I have a following method in my command handler that gets variables from another method,im trying to pass those variable into the CreateUser(NewAccount); method but it always comes back as null
public async Task ExecuteAsync(CreateUserAccountCommand command)
{
var result = await _client.CreateUser(GetAccountFrom(command)); // so this line gets the variables from GetAccountFrom(command)
_httpContextAccessor.HttpContext.Items["CreateUserAccountCommand"] = result;
}
private Account GetAccountFrom(CreateUserAccountCommand command)
{
var NewAccount = new Account();
NewAccount.FirstName = command.FirstName;
NewAccount.LastName = command.LastName;
return NewAccount()
}
however when i call CreateUser to pass in the variables into NewAccount thats coming from GetAccountFrom(command) it passes it in as a null
public System.Threading.Tasks.Task<Account> CreateUser(Account NewAccount,)
{
return base.Channel.CreateUser(NewAccount);
}
What am i doing wrong?
You are creating a new instance of NewAccount in your return statement.
private Account GetAccountFrom(CreateUserAccountCommand command)
{
var newAccount = new Account();
newAccount.FirstName = command.FirstName;
newAccount.LastName = command.LastName;
return newAccount; // <- Return the variable
}
You are creating object with new keyword. All you need to do is to return this object from your method with simple call:
return NewAccount;
The way you do it now is that you are returning result of NewAccount() method (whatever it is, apparently null), which is not what you want.
Also you might want to inspect why NewAccount() returns always null.
Your code has many anti patterns but it seems like you have a method somewhere in the base newAccount(); This is why inheritance should be avoided (for beginners and mids)
also the convention for private local variables lowercase.. as to NOT CONFUSE yourself.
private Account GetAccountFrom(CreateUserAccountCommand command)
{
var newAccount = new Account();
newAccount.FirstName = command.FirstName;
newAccount.LastName = command.LastName;
return newAccount;
}
or to completely avoid confusion just do this
private Account GetAccountFrom(CreateUserAccountCommand command)
{
return new Account{
FirstName = command.FirstName,
LastName = command.LastName,
}
}
But to avoid anti-patterns and spaghetti code you should really make an extension method which is much more S.O.L.I.D !
namespace you.company
{
public static CommandExtensions{
public static Account GetAccountFrom(this CreateUserAccountCommand command)
{
return new Account
{
FirstName = command.FirstName,
LastName = command.LastName,
};
}
}
Related
I have these two methods:
public MessagesPage(ContactModel input)
{
InitializeComponent();
NavigationPage.SetHasNavigationBar(this, false);
ConversationsList = new ObservableCollection<ConversationModel>();
ContactModel ConversationPartner = new ContactModel();
ConversationPartner = input;
...
}
And the input which is the parameter in the method above, I also would like to use it in this method (they're in the same class)
private async void Send()
{
Guid guid = Guid.NewGuid();
string ID = guid.ToString();
ConversationModel conversationObject = new ConversationModel()
{
id = ID,
converseeID = dataClass.loggedInUser.uid,
message = Message,
created_at = DateTime.UtcNow
};
await CrossCloudFirestore.Current
.Instance
.GetCollection("contacts")
.GetDocument(ConversationPartner.id)
.GetCollection("conversations")
.GetDocument(ID)
.SetDataAsync(conversationObject);
Message = string.Empty;
}
because as you can see, in .GetDocument, it needs the id of ConversationPartner. I would get object reference not set to an instance of an object when the Send() method is called because it doesn't have access to ContactModel input in MessagesPage above.
you need to declare ConversationPartner as a class level variable, not inside of of a specific method. This will make it available throughout your class
ContactModel ConversationPartner;
public MessagesPage(ContactModel input)
{
InitializeComponent();
NavigationPage.SetHasNavigationBar(this, false);
ConversationsList = new ObservableCollection<ConversationModel>();
ConversationPartner = input;
...
}
I've posted a similar question (and answered) previously but I've realised I still have a missing piece of the puzzle when passing a method into another method. My question is when passing a method as a parameter how can you include parameters? I've included an example below.
Any help much appreciated.
