i need your help
i have app.config like this
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
...
</configSections>
<connectionStrings>
...
</connectionStrings>
<appSettings />
<userSettings>
<MySettings>
<setting name="Precision" serializeAs="String">
<value>0</value>
</setting>
</MySettings>
</userSettings>
<applicationSettings>
...
</applicationSettings>
</configuration>
what I need is to get 'Precision' value. how to get that without looping SectionGroups, SectionCollection?
note:
I've DAL and in my DAL need this precision to format the decimal value and the precision is managed by user(client) through the Presentation Layer. I save the precision value in app.config. The problem, the app.config is in Presentiation Layer, and I cannot use Properties.MySetting.Default.Precision to get that. (Thanks to Branko & Tim to remind me about this reason)
I would consider "settings injection" here - like dependency injection, but for settings :)
Presumably your entry point configures the whole system... so get it to read all the settings from app.config, and use those when creating and configuring the DAL (and anywhere else which needs settings). The only piece of code which needs to know how to use app.config can be the entry point. Everything else can be specified via POCOs, individual constructor parameters etc.
This is good in several ways:
Your code will be easier to test: to test different settings, just pass in different constructor arguments. No need for files etc.
Your immediate problem is solved: the DAL no longer needs to look through the settings file
You're isolating your configuration storage in a single place which can change if you decide to (say) use a different XML format, or an "ini"-style configuration format
If I've understood Jon's answer correctly it looks like the following:
public interface IConfigurationWrapper
{
IDictionary<string, string> Properties { get; }
T GetSection<T>(string name) where T : ConfigurationSection;
}
public class ConfigurationWrapper : IConfigurationWrapper
{
// implementation with with ConfigurationManager.GetSection or just placeholders
}
public interface IProduct
{
string Name { get; }
}
public class Product : IProduct
{
readonly IConfigurationWrapper m_configuration;
public Product(string key, IConfigurationWrapper configuration)
{
m_configuration = configuration;
}
public string Name
{
get { // use m_configuration to get name from .config }
}
}
public class ProductFactory
{
readonly IConfigurationWrapper m_configuration;
public ProductFactory(IConfigurationWrapper configuration)
{
m_configuration = configuration;
}
public IProduct CreateProduct(string key)
{
return new Product(key, m_configuration);
}
}
and usage looks like:
var config = new ConfigurationWrapper();
var factory = new ProductFactory(config);
var product = factory.CreateProduct("myproductkey");
clients work with IProduct interface only, "products" layer works with IConfigurationWrapper, while wrapper works with whatever the configuration you have (.config or mocks, you can have mock products for testing too). Code above is heavily stripped part of larger system just to provide example don't get it too literally.
Related
For some context, I want to open a connection to a database and execute some queries.
Here's my App.config:
<dbservers>
<connectionStrings>
<add name="Cube_ConnectionString" connectionString="OLEDB; Datasource=http://cube.com; Initial Catalog=BP" />
</connectionStrings>
<queries>
<add connectionStringName="CubeConnectionString" usedBy="DataAccessor" connectionString="" />
</queries>
</dbservers>
This is how I intend to retrieve the connectionString:
System.Configuration.ConfigurationManager.ConnectionStrings["Cube_ConnectionString"].ConnectionString;
I am wondering whether GetSection or ConnectionString would be best to use. And what would be returned for both of them? How do these two methods function within nested XML such as this?
Additionally, what's the purpose of putting queries in the app.config?
Thanks in advance
I don't think that ConnectionStrings will work unless you put them in the standard section for those. If you want a custom <dbservers> section, you'll have to use GetSection instead.
This functionality is a bit awkward, but highly useful. How to: Create Custom Configuration Sections Using ConfigurationSection is a useful guide for this.
Essentially this boils down to creating a class that inherits from ConfigurationSection, and adding the proper attributes (from the above guide):
public class PageAppearanceSection : ConfigurationSection
{
// Create a "remoteOnly" attribute.
[ConfigurationProperty("remoteOnly", DefaultValue = "false", IsRequired = false)]
public Boolean RemoteOnly
{
get
{
return (Boolean)this["remoteOnly"];
}
set
{
this["remoteOnly"] = value;
}
}
// Create a "font" element.
