GAE with Datastore (JDO) - google-cloud-datastore

I am new to GAE and especially for Datastore (JDO)
I have an Object Composition : User object has a reference of Contact object.
I am able to store them in datastore. But the code allows to store multiple objects with same “username” which is defined as primary key.
Here is the code snippet
//User class
#PersistenceCapable (identityType = IdentityType.APPLICATION)
public class User{
#PrimaryKey
#Persistent (valueStrategy = IdGeneratorStrategy.IDENTITY)
String username;
#Persistent
Contact contact;
//getters and setters
}
// Contact class
#PersistenceCapable (identityType = IdentityType.APPLICATION)
public class Contact {
#PrimaryKey
#Persistent (valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key username;
#Persistent
String Phone1;
}
//DAO class
public void register() {
User user = new User();
user.setUserName("abc");
Contact contact=new Contact();
contact.setEmail("abc#gmail.com");
user.setContact(contact);
pm.makePersistent(user);
}
If I call this register method twice (or equivalent to submit a registration form twice with same set of username and email id), the datastore is not complaining about duplicate key Exception.
Since I am creating "username" as my KEY I am expecting to get duplicate key Exception. But why is this not happening?
thanks
Ma

What "same set of username and email" ? You set username to be autogenerated, by JDO, so it generates the value for that field not you. Consequently it is unique. Consequently there is no exception.

Related

How to get current user id, if i inherits from IdentityUser?

I add some fields in IdentityUser like a
public class CustomUser: IdentityUser
{
public string field1 {get;set;}
public string field2 {get;set;}
}
after migration, on Sql Management studio i had all data, which i added with .OnModelCreating
But, How i can get any field from current authorized CustomUser (like a ID)
I try use
using Microsoft.AspNet.Identity;
CustomUser.Identity.GetUserId()
But it doesnt work.
Thanks for help!
In ASP.Net Core ,if your Controller inherits the Microsoft.AspNetCore.Mvc.Controller, you could get the IClaimsPrincipal from the User property and get the actual "Id" of the user,
using System.Security.Claims;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
ClaimsPrincipal currentUser = this.User;
var currentUserID = currentUser.FindFirst(ClaimTypes.NameIdentifier).Value;
You can also get the data of all fields(include Id) from the database's User entity:
1.DI UserManager
private readonly UserManager<ApplicationUser> _userManager;
public HomeController(UserManager<ApplicationUser> userManager)
{
_userManager = userManager;
}
2.Use it like below:
var id = userManager.GetUserId(User); // get user Id
var user = await userManager.GetUserAsync(User); // get user's all data
You need to first save user data in claims and then get authorized user data.
Add Claims
var identity = new ClaimsIdentity(OAuthDefaults.AuthenticationType);
identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, user.Id.ToString()));
Get Claims
var userId = (HttpContext.Current.User.Identity as ClaimsIdentity).Claims.FirstOrDefault(x => x.Type == ClaimTypes.NameIdentifier)

How do you add a new user and claim in a single transaction using ASP.NET Core 2.1 Identity?