Many thanks,
Service call
private readonly MemberRepo _memberRepo;
public SomeService()
{
_memberRepo = new MemberRepo();
}
public string GetMembers(int id)
{
// This works, i.e. the RunMethod internally calls the Get method on the repo class - problem: how can I pass the id into the repo Get method?
var result = RunMethod(_memberRepo.Get);
...
return stuff;
}
private string RunMethod(Func<int, string> methodToRun)
{
var id = 10; // this is a hack - how can I pass this in?
var result = methodToRun(id);
..
}
Repository
public class MemberRepo
{
public string Get(int id)
{
return "Member from repository";
}
}
Update
private string RunMethod(Func<int, string> methodToRun)
{
if(id.Equals(1))
{
// Do something
//
var result = methodToRun(id);
..
}
Just pass a second argument to the RunMethod method:
private string RunMethod(Func<int, string> methodToRun, int id)
{
var result = methodToRun(id);
..
}
You can always make id have an optional input as well if needed:
int id= 10
You can pass a lambda function that performs whatever actions you want:
var result = RunMethod(_ => _memberRepo.Get(10));
This makes the int part of the method signature pretty meaningless, so if you have the ability to change your RunMethod() signature, you can do this:
private string RunMethod(Func<string> methodToRun)
{
var result = methodToRun();
..
}
then this:
var result = RunMethod(() => _memberRepo.Get(10));
Update if you need to be able to access the parameter within your RunMethod() method, then just pass it as a separate parameter as TheLethalCoder suggests:
private string RunMethod(Func<int, string> methodToRun, int id)
{
if(id.Equals(1))
{
// Do something
//
var result = methodToRun(id);
..
}
and
var result = RunMethod(memberRepo.Get, 10);
Currently I'm writing a wizard (using MBG SimpleWizard library). I have several pages. and as a way of sharing data between them, they are passed a class out DBManip DBController. I need to use this DBController in a method, but the call is handled by the library and so I can't easily pass DBController by reference to the method. How can I make the passed reference into a property that the method can modify, and preserve the reference.
Class Initialization:
WizardHost host = new WizardHost();
using (host)
{
host.Text = Migration.Properties.Resources.AppName;
host.ShowFirstButton = false;
host.ShowLastButton = false;
host.WizardCompleted += new WizardHost.WizardCompletedEventHandler(this.Host_WizardCompleted);
DBManip DBController;
host.WizardPages.Add(1, new Page1());
host.WizardPages.Add(2, new Page2(out DBController));
host.WizardPages.Add(3, new Page3(out DBController));
host.WizardPages.Add(4, new Page4(out DBController));
host.LoadWizard();
host.ShowDialog();
}
Constructor:
public Page2(out DBManip DBController)
{
this.InitializeComponent();
this.label1.Text = Migration.Properties.Resources.ExportDirectoryMessage;
this.exportDirTextbox.Text = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
}
Method:
private bool SetExportDirectory ()
{
string exportDirectory = this.exportDirTextbox.Text;
// If a path is given, check if it's valid
// and set the pathExists boolean
if (!Directory.Exists(exportDirectory))
{
MessageBox.Show(Migration.Properties.Resources.InvalidPath);
return false;
}
// Initializing the object to manipulate the databases
exportDirectory = new DBManip(exportDirectory);
return true;
}
Property which will call method:
public bool PageValid
{
get { return SetExportDirectory(); }
}
Sorry if I'm missing something simple, I'm fairly new to C#
It's not clear what your pages are doing with DBManip, but you'll need to have it as a property of any Page class that uses it.
To do that, you'd ordinarily create an instance of DBManip first before creating the pages, and pass it to each constructor that wants it. Each of those classes will have a property where it stores the reference so it can use it later. Each class will need to declare that property for itself, since you're not easily going to be able to give them a common base class of your own.
But you're creating it later. Since you need the different classes to share a reference to an object that's created after their constructors exit, we'll add a quickie "reference" generic class, and they'll all share a reference to that. Then we can change its properties, and they'll all have the new property values on the existing instance of this little "handle" class.