[ConfigurationProperty("font")]
public FontElement Font
{
get
{
return (FontElement)this["font"]; }
set
{ this["font"] = value; }
}
// Create a "color element."
[ConfigurationProperty("color")]
public ColorElement Color
{
get
{
return (ColorElement)this["color"];
}
set
{ this["color"] = value; }
}
}
...and then adding a reference to your section in the app/web.config:
<configuration>
<configSections>
<section name="dbservers" type="Namespace.DbServersSection, YourAssembly"/>
</configSections>
</configuration>
I have the following method in my apiController:
public IEnumerable<something> GetData(DataProvider dataProvider)
{
return dataProvider.GetData();
}
What I need is to invoke this method from javascript and pass it a parameter of DataProvider derived type. I can handle this by passing string, e.g. "FirstProvider" and than write N number of if's in GetData() method to create an instance of proper type.
But is there some way that I can write in web.config file something like:
<DataProviders>
<type = FirstDataProvider, alias = "FirstProvider">
<type = SecondDataProvider, alias = "SecondProvider">
</DataProviders>
Change getData method to:
public IEnumerable<something> GetData(string dataProviderAlias)
{
// get provider type by it's alias from web congfig,
// then instantiated and call:
return dataProvider.GetData();
}
And then find and instantiate the type by it's alias?
Note: I accepted the answer below cause it's pointed me in a right direction, but msdn says that IConfigurationSectionHandler is deprecated.
So I used ConfigurationSection, ConfigurationElementCollection, ConfigurationElement classes instead to build custom config section.
You can store arbitrary data in web.config in the appSettings element:
<configuration>
<appSettings>
<add key="FirstAlias" value="FirstProvider" />
<add key="SecondAlias" value="SecondProvider" />
</appSettings>
</configuration>
And you can then read the values using:
String firstAlias = System.Configuration.ConfigurationManager.AppSettings["FirstAlias"];
String secondAlias = System.Configuration.ConfigurationManager.AppSettings["SecondAlias"];
It's built-in. It's supported. It's where you're supposed to store custom data.
First of all, you can only store valid xml in web.config. <type = FirstDataProvider, alias = "FirstProvider"> is not valid xml.
Second, there are a lot of moving pieces. Please follow the steps carefully -
web.config
Make sure you enter the proper namespace for DataProviders. type="YOUR_APPLICATION.DataProviders".
<configuration>
<configSections>
<section name="DataProviders" type="WebApplication2010.DataProviders"
requirePermission="false"/>
</configSections>
<DataProviders>
<Provider type="FirstDataProvider" alias="FirstProvider"/>
<Provider type="SecondDataProvider" alias="SecondProvider"/>
</DataProviders>
....
</configuration>
Code
public class DataProviders : IConfigurationSectionHandler
{
private static bool _initialized;
public static List<Provider> _providers;
public object Create(object parent, object configContext, XmlNode section)
{
XmlNodeList providers = section.SelectNodes("Provider");
_providers = new List<Provider>();
foreach (XmlNode provider in providers)
{
_providers.Add(new Provider
{
Type = provider.Attributes["type"].Value,
Alias = provider.Attributes["alias"].Value,
});
}
return null;
}
public static void Init()
{
if (!_initialized)
{
ConfigurationManager.GetSection("DataProviders");
_initialized = true;
}
}
public static IEnumerable<Provider> GetData(string dataProviderAlias)
{
return _providers.Where(p => p.Alias == dataProviderAlias);
}
}
public class Provider
{
public string Type { get; set; }
public string Alias { get; set; }
}
Global.asax
For good design practice, you want to read data from web.config only once, and store them in static variables. Therefore, you want to initialize inside Application_BeginRequest of Global.asax.
public class Global : System.Web.HttpApplication
{
void Application_BeginRequest(object sender, EventArgs e)
{
DataProviders.Init();
}
}
Usage
var providers = DataProviders.GetData("FirstProvider").ToList();
Well, I'm not sure if I understand what you want to achieve, but to implement your idea you need a custom section handler.
http://msdn.microsoft.com/en-us/library/2tw134k3(v=vs.100).aspx
In case that you want to create a database connection for specific dataprovider, see this similar question:
ASP.NET: How to create a connection from a web.config ConnectionString?
