LSL.DbConfigurationProvider 1.0.10

LSL.DbConfigurationProvider

Provides a ConfigurationProvider that reads settings from a database table.

Configuring with the default settings

The following example sets up a DB configuration provider that fetches the settings from a table called Settings with a key field called Key and a value field called Value.

var builder = new ConfigurationBuilder();
builder.AddDbConfiguration(
    () => new SqlConnection("my-connection-string"));

Configuring with the custom settings

The following example sets up a DB configuration provider that fetches the settings from a table called OtherSettings with a key field called OtherKey and a value field called OtherValue.

var builder = new ConfigurationBuilder();
builder.AddDbConfiguration(
    () => new SqlConnection("my-connection-string"), 
    "OtherSettings", 
    "OtherKey", 
    "OtherValue");

Configuring with a key prefix

The following example sets up a DB configuration provider that only fetches settings whose keys are prefixed with the value of the keyPrefix parameter.

var builder = new ConfigurationBuilder();
builder.AddDbConfiguration(
    () => new SqlConnection("my-connection-string"), 
    keyPrefix: "my-application:");

All returned settings will have the prefix automatically removed from the key name.

Dealing with errors on load

An optional paramter onLoadError allows for the passing of a delegate to decide what to do when an error occurs on loading settings from the DB.

var builder = new ConfigurationBuilder();
builder.AddDbConfiguration(
    () => new SqlConnection("my-connection-string"), 
    onLoadError: context =>
    {
        Console.WriteLine(context.Exception.ToString());

        // NOTE: The following is not required really
        // as RethrowException defaults to false.
        // It is set here only to show that this is an option.
        context.RethrowException = false;
    });

onLoadError Context

The onLoadError delegate is passed a context that has the following members available:

Exception

This readonly property provides the exception that was thrown so that an error handler can act appropriately based on what was thrown.

RethrowException

This property defaults to false but can be set to true in order to throw an exception of type DbConfigurationProviderLoadException so that a consuming application can react to the problem and inspect the InnerException and act accordingly.

NOTE: The InnerException is the instance of the originally thrown exception.