Reference.cs
// Semantically, this is basically a pointer to a pointer, without the asterisks.
public class Reference<T>
{
public Reference() { }
public Reference(T t) { Value = t; }
public T Value;
}
Main C#
WizardHost host = new WizardHost();
using (host)
{
host.Text = Migration.Properties.Resources.AppName;
host.ShowFirstButton = false;
host.ShowLastButton = false;
host.WizardCompleted += new WizardHost.WizardCompletedEventHandler(this.Host_WizardCompleted);
// ************************
// Create shared "reference" instance
// ************************
Reference<DBManip> dbControllerRef = new Reference<DBManip>();
host.WizardPages.Add(1, new Page1());
host.WizardPages.Add(2, new Page2(dbControllerRef));
host.WizardPages.Add(3, new Page3(dbControllerRef));
host.WizardPages.Add(4, new Page4(dbControllerRef));
host.LoadWizard();
host.ShowDialog();
}
Page2.cs
// It's not an out parameter so don't make it one.
public Page2(Reference<DBManip> dbControllerRef)
{
this.InitializeComponent();
this.DBControllerRef = dbControllerRef;
this.label1.Text =
Migration.Properties.Resources.ExportDirectoryMessage;
this.exportDirTextbox.Text =
Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
}
public Reference<DBManip> DBControllerRef {
get; private set;
}
private bool SetExportDirectory ()
{
string exportDirectory = this.exportDirTextbox.Text;
// If a path is given, check if it's valid
// and set the pathExists boolean
if (!Directory.Exists(exportDirectory))
{
MessageBox.Show(Migration.Properties.Resources.InvalidPath);
return false;
}
// Everybody has the same Refernece<DBManip>
this.DBControllerRef.Value = new DBManip(exportDirectory);
return true;
}
I need a Login function(login is just an example, any other frequently used method can be fine) which takes email and password as parameter and asks DB if there is such a user. If yes, it has to return customer_id(int), if no, it will return the message why login could not happen(ex:no such an email address).
I also do not wanna rewrite the login function everytime. I want to write it once in a common project which I can use in my every project and reuse it. But i am trying to find out the best practice for this. So far, i thought something like below, but the problem for me is that i cannot return customerID which i will get in codebehind in my projects(any other project) and open a session variable with it. I only can return strings in below structure. I also thought returning a Dic, but this also is wrong I guess because if bool(key) happens to be true, customerID is not a string(value). Can you help me please learning the correct way of using common functions with no need to think the returning messages and variables twice? Thanks a lot
public class UserFunctions
{
private enum Info
{
//thought of returning codes??
LoginSuccess = 401,
NoMatchPasswordEmail = 402,
InvalidEmail = 403,
};
public string TryLogin(string email, string password)
{
bool isValidEmail = Validation.ValidEmail(email);
if (isValidEmail == false)
{
return Result(Info.InvalidEmail);
// returning a message here
}
Customers customer = new Customers();
customer.email = email;
customer.password = password;
DataTable dtCustomer = customer.SelectExisting();
if (dtCustomer.Rows.Count > 0)
{
int customerID = int.Parse(dtCustomer.Rows[0]["CustomerID"].ToString());
return Result(Info.LoginSuccess);
// Here I cant return the customerID. I dont wanna open a session here because this function has no such a job. Its other projects button events job I guess
}
else
{
return Result(Info.NoMatchPasswordEmail);
}
}
private string Result(Info input)
{
switch (input)
{
case Info.NoMatchPasswordEmail:
return "Email ve şifre bilgisi uyuşmamaktadır";
case Info.InvalidEmail:
return "Geçerli bir email adresi girmelisiniz";
case Info.LoginSuccess:
return "Başarılı Login";
}
return "";
}
}
You may want to consider returning an instance of a custom class.
public class LoginResult
{
public Info Result { get; set; }
public int CustomerId { get; set;}
}
Modify your TryLogin method to return an instance of LoginResult.
Base your application flow on the result:
var loginResult = TryLogin(..., ...);
switch (loginResult.Result)
{
case Info.LoginSuccess:
var customerId = loginResult.CustomerId;
//do your duty
break;
case Info.NoMatchPasswordEmail:
//Yell at them
break;
...