In my case, I needed to store two byte[] variables in my Web.Config file. Since it must be valid XML data, I simply stored the contents of the arrays like so:
<appSettings>
<add key="Array1" value="0,1,2,3,4,5,6,7,8,9" />
<add key="Array2" value="0,1,2,3,4,5,6,7,8,9" />
</appSettings>
I then call a function that reads this into a C# string, split it into a string[], and parse each string element as a byte into a resulting byte[] and return it.
Well, I'm making my foray into this fantastic site with a question about the correct way to inject configuration settings into application components. So, the overview is : I have an application written in C# .Net 3.5. It consists of 3 assemblies - a Core, a Data and a Service. The data & service assemblies require settings retrieved from the app.config, which is done via a settings file, eg.
Code :
public static String RequestQueueConnectionString
{
get { return ConnectionSettings.Default.RequestQueueConnectionString; }
}
Config :
<applicationSettings>
<MyNamespace.Data.ConnectionSettings>
<setting name="RequestQueueConnectionString" serializeAs="String">
...
Now, the assemblies are all setup using StructureMap for IoC - which to my mind should provide the answer to what I am looking for, but I just can't quite see it!
IoC :
public static void ConfigureStructureMap(IContainer container)
{
container.Configure(x => ...
...
What I want to be able to do is to inject a configuration class already populated into the IoC container such that those settings are used for that assembly, NOT those specified in the settings file / app.config. So perhaps :
public static void ConfigureStructureMap(IContainer container, MyConfigClass config)
{
container.Configure(x => x.For<DataConfig>()
.Singleton()
.Use ???
...
I hope I have provided enough details here - forgive a newbie if I have not and please let me know what else would be helpful in answering this!
So, after a lot of searching and trial and error, I was presented with #default.kramer's link, which I duely followed! With a little bit of trial and error, again (best way in my opinion), I managed to get the solution I was looking for. Now, whilst you can follow the link (and I would highly suggest doing so), I am going to post the solution to my question as I implemented it. Hopefully this might help someone with a similar problem.
So, I now have my configuration setup class like so :
public static class DispatchConfiguration
{
public static void ConfigureStructureMap(IContainer container, IDispatchConfiguration dispatchConfig)
{
DispatchProcessBatchSize = dispatchConfig.DispatchProcessBatchSize;
ServiceIsActive = dispatchConfig.ServiceIsActive;
...
}
Now, before I was using a settings file to retrieve the configuration out of the app.config file. This was obviously good for ensuring I had flexibility in changing my config settings, but it left me with the problem of not being able to easily test those settings. Say 9/10 tests required the service to be active, but 1 test wanted to test "ServiceIsActive = false;", now I'm in trouble.
Now, however, I am able to inject the configuration from the test :
[Given(#"Config\.IsServiceActive returns false")]
public void GivenConfig_IsServiceActiveReturnsFalse()
{
var settings = new DispatchSettings
{
ServiceIsActive = false,
DispatchProcessBatchSize = 100,
UpdatedBy = "Unit Test"
};
DispatchConfiguration.ConfigureStructureMap(ObjectFactory.Container, settings);
}
And then in the real world I am able to get the settings from app.config :
public void Start(String[] args)
{
var dispatchConfig = this.GetDispatchConfiguration();
DispatchConfiguration.ConfigureStructureMap(ObjectFactory.Container, dispatchConfig);
...
}
private IDispatchConfiguration GetDispatchConfiguration()
{
var config = (DispatchSettings)ConfigurationManager.GetSection("DispatchSettings");
return config;
}
And then the actual config class looks like :
[XmlRoot(ElementName = "DispatchSettings", Namespace = "")]
public sealed class DispatchSettings : IDispatchConfiguration
{
public Int32 DispatchProcessBatchSize { get; set; }
public Boolean ServiceIsActive { get; set; }
...
}
For the sake of completeness the interface looks like so :
public interface IDispatchConfiguration
{
Int32 DispatchProcessBatchSize { get; }
Boolean ServiceIsActive { get; }
...
