How should I create the subsonic 3.0 DB context class? - subsonic

I'm new to SubSonic (of all flavours), but thought I might as well start with 3.0, because I'd like to use Linq, and I get the impression 3.0 is not that far away from release.
I tried the alpha download .zip, but that seems pretty old and didn't singularize table class names, so I'm now running from the latest trunk SVN version (rev62).
I've run the 'simple' templates, from SubSonic.Templates\Simple against my database and everything seems ok, but the DB context class which the templates create starts like this:
public partial class DB : IQuerySurface
{
static DB _db;
public DB() {
_db = new DB();
}
public static DB CreateDB()
{
if (_db == null)
{
_db = new DB();
_db.Init();
}
return _db;
}
... etc
Unsurprisingly, when I call DB.CreateDB, the ctor recurses endlessly and crashes everything with a stack overflow.
I don't really understand the ctor at all - it doesn't look like it should be there, but both the 'simple' and the 'advanced' templates create something similar, and there's a humongous test suite which I imagine is verifying this somehow.
Clearly I have the wrong end of the stick here - what blindingly obvious point have I missed?
Update: The simple and advanced templates aren't similar, and the advanced ones don't have this problem. Thanks for the help.
Another Update: It looks like this is fixed in the simple templates in SVN r66

Don't know if you have the latest bits from SVN with a bug, but my version from a few days ago appears to be working fine. Here is what my DB class starts off with:
public partial class DB : IQuerySurface
{
BatchQuery _batch = null;
public IDataProvider DataProvider;
public DbQueryProvider provider;
private IDatabaseSchema _schema;
public IDatabaseSchema Schema
{
get
{
return _schema;
}
}
public DB()
{
DataProvider = ProviderFactory.GetProvider("Northwind");
Init();
}
public DB(string instanceName, string connectStr)
{
SubSonic.DataProviders.ConnectionStringProvider.Instance.AddLocalConnectionString(
instanceName, connectStr, "System.Data.SqlClient");
DataProvider = ProviderFactory.GetProvider(instanceName);
Init();
}
... etc...
I used the advanced version of the templates.

I prefer the t4 templates, here is the ctor provided there:
public DB()
{
DataProvider = ProviderFactory.GetProvider("Northwind");
Init();
}
there is also an overload that accepts a connection string. This is working quite well for me, I'm using the linq support and it is full of awesome.

Related

How can I run code in JUnit before Spring starts?

How can I run code in my #RunWith(SpringRunner.class) #SpringBootTest(classes = {...}) JUnit test before Spring starts?
This question has been asked several times (e.g. 1, 2) but was always "solved" by some configuration recommendation or other, never with a universal answer. Kindly don't question what I am about to do in that code but simply suggest a clean way to do it.
Tried so far and failed:
Extend SpringJUnit4ClassRunner to get a class whose constructor can run custom code before initializing Spring. Failed because super(testClass) must be called first thing and already does a whole lot of things that get in the way.
Extend Runner to get a class that delegates to SpringRunner instead of inheriting it. This class could run custom code in its constructor before actually instantiating the SpringRunner. However, this setup fails with obscure error messages like java.lang.NoClassDefFoundError: javax/servlet/SessionCookieConfig. "Obscure" because my test has no web config and thus shouldn't meddle with sessions and cookies.
Adding an ApplicationContextInitializer that is triggered before Spring loads its context. These things are easy to add to the actual #SpringApplication, but hard to add in Junit. They are also quite late in the process, and a lot of Spring has already started.
One way to do it is to leave out SpringRunner and use the equivalent combination of SpringClassRule and SpringMethodRule instead. Then you can wrap the SpringClassRule and do your stuff before it kicks in:
public class SomeSpringTest {
#ClassRule
public static final TestRule TestRule = new TestRule() {
private final SpringClassRule springClassRule =
new SpringClassRule();
#Override
public Statement apply(Statement statement, Description description) {
System.out.println("Before everything Spring does");
return springClassRule.apply(statement, description);
}
};
#Rule
public final SpringMethodRule springMethodRule = new SpringMethodRule();
#Test
public void test() {
// ...
}
}
(Tested with 5.1.4.RELEASE Spring verison)
I don't think you can get more "before" than that. As for other options you could also check out #BootstrapWith and #TestExecutionListeners annotations.
Complementing jannis' comment on the question, the option to create an alternative JUnit runner and let it delegate to the SpringRunner does work:
public class AlternativeSpringRunner extends Runner {
private SpringRunner springRunner;
public AlternativeSpringRunner(Class testClass) {
doSomethingBeforeSpringStarts();
springRunner = new SpringRunner(testClass);
}
private doSomethingBeforeSpringStarts() {
// whatever
}
public Description getDescription() {
return springRunner.getDescription();
}
public void run(RunNotifier notifier) {
springRunner.run(notifier);
}
}
Being based on spring-test 4.3.9.RELEASE, I had to override spring-core and spring-tx, plus javax.servlet's servlet-api with higher versions to make this work.