I am trying to add a new user and some other associated entities including a claim as one transaction. My classes are basically defined as below. Note that I am using int primary keys on my User class and that it is an identity column (value is provided by the database on insertion).
public class User : IdentityUser<int>
{
// custom props here
}
public class UserClaim : IdentityUserClaim<int>
{
// i actually haven't added anything to this class, it's mainly here so
// i don't have to keep specifying the user's primary key type
}
public class OtherEntity
{
public int UserId { get; set; }
[ForeignKey(nameof(UserId))]
public User User { get; set; }
// other stuff
}
I then want to add the user etc. to the database something like this:
User user = new User(){ /* set props */ };
OtherEntity other = new OtherEntity()
{
User = user
};
UserClaim claim = new UserClaim()
{
/* this is where the problem is */
UserId = user.Id,
ClaimType = "my-claim-type",
ClaimValue = "my-claim-value"
};
context.AddRange(user, other, claim);
context.SaveChanges();
I can easily link the User to the OtherEntity because I have set up the navigation property so I can just add the User to it and entity framework takes care of the filling in the UserId column. I cannot do this with UserClaim because it doesn't have the navigation property. I could call context.SaveChanges() after adding the User and entity framework would get the User.Id created by the database for me which I could use to set UserId on the UserClaim, but that would mean two transactions.
I have tried adding the navigation property to my definition of UserClaim as follows:
public class UserClaim : IdentityUserClaim<int>
{
[ForeignKey(nameof(UserId))]
public User User { get; set; }
}
But I get following runtime error:
InvalidOperationException: The relationship from 'UserClaim.User' to 'User' with foreign key properties {'UserId' : int} cannot target the primary key {'Id' : int} because it is not compatible. Configure a principal key or a set of compatible foreign key properties for this relationship.
Is there a way of creating both the user, and the claim in the same transaction?
My question should have been: "How do I add navigation properties between ASP.NET Identity classes?"
If I had looked for the answer to that I would have found the microsoft docs explaining how to do it!
The docs linked above tell you how to add the User.UserClaims navigation property:
public class User : IdentityUser<int>
{
public virtual ICollection<UserClaim> Claims { get; set; }
}
public class DataContext : IdentityDbContext</* Identity classes */>
{
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<User>(e =>
{
e.HasMany(u => u.Claims)
.WithOne()
.HasForeignKey(c => c.UserId)
.IsRequired();
});
}
}
But it doesn't show how to make the reverse UserClaim.User navigation property. I worked out that this can be done like this:
public class UserClaim : IdentityUserClaim<int>
{
public virtual User User { get; set; }
}
public class DataContext : IdentityDbContext</* Identity classes */>
{
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<User>(e =>
{
e.HasMany(u => u.Claims)
.WithOne(c => c.User) // <- this line is different
.HasForeignKey(c => c.UserId)
.IsRequired();
});
}
}
You can then create a new user and claim at the same time as per my question:
User user = new User(){ /* set props */ };
UserClaim claim = new UserClaim()
{
User = user, // <- this is the bit you can't do without the nav. property
ClaimType = "my-claim-type",
ClaimValue = "my-claim-value"
};
context.AddRange(user, claim);
context.SaveChanges();
I guess it's common sense, though I didn't realise until I inspected the actual SQL hitting the database, but this will still require two trips to the database even though we are only calling .SaveChanges() once! Entity Framework will first save the User and get the ID for the inserted row which it will then use when inserting the UserClaim.
Inserting related data is documented in Entity Framework: https://learn.microsoft.com/pl-pl/ef/core/saving/related-data
And it is also well described in other topics, for example: Entity Framework Foreign Key Inserts with Auto-Id
Every of you entites need to be set correctly for relations (foreign keys) in your entites models (without them, EF don't know what to do) and when you are adding it, you need to start from beginning, so UserClaim must be set from your User entity, for example
var user = new User(){
//properites
OtherEntity = new OtherEntity()
{
Id = 0, /*will be set automatically*/
UserId = 0 /*will be set automatically*/
/* other properites */
};
Claim = new UserClaim(){
Id = 0, /*will be set automatically*/
UserId = 0 /*will be set automatically*/
/* other properites */
}
}
ontext.Add(user);
context.SaveChanges();
You didn't provide all the information about your relations, I've just assumed this from your code.
PS. AddRange has only one parameter.
EDIT:
To clarify my answer, for everything to work, AddRange/Add need to be called with your base entity and relations inside, in tree manner.
But first you need to configure your models, something like that.
public class User : IdentityUser<int>
{
[ForeignKey("UserClaimId")]
public virtual UserClaim Claim {get;set;}
}
public class UserClaim : IdentityUserClaim<int>
{
[ForeignKey("UserId")]
public virtual User User {get;set;}
}
public class OtherEntity
{
public int UserId { get; set; }
[ForeignKey("UserId")]
public User User { get; set; }
// other stuff
}
You can also use OnModelCreating to set up entites, as described in documentation: https://learn.microsoft.com/en-us/ef/core/modeling/relationships
Entity Framework right now don't know anything about relations in Database, data types etc.
Updated code example
Edit, don't have enough reputation to add comment to your answer
Well, EF still needs to track entities. I would need to write and run some examples to check if there is some way to improve trips to database. Maybe someone could tell you more about mechanism that is behind adding related-data and if there is a way to improve it.
There are some libraries that helps with improving performance of saving changes to database, for example: https://entityframework-extensions.net
You could try it.

asp.net ef code first duplicate elements with foreign key

I have the following code :
public Exam CreateExam(string name, List<Question> questions, DateTime timeNow)
{
User user = GetUserByName(name);
Exam exam = new Exam()
{
Questions = questions,
StartDate = timeNow,
User = user
};
Context.Exams.Add(exam);
Context.SaveChanges();
return exam;
}
Exam :
public class Exam
{
public int Id { get; set; }
public DateTime StartDate { get; set; }
public User User { get; set; }
public virtual List<Question> Questions { get; set; }
}
And user has the basic user infos.
My problem is that when I create an exam for the user, the save change also add a new user to the database, with only the ID being different. How do I prevent that and make it understand that I want to link it to the existing user ?
Thank you !
Edit: GetUserByName() :
Context.Database.SqlQuery<User>("Select * from Users where name = #name", new SqlParameter("name", name)).FirstOrDefault();
When you use SqlQuery to fetch user, he will not be tracked by Entity Framework, because you can write arbitrary query and map result to User class. So EF consider, that he is new one, when you reference to him. To fix this problem, you should manually attach his to context:
User user = GetUserByName(name);
Context.Users.Attach(user);
Based Slava Utesinov answer Entity Framework's change tracker does not track entity changes when get from raw query such as:
Context.Database.SqlQuery<User>("Select * from Users where name = #name", new SqlParameter("name", name)).FirstOrDefault();
Therefore when you call SaveChanges() method, Entity Framework change tracker detect user entity state as Added (new entity)
1.you can use DbSet.SqlQuery instead of Database.SqlQuery because DbSet.SqlQuery will tracked by the context:
Context.Users.SqlQuery("Select * from Users where name = #name", new SqlParameter("name", name)).FirstOrDefault();
or
2.you can attach entity to current context dbset as unchanged state