}
And finally, the config file looks like this :
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="DispatchSettings" type="MyNamespace.XmlConfigurator, MyNamespace.Core" />
</configSections>
<DispatchSettings type="MyNamespace.DispatchSettings, MyNamespace.Core">
<ServiceIsActive>True</ServiceIsActive>
<DispatchProcessBatchSize>100</DispatchProcessBatchSize>
</DispatchSettings>
Now, anyone with a keen eye will spot "MyNamespace.XmlConfigurator". I found this on one of my Google journeys, and the code allows you to deserialize an Xml config into a class of your desire (as shown in this example). So, to ensure you have the complete code to make this technique work, below is the code for the XmlConfigurator. I cannot remember where I came across it, but a big thanks to the person who wrote it!!
public sealed class XmlConfigurator : IConfigurationSectionHandler
{
public XmlConfigurator()
{
}
public object Create(object parent, object configContext, XmlNode section)
{
XPathNavigator navigator = null;
String typeName = null;
Type sectionType = null;
XmlSerializer xs = null;
XmlNodeReader reader = null;
try
{
Object settings = null;
if (section == null)
{
return settings;
}
navigator = section.CreateNavigator();
typeName = (string)navigator.Evaluate("string(#type)");
sectionType = Type.GetType(typeName);
xs = new XmlSerializer(sectionType);
reader = new XmlNodeReader(section);
settings = xs.Deserialize(reader);
return settings;
}
finally
{
xs = null;
}
}
}
And there you have it! I hope this allows anyone with a similiar issue to resolve it and is clear enough to follow!
I was exploring the installer functionality of Castle Windsor based on the answers from a related question. I want to use the Web.config to specify the name of the database and I would rather not explicitly set the database name in my code. I tried Krzysztof Koźmic's example and when I debut the project my break-point at container.Register gets hit, but the dependency is still not resolved:
public class RepositoriesInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(AllTypes.FromThisAssembly()
.Where(Component.IsInSameNamespaceAs<SqlUsersRepository>())
.WithService.DefaultInterface()
.Configure(c => c.LifeStyle.Transient
.DependsOn(new { databaseName = "MyDatabaseName" })));
}
}
Sanders suggests that we can use the Web.config to resolve dependencies (note that he's doing this to get the connection string, but my connection string is encrypted so I'm doing in in a slightly different way):
<castle>
<components>
<component id="SqlUsersRepository"
service="MyDevArmyModel.Entities.IUsersRepository, MyDevArmyModel"
type="MyDevArmyModel.Entities.SqlUsersRepository, MyDevArmyModel">
<parameters>
<databaseName>MyDatabaseName</databaseName>
</parameters>
</component>
</components>
</castle>
My SqlUsersRepository and IUsersRepository are in the same namespace, but they're part of a class library which gets referenced in the current project. SqlUsersRepository looks up the connection string from the Web.Config the database name:
public interface IUsersRepository
{
IQueryable<User> Users { get; }
// ...
// and some other things
// ...
}
public class SqlUsersRepository : IUsersRepository
{
private DataContext dataContext;
private Table<User> usersTable;
public IQueryable<User> Users { get { return usersTable; } }
public SqlUsersRepository(string databaseName)
{
HttpRequestWrapper request = new HttpRequestWrapper(System.Web.HttpContext.Current.Request);
Configuration config = WebConfigurationManager.OpenWebConfiguration(request.ApplicationPath);
dataContext = new DataContext(config.GetConnetionString(databaseName));
usersTable = dataContext.GetTable<User>();
}
// .... the rest of the repository goes here
}
Any help on this?
P.S.
I'm still getting an exception, even if I use the hard-coded database name (as seen in the RepositoriesInstaller):
Server Error in '/' Application. Can't
create component
'MyProjectName.Controllers.UserController'
as it has dependencies to be
satisfied.
MyProjectName.Controllers.UserController
is waiting for the following
dependencies:
Services:
- MyProjectName.Entities.IUsersRepository
which was not registered. Description:
An unhandled exception occurred during
the execution of the current web
request. Please review the stack trace
for more information about the error
and where it originated in the code.
Exception Details:
Castle.MicroKernel.Handlers.HandlerException:
Can't create component
'MyProjectName.Controllers.UserController'
as it has dependencies to be
satisfied.
MyProjectName.Controllers.UserController
is waiting for the following
dependencies:
Services:
- MyProjectName.Entities.IUsersRepository
which was not registered.
Update
I've posted an answer which addresses the exception problem, but I'm yet to figure out how to use the Web.config to store Castle Windsor specific sections.