}
You could try Creating an event and then the calling code can register to the event before attempting to login.
For example:
public class UserFunctions
{
private enum Info
{
LoginSuccess = 401,
NoMatchPasswordEmail = 402,
InvalidEmail = 403,
};
public delegate void LoginAttemptArgs(object sender, Info result, int CustomerID);//Define the delegate paramters to pass to the objects registered to the event.
public event LoginAttemptArgs LoginAttempt;//The event name and what delegate to use.
public void TryLogin(string email, string password)
{
bool isValidEmail = Validation.ValidEmail(email);
if (isValidEmail == false)
{
OnLoginAttempt(Info.InvalidEmail, -1);
}
Customers customer = new Customers();
customer.email = email;
customer.password = password;
DataTable dtCustomer = customer.SelectExisting();
if (dtCustomer.Rows.Count > 0)
{
int customerID = int.Parse(dtCustomer.Rows[0]["CustomerID"].ToString());
OnLoginAttempt(Info.LoginSuccess, customerID);
}
else
{
OnLoginAttempt(Info.NoMatchPasswordEmail, -1);
}
}
private void OnLoginAttempt(Info info, int CustomerID)
{
if (LoginAttempt != null)//If something has registered to this event
LoginAttempt(this, info, CustomerID);
}
}
I wouldn't compile a string to return, I would return the enum result and let the calling code do what it likes with the result. reading an enum is much quicker than parsing returned string.
Edit: Typos and i missed an event call... .Twice
I am trying to experiment with RhinoMocks, where I have to say I am a newbie and probably I don't get some obvious thing here. What I'm doing is something like :
[TestMethod]
public void SaveResponsibleUserFromChangeset()
{
var action = mocks.StrictMock<GenomeAction>();
var changeset = new ActionChangeset();
changeset.ResponsibleUser = new ChangeableProperty<UserIdentity>("Administrator") {IsChanged = true};
changeset.MarkAll(true);
using(mocks.Record())
{
Expect.Call(action.ResponsibleUser).SetPropertyAndIgnoreArgument();
}
using(mocks.Playback())
{
var persistor = new ActionPersistor(new MockIdentityResolver());
persistor.SaveActionChanges(changeset, action);
}
action.VerifyAllExpectations();
}
private class MockIdentityResolver : IIdentityResolver
{
public GenomeUser GetUser(UserIdentity identity)
{
var user = mocks.DynamicMock<GenomeUser>();
user.Username = identity.Username;
return user;
}
}
The intention is to have a very simple test which checks whether the SaveActionChanges method sets the ResponsibleUser property. As a part of this, it needs to resolve the user identity using the resolver, for which I have provided a mock implementation. Unfortunately, it seems I can't just return back another mock within the Playback mode, because it says (on the closing bracket of the second using) that The action is invalid when the object (of type GenomeUser) is in record state.
Any ideas of what is causing the trouble and how to overcome it ?
I think you need to create you new MockIdentityResolver() outside the mocks.Playback().
[TestMethod]
public void SaveResponsibleUserFromChangeset()
{
var action = mocks.StrictMock<GenomeAction>();
var changeset = new ActionChangeset();
var identityResolver;
changeset.ResponsibleUser = new ChangeableProperty<UserIdentity>("Administrator") {IsChanged = true};
changeset.MarkAll(true);
using(mocks.Record())
{
Expect.Call(action.ResponsibleUser).SetPropertyAndIgnoreArgument();
identityResolver = new MockIdentityResolver()
}
using(mocks.Playback())
{
var persistor = new ActionPersistor(identityResolver);
persistor.SaveActionChanges(changeset, action);
}
action.VerifyAllExpectations();
}
private class MockIdentityResolver : IIdentityResolver
{
public GenomeUser GetUser(UserIdentity identity)
{
var user = mocks.DynamicMock<GenomeUser>();
user.Username = identity.Username;
return user;
}
}
you should look at using the AAA syntax, it seems to be generally accepted that it's a clearer way of using stuff.