C# 4, COM interop and UPnP: A trying triumvirate

I'm trying to write a bit of code (just for home use) that uses UPnP for NAT traversal, using C# 4 and Microsoft's COM-based NAT traversal API (Hnetcfg.dll).
Unfortunately (or perhaps fortunately) the last time I had to do COM interop in .NET was sometime around the last ice age, and I seem to be fundamentally confused about C#'s use of dynamic types for interop and how to write a callback (so that the COM server calls my managed code).
Here's an exciting few lines of code:
// Referencing COM NATUPNPLib ("NATUPnP 1.0 Type Library")
using System;
using NATUPNPLib;
class NATUPnPExample
{
public delegate void NewNumberOfEntriesDelegate(int lNewNumberOfEntries);
public static void NewNumberOfEntries(int lNewNumberOfEntries)
{
Console.WriteLine("New number of entries: {0}", lNewNumberOfEntries);
}
public static void Main(string[] args)
{
UPnPNAT nat = new UPnPNAT();
NewNumberOfEntriesDelegate numberOfEntriesCallback = NewNumberOfEntries;
nat.NATEventManager.NumberOfEntriesCallback = numberOfEntriesCallback;
nat.StaticPortMappingCollection.Add(4555, "TCP", 4555, "192.168.0.1", true, "UPnPNAT Test");
// Presumably my NewNumberOfEntries() method should be called by the COM component about now
nat.StaticPortMappingCollection.Remove(4555, "TCP");
}
}
In the above code, the Add and Remove calls work absolutely fine. Terrific.
The trouble is, I would also like to know when the number of port mapping entries have changed, and to do so I need to register a callback interface (INATEventManager::put_NumberOfEntriesCallback), which must support the INATNumberOfEntriesCallback or IDispatch interfaces. VS2012's object browser describes INATEventManager::put_NumberOfEntriesCallback thusly:
dynamic NumberOfEntriesCallback { set; }
Right, so I was under the impression that in C# 4 I shouldn't have to decorate anything with fancy attributes and that I can register my callback simply by jamming a delegate into INATEventManager::put_NumberOfEntriesCallback in a vulgar manner and leaving .NET to worry about IDispatch and clear up the mess; but it appears that I'm terribly wrong.
So, er... What should I do to ensure my NewNumberOfEntries method is called?
I'm also slightly concerned that I can write nat.NATEventManager.NumberOfEntriesCallback = 1; or nat.NATEventManager.NumberOfEntriesCallback = "Sausages"; without an exception being thrown.
It seems that I was able to make it work. Two options - with a custom interface "INATNumberOfEntriesCallback" (which does not seem to be declared in the type library btw, you need to declare it yourself) and using plain dispatch with DispId(0). The conversion to the IDispatch/IUnknown is preformed by the framework automatically. So:
Option 1.
Declare the INATNumberOfEntriesCallback and make a callback class which implements that interface (the tricky part is Guid - it comes from the "Natupnp.h" file, and does not seem to appear to be in the type library).
// declare INATNumberOfEntriesCallback interface
[ComVisible(true)]
[Guid("C83A0A74-91EE-41B6-B67A-67E0F00BBD78")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface INATNumberOfEntriesCallback
{
void NewNumberOfEntries(int val);
};
// implement callback object
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.None)]
public class CallbackNewNumberOfEntries : INATNumberOfEntriesCallback
{
public void NewNumberOfEntries(int val)
{
Console.WriteLine("Number of entries changed: {0}", val);
}
}
class NATUPnPExample
{
public static void Main(string[] args)
{
var nat = new UPnPNAT();
nat.NATEventManager.NumberOfEntriesCallback = new CallbackNewNumberOfEntries();
nat.StaticPortMappingCollection.Add(4555, "TCP", 4555, "192.168.0.1", true, "UPnPNAT Test");
// Presumably my NewNumberOfEntries() method should be called by the COM component about now
nat.StaticPortMappingCollection.Remove(4555, "TCP");
}
}
Option 2.
Use plain dispatch. The documentation says that you can use dispid(0) and it should be called, with 4 (!) parameters (see the remarks section in docs). So basically the following construction seems to work in "dispatch" way:
[ComVisible(true)]
[ClassInterface(ClassInterfaceType.AutoDispatch)]
public class CallbackDisp
{
[DispId(0)]
public void OnChange(string updateType, object obj, object name, object val)
{
Console.WriteLine("{0}: {1} = {2}", updateType, name, val);
}
}
class NATUPnPExample
{
public static void Main(string[] args)
{
var nat = new UPnPNAT();
nat.NATEventManager.NumberOfEntriesCallback = new CallbackDisp();
nat.StaticPortMappingCollection.Add(4555, "TCP", 4555, "192.168.0.1", true, "UPnPNAT Test");
// Presumably my NewNumberOfEntries() method should be called by the COM component about now
nat.StaticPortMappingCollection.Remove(4555, "TCP");
}
}
I had the same problem you had, and since there isn't much help on the topic your posting helped tremendously! It wouldn't let me comment on your answer because I don't have enough points or whatever but your answer is the best, but doesn't quite work how I thought it would.
nat.NATEventManager.ExternalIPAddressCallback = new CallbackDisp();
Works, using the same dispatch, and will tell you when the external IP changes. HOWEVER,
nat.NATEventManager.NumberOfEntriesCallback = new CallbackDisp();
only reports UPnP map changes from these conditions: A.) It was added/removed by the NATUPnP instance.. In this case:
nat.StaticPortMappingCollection.Add();
OR B.) it was already mapped when the instance was created:
var nat = new UPnPNAT();
As an example, if Utorrent was running when you started your program and you you had something to block the program from exiting(Console.WriteLine();) for example.. When you exit Utorrent the callback would fire, and notify you of the map changes. Which is exactly what I wanted in the first place. However, if you re-open Utorrent, or any other app that uses UPnP it will NOT fire the callback, and will not notify you of the change.
Needless to say it has been very frustrating. If you figure it out please share! I know I can easily implement the functionality by polling the StaticPortMappingCollection at a given interval, but it seems a little 'hacky' to me.