You should be able to achieve this by reducing the XML to this:
<castle>
<components>
<component id="SqlUsersRepository">
<parameters>
<databaseName>MyDatabaseName</databaseName>
</parameters>
</component>
</components>
</castle>
and then make sure your registration registers the repository under the right key/id - e.g. like this:
container.Register(AllTypes(...).Configure(c => c.Named(c.Implementation.Name)))
where all keys will be set to the short name of each concrete type.
Please note that this naming scheme might not be appropriate for you, so you should probably adapt the c.Named(...) to whatever you deem right for your use case. Just make sure that the registration key for your repository matches that if the id attribute in the XML.
DependsOn the way you've done it = the parameter named "databaseName" has a component dependency with a key "MyDatabaseName".
You want to do a .Parameters(ForKey.Named("databasename").Value(ConfigurationManager.ConnectionStrings["MyDatabasename"].ConnectionString)).LifeStyle.Transient. ...
I figured out the dependency exception... the issue was that my repositories are in a different assembly, so I had to rig the installation a bit:
public class RepositoriesInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
foreach (AssemblyName name in Assembly.GetExecutingAssembly().GetReferencedAssemblies())
{
Assembly asm = Assembly.Load(name);
container.Register(AllTypes.FromAssemblyNamed(asm.FullName)
.Where(Component.IsInSameNamespaceAs<SqlUsersRepository>())
.WithService.DefaultInterface()
.Configure(c => c.LifeStyle.Transient
.DependsOn(new { databaseName = "MyDatabaseName" })));
}
container.Register(AllTypes.FromThisAssembly()
.Where(Component.IsInSameNamespaceAs<SqlUsersRepository>())
.WithService.DefaultInterface()
.Configure(c => c.LifeStyle.Transient
.DependsOn(new { databaseName = "MyDatabaseName" })));
}
}
Still trying to figure out how to get the database name from the castle section of the Web.config though.
I want to load a dictionary at startup in my console app from my app.config.
I know that I could use an xml library or linq to XML to load it to parse and traverse it. My question is there a BUILT IN way of doing it.
Isn't there some way to add an application configuration section into the app.config and then have it loaded automagically using ConfigurationManager class in the System.Configuration namespace?
Any example? BTW, I am in NET20.
EDIT
Sorry, I should have clarified. I want to load the dictionary WITHOUT using AppSettings. I know how to do that already. Of course, the downside of using AppSettings is that I have to change my code to add new values to my dictionary. That is why I am looking for a way to do it automatically.
You will need to add an <appSettings> section to your app.config file. It will look something like:
<appSettings>
<add key="foo" value="fooValue" />
<add key="bar" value="barValue" />
<add key="baz" value="bazValue" />
</appSettings>
From within your app, you can grab these values with System.Configuration.ConfigurationManager.AppSettings, which is a NameValueCollection, which is essentially a dictionary from string to string.
string myFoo = System.Configuration.ConfigurationManager.AppSettings["foo"];
You can use the appSettings section the way you describe, but that section easily gets polluted with a variety of needs, and so I usually avoid it. You can make custom sections to deal with this.
Imagine you have a class called "PluginSpec," you can write code like this:
[ConfigurationCollection(typeof(PluginSpec), AddItemName = "Plugin",
CollectionType = ConfigurationElementCollectionType.BasicMap)]
public class PluginCollection : ConfigurationElementCollection
{
//This collection is potentially modified at run-time, so
//this override prevents a "configuration is read only" exception.
public override bool IsReadOnly()
{
return false;
}
protected override ConfigurationElement CreateNewElement()
{
return new PluginSpec();
}
protected override object GetElementKey(ConfigurationElement element)
{
PluginSpec retVal = element as PluginSpec;
return retVal.Name;
}
public PluginSpec this[string name]
{
get { return base.BaseGet(name) as PluginSpec; }
}
public void Add(PluginSpec plugin){
this.BaseAdd(plugin);
}
}
The above code can be used from a member of another config class, like this:
[ConfigurationProperty("", IsDefaultCollection = true)]
public PluginCollection Plugins
{
get
{
PluginCollection subList = base[""] as PluginCollection;
return subList;
}
}
The above would be a member in a class that derives from ConfigurationElement or ConfigurationSection.