CODEWITHSUNDEEP
c#dependency-injectionninject
Daniel Schobel
Daniel Schobel

Reputation: 506

Binding recurring connection string constructor parameters using DI

I'm looking for advice on how best to bind a couple of connection strings which recur throughout my dependencies.

Currently I have (using ninject): 

Bind<IFoo>().To<SqlFoo>()
.WithConstructorArgument("db1ConnStr", db1ConnectionString)
.WithConstructorArgument("db2ConnStr", db2ConnectionString);

Bind<IBar>().To<SqlBar>()
.WithConstructorArgument("db1ConnStr", db1ConnectionString)
.WithConstructorArgument("db2ConnStr", db2ConnectionString);

etc.

which obviously is not the most elegant code.

Is there a way to bind the value of db1ConnectionString to every string constructor parameter named "db1ConnStr"?

Upvotes: 1

Views: 208

Answers (1)

nemesv
nemesv

Reputation: 139758

I would create a class which holds the connection strings:

public class ConnectionStringProvider
{
    public string Db1ConnectionString { get; set; }
    public string Db2ConnectionString { get; set; }
}

Note: You can also create an interface IConnectionStringProvider for it if you want.

Then the classes SqlFoo and SqlBar can use it as a dependency

public class SqlFoo
{
    public SqlFoo(ConnectionStringProvider connectionStringProvider)
    {
         //do something with connectionStringProvider.Db1ConnectionString 
    }
}

And the registration would look like this:

Bind<ConnectionStringProvider>().ToConstant(
    new ConnectionStringProvider
    {
        Db1ConnectionString = db1ConnectionString,
        Db2ConnectionString = db2ConnectionString,
    });
Bind<IFoo>().To<SqlFoo>();
Bind<IBar>().To<SqlBar>();

Upvotes: 2

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