats I mentioned above about the SqlMembershipProvider. the ProfileProvider provides a structure for maintain user-specific data with the currently logged on user.
For more information:
Introduction to Membership
Implementing a MembershipProvider
ASP.NET Profile Providers
You could also implement a custom identity. They are very easy to implement, and they let you store whatever user information you want in Identity, which is then stored in the cookies that Identity puts down, so you're not hitting the DB every time to get that info.
Just create a new class that inherits from GenericIdentity, and you'll be on your way.
You of course have to be careful how much info you put there since it's in a cookie, but usually user related information in the case you're talking about here isn't so big.
We use a custom identity to store a few bits of info about the user, and it works out pretty well.
You could store an object in session that holds all the required user information. You will just need to add a property in the Controllers, Views or other base classes where you want to retrieve the user information/profile. This would be the authorisation info as opposed to any authentication info (eg Forms authentication)
You might try "Windows Identity Foundation". I've been using it on one of my projects for a while. It allows for "claims-based authentication", which basically means that you get to designate "claims", strings of information that describe the user when she logs on.
Once logged on, the user's claims can be read from the HttpContext.Current.User field. You can also use "Role" claims that seamlessly integrate with a role-based authentication schema; meaning that you can give the user a "manager" role claim and then use `if (User.IsInRole("manager")).
As an added bonus, WIF makes it very easy to re-use your login screen in other applications.
All in all, it's very flexible, but the documentation is very poor. I've asked and answered a number of questions about "Windows Identity Foundation" on StackOverflow.
We have done this quite a few times in the past. Similar to what Thomas mentions, what we have generally done is implemented a new Membership provider based on the Microsoft SQL Memberhsip provider to do this. We inherit from the base MembershipUser class and add any custom properties we would want to have on the user object. You have to implement a database read for the Membership provider on the GetUser implementation, so you can consolidate your extra properties you need into that database read.
If you are using SQL server, Microsoft has release the 2.0 code for it. You can get more information at Scott Gu's blog.
http://weblogs.asp.net/scottgu/archive/2006/04/13/442772.aspx
If you want to start from scratch, they also have good resources at MSDN.
http://msdn.microsoft.com/en-us/library/f1kyba5e.aspx
and
http://msdn.microsoft.com/en-us/library/6tc47t75.aspx
Once you have implemented your provider, you can then add the Membership user to the Items collection of the current web context to get access to it from your code. The non extended properties from the base base user class are also available on the Request thread like normal.
With the Microsoft release of the 2.0 version of the source code , we found it helped us alleviate some concerns that exist about reinventing. Another thing to consider for your implementations is based on your scenario, you can bypass implementing some of the code. An example of this would be the CreateUser code if you are hitting a back end system that already has the credential information.
It seems like you're relatively happy with your authentication process but you want to explore other options for session/settings.
My suggestion has to do with settings only (roles, preferences, etc.)
In my opinion, having to traverse the whole technology stack from UI to Business Tier to DB tier to DB is sometimes a bit overkill.
For data that isn't likely to change during a session, this adds a lot of overhead... There are potentially several data transformations happening (DB (Relational Format) -> ORM -> Web Service XML Serialization -> Web Tier deserialization).
You might consider a session system that doesn't rely on a heavy RDBMS system or on the ASP.NET Caching / Session model. There are options that are very performant and that scale well.
You could use RavenDB by Ayende Rahien (Built for .NET). Its main goal is to provide low latency, high performance access to schema-less JSON documents.
Using this solution, you would set up ravenDB in the web tier so that access to data is very quick.
The first time you authenticate and retrieve settings, you would store the userID and settings information in this session DB.
Every time you load your controller after that, the settings data is accessible without having to go back to the RDBMS.
This DB could also be used to cache other web related data.
As for security, the settings data makes it to the web tier regardless of the method you use. This solution would be no more or less secure than the other options (more secure than an unencrypted cookie). If you needed to, you could encrypt the session data - but that will increase your overhead again.
Just another one of the million options to consider.
Good Luck,
Let us know what you decide!
Patrick.
I am creating an Asp.net MVC application and I'm currently using the built in Authentication/Authorization code that comes with the sample MVC app. For the most part this is working ok and I kinda understand what's going on.
What's concerning me though, is that now I kind of have my users stored in two different tables across two databases. i.e. I have users in my App's database that represent the "Customer" entity in the application, as well as the "User" in the Authentication database that's used to log in someone to the app.
Should I take the logged in user's User.Identity.Name value and do look up in my Customers table or should I merge them into one table? What's the best practice way of handling this?
Please forgive my ignorance - this is the first time I'm working with a system like this.
Any feedback is greatly appreciated!
It's helpful to think of credentials and the records that associate a person to application data as two very different things. Depending on the application, your Customer may not have credentials to log in or you may have an administrative User that logs in but isn't related to your application data.
Separate credentials are also useful if Users access more than one application with different rights for each.
For these reasons, I'd keep Customer and User separate and look one up from the other where appropriate.
You can extend the .Net Membership Provider to take all the information you want and post back in a single model I think.
See this one ASP.net Profiles and Membership - Custom Providers or should completely I roll my own?
And this one How to implement ASP.NET membership provider in my domain model