How to access token additionalInformation to validate expression-based access control

I succesfully added user_id additionnal information on the generated tokens on the authorization server side by implementing a TokenEnhancer. Here is a token generated:
{"access_token":"ccae1713-00d4-49c2-adbf-e699c525d53e","token_type":"bearer","expires_in":31512,"scope":"end-user","user_id":2}
Now, on the Resource server side, which is a completely separate spring project communicating through a RemoteTokenServices, i would like to use theses informations with method expression-based access control. For example i would like to use the added user_id data (it is Spring Data JPA repository for use with Spring Data Rest):
#PreAuthorize("#oauth2.hasScope('admin') or #id == authentication.principal.user_id")
#Override
UserAccount findOne (#P("id") Integer id);
The #oauth2.hasScope('admin') works as expected but the #id == authentication.principal.user_id" part obviously not.
how can i access to the additional data added to the token on expression-based access control ?
So i've found myself. The key interface is UserAuthenticationConverter.
Using the default provided DefaultUserAuthenticationConverter class, we can set a UserDetailsService which is used to set authentication.principal with the UserDetail object returned by the UserDetailsService. Without that, authentication.principal is only set with the token username as a String.
Here is an extract of my ResourceServerConfigAdapter:
#Configuration
#EnableResourceServer
protected static class ResourceServerConfiguration
extends ResourceServerConfigurerAdapter {
#Bean
UserDetailsService userDetailsService () {
return new UserDetailsServiceImpl();
}
#Bean
public UserAuthenticationConverter userAuthenticationConverter () {
DefaultUserAuthenticationConverter duac
= new DefaultUserAuthenticationConverter();
duac.setUserDetailsService(userDetailsService());
return duac;
}
#Bean
public AccessTokenConverter accessTokenConverter() {
DefaultAccessTokenConverter datc
= new DefaultAccessTokenConverter();
datc.setUserTokenConverter(userAuthenticationConverter());
return datc;
}
#Bean
RemoteTokenServices getRemoteTokenServices () {
RemoteTokenServices rts = new RemoteTokenServices();
rts.setCheckTokenEndpointUrl(
"http://localhost:15574/oauth/check_token");
rts.setAccessTokenConverter(accessTokenConverter());
rts.setClientId("client");
rts.setClientSecret("pass");
return rts;
}
...
}
Another method is to override the DefaultUserAuthenticationManager and provide a custom public Authentication extractAuthentication(Map<String, ?> map).
Once this is done, we can use the user data on expression-based access control like that:
#PreAuthorize("#oauth2.hasScope('admin') or #id == authentication.principal.userAccount.id")
#Override
UserAccount findOne (#P("id") Integer id);
Note that userAccount is my original DOMAIN user object. It could be everything the UserDetailsService returns.
EDIT:
To answer to Valentin Despa, here is my UserDetailsService implementation:
#Component
public class UserDetailsServiceImpl implements UserDetailsService {
#Autowired
UserAccountRepository userAccountRepository;
public UserDetails loadUserByUsername (String username)
throws UsernameNotFoundException {
// Fetch user from repository
UserAccount ua = this.userAccountRepository
.findByEmail(username);
// If nothing throws Exception
if (ua == null) {
throw new UsernameNotFoundException(
"No user found having this username");
}
// Convert it to a UserDetails object
return new UserDetailsImpl(ua);
}
}

What Type (class) do i use for a property in my POCO for Asp.net Identy User

I have a codefirst POCO, and i want to specify a LastEditUser from my current ASP.NET IDENTITY user. I tried type ApplicationUser that gets generated with the new project. but it just saves as null.
Here is my current Attempt
public class SomeClass
{
public string SomeProperty { get; set; }
public ApplicationUser LastEditMember { get; set; }
}
And here is how i try to save it in my controller.
string currentUserId = User.Identity.GetUserId();
ApplicationUser currentUser = db.Users.FirstOrDefault(x => x.Id == currentUserId);
instannceOfSomeClass.LastEditMember = currentUser;
After loading this again. the LastEditMember property is null.
I would suggest using the UserManager class to get the user object instead of working with the DbContext object. You can use UserManager.FindByIdAsync(currentUserId) to get the user. Also I am considering that this code is hit only after a user logs into the application else the currentUserId will be null

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