Using IQueryable<TEntity> instead DbSet<TEntity> problem

i stumbled to the next problem... I have database context:
// For support unit testing...
public interface IDbContext : IDisposable
{
IQueryable<Hardware> Hardwares { get; }
IQueryable<ProviderHardware> ProviderHardwares { get; }
}
// Real DbContext (EF 4.0, Code First)
public class PrimaryDbContext : DbContext, IDbContext
{
public DbSet<Hardware> Hardwares { get; set; }
public DbSet<ProviderHardware> ProviderHardwares { get; set; }
IQueryable<Hardware> IDbContext.Hardwares
{ get { return Hardwares; } }
IQueryable<ProviderHardware> IDbContext.ProviderHardwares
{ get { return ProviderHardwares; } }
...
}
And i try get all hardwares, which doesnt exists in ProviderHardwares table:
var hardwaresRemoved = db.Hardwares.Where(i => (i.IsAvailable == true) &&
(db.ProviderHardwares.Count(j => j.Article == i.Article) == 0)).ToList();
If i use PrimaryDbContext strictly such as "PrimaryDbContext db = new PrimaryDbContext();" all work fine. But if i use it implicitly "IDbContext db = new PrimaryDbContext();" that i get an exception:
Unable to create a constant value of type
'ConfiguratorMvcApplication.DomainModels.ProviderHardware'. Only
primitive types ('such as Int32, String, and Guid') are supported in
this context.
Summarize, i can't replace a DbSet on an IQueryable. And how i can use unit testing in this case? I hope someone have resolved this problem yet...
Thank in advance very much!
I ended up having two properties for each DbSet: one of type IQueryable, and one of type DbSet. The IQueryable property is defined in the interface, and it relays the calls to the concrete implementation (property of type DbSet), as follows:
// Exists in the interface
public IQueryable<AccountContact> AccountContacts
{
get
{
return DbAccountContacts;
}
set
{
DbAccountContacts = (DbSet<AccountContact>)value;
}
}
// Exists only in the implementation
public DbSet<AccountContact> DbAccountContacts { get; set; }
Having this setup, I was able to get mocking to work correctly and could unit test the code.
This is definitely too late for the OP, but maybe this helps someone who is struggling with the same question, as I did.
I suggest you better keep DbSets and do INTEGRATION TESTING including the database.
Because, although passing a unit test with a mock of a DB could be somewhat usefull, you are going to be better off testing with real database (but it's not unit testing).
On the ClassInitialize erase the database and/or create the initial data for testing.
If you create an App.config file with a connection string you can have a separate test database, and if you are using EF Code First, you get it for free.
Best regards.

How to force the order of Installer Execution

I have been building a new .NET solu­tion with Cas­tle per­form­ing my DI.
Its now at the stage where i would like to con­trol the order in which my installers run. I have built indi­vid­ual classes which implement IWind­sorIn­staller to han­dle my core types — eg IRepos­i­tory, IMap­per and ISer­vice to name a few.
I see that its suggested i implement my own Installer­Fac­tory (guessing i just override Select) in this class.
Then use this new factory in my call to:
FromAssembly.InDirectory(new AssemblyFilter("bin loca­tion"));
My ques­tion — when over­rid­ing the save method — what is the best way to force the order of my installers.
I know its already solved but I couldn't find any example on how to actually implement the InstallerFactory so here's a solution if anyone is googling for it.
How to use:
[InstallerPriority(0)]
public class ImportantInstallerToRunFirst : IWindsorInstaller
{
public void Install(IWindsorContainer container, Castle.MicroKernel.SubSystems.Configuration.IConfigurationStore store)
{
// do registrations
}
}
Just add the InstallerPriority attribute with a priority to your "install-order-sensitive" classes. Installers will be sorted by ascending. Installers without priority will default to 100.
How to implement:
public class WindsorBootstrap : InstallerFactory
{
public override IEnumerable<Type> Select(IEnumerable<Type> installerTypes)
{
var retval = installerTypes.OrderBy(x => this.GetPriority(x));
return retval;
}
private int GetPriority(Type type)
{
var attribute = type.GetCustomAttributes(typeof(InstallerPriorityAttribute), false).FirstOrDefault() as InstallerPriorityAttribute;
return attribute != null ? attribute.Priority : InstallerPriorityAttribute.DefaultPriority;
}
}
[AttributeUsage(AttributeTargets.Class)]
public sealed class InstallerPriorityAttribute : Attribute
{
public const int DefaultPriority = 100;
public int Priority { get; private set; }
public InstallerPriorityAttribute(int priority)
{
this.Priority = priority;
}
}
When starting application, global.asax etc:
container.Install(FromAssembly.This(new WindsorBootstrap()));
You can call your installers in the order they need to be instantiated in Global.asax.cs or e.g. in a Bootstrapper class, which is called from Global.asax.cs.
IWindsorContainer container = new WindsorContainer()
.Install(
new LoggerInstaller() // No dependencies
, new PersistenceInstaller() // --""--
, new RepositoriesInstaller() // Depends on Persistence
, new ServicesInstaller() // Depends on Repositories
, new ControllersInstaller() // Depends on Services
);
They are instantiated in this order, and you can add a breakpoint after and check the container for "Potentially misconfigured components".
If there are any, check their Status->details, if not, it's the correct order.
This solution is quick and easy, the documentation mentions using a InstallerFactory Class for tighter control over your installers so if you have a ton of installers the other solution may fit better. (Using code as convention should not require tons of installers?)
http://docs.castleproject.org/Windsor.Installers.ashx#codeInstallerFactorycode_class_4
In the end i had to use InstallerFactory and implement the ordering rules as suggested previously by returning the IEnumerable<Type> with my specific order

Subsonic 3, how to CRUD using LinqTemplates?

I am new to Subsonic, and it seems that I cant find out a natural way to do CRUD operations using the LINQ template classes. I guess in ActiveRecord, you could:
Product p = new Product();
p.ProductCode = "xxx";
p.Add();
Using the LINQTemplate generated classes however, how can I do the same thing? I can only use something like this below to insert a product object:
db.Insert.Into<UnleashedSaaS.PRODUCT>(prod => prod.Code, prod => prod.Description).Values("Product1", "Product1 Desc").Execute();
Who could kindly give me some hints? I'd really appreciate it.
All the CRUD happens in SubSonicRepository, which you can derive from. For example, I would have a class like this:
public class ProductRepository : SubSonicRepository<Product> {
public ProductRepository() : base(new NorthwindDB()) { }
// need this here because base doesn't expose the DB class that I know of
protected NorthwindDB _db;
protected NorthwindDB DB {
get {
if (_db == null) _db = new NorthwindDB();
return _db;
}
}
public void Save(Product product) {
if (product.ProductId == 0) {
Add(product); // Add is part of SubSonicRepository
} else {
Update(product);
}
}
public void Delete(Product product) { ... }
public List<Product> ListAll() {
var products = from p in DB.Products
select p;
return products.ToList();
}
public Product GetById(int id) {
return DB.GetByKey(id);
}
}
And so on. It's nice because you can consolidate all your data access methods in one place. If you have Sprocs, they're generated as methods on DB as well.
When I get time I'm going to work on adding a Save method to SubSonicRepository directly so you don't have to do the check yourself to see which method (Add or Update) to call.
I have modified the Classes.tt file to include:
public partial class <#=tbl.ClassName#>Repository : SubSonicRepository<<#=tbl.ClassName#>>
{
public <#=tbl.ClassName#>Repository() : base(new <#=DatabaseName#>DB()) { }
}
Insert that bunch of lines between
<# foreach(Table tbl in tables){#>
and
/// <summary>
right at the top, near the namespace declaration, in my file it can be inserted in line 18.
The last thing to do is to add another "using" statement, in line 10, the next line after System.Linq statement. Now it should look like:
using System.Linq;
using SubSonic.Repository;
That will generate a repository to give you access to basic functionality, but can be modified in another partial class.
Hope that helps.

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