i have just looked into hooking my application into nhibernate (fluent nhibernate) but i am having a few difficulties...
I have tried to follow what people have done and found this:
public class NHibernateSessionPerRequest : IHttpModule
{
private static readonly ISessionFactory _sessionFactory;
static NHibernateSessionPerRequest()
{
_sessionFactory = CreateSessionFactory();
}
public void Init(HttpApplication context)
{
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
public static ISession GetCurrentSession()
{
return _sessionFactory.GetCurrentSession();
}
public void Dispose() { }
private static void BeginRequest(object sender, EventArgs e)
{
ISession session = _sessionFactory.OpenSession();
session.BeginTransaction();
CurrentSessionContext.Bind(session);
}
private static void EndRequest(object sender, EventArgs e)
{
ISession session = CurrentSessionContext.Unbind(_sessionFactory);
if (session == null) return;
try
{
session.Transaction.Commit();
}
catch (Exception)
{
session.Transaction.Rollback();
}
finally
{
session.Close();
session.Dispose();
}
}
private static ISessionFactory CreateSessionFactory()
{
string connString = "AV8MediaUser";
FluentConfiguration configuration = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ShowSql().ConnectionString(
x => x.FromConnectionStringWithKey(connString)))
.ExposeConfiguration(
c => c.SetProperty("current_session_context_class", "web"))
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<Category>());
return configuration.BuildSessionFactory();
}
}
But when i run it through it seems to connect to the database correctly but it doesnt run a query:
return Session.CreateCriteria<Category>()
.List<Category>();
Am i doing something stupidly wrong?
CreateCriteria expects you to specify a model object name that you'd like to retrieve instances of. You seem to be missing your model object type name. Try something more like this:
List<YourModelObject> results = session.CreateCriteria<YourModelObject>()
.List<YourModelObject>();
To see what's actually being sent to the database consider using Ayende's NHProfiler - it will come in handy later when seeing what your more complex criteria queries or HQL queries actually result in...
Got it... i didnt realise that my mappings werent included in the project for some unknown reason... but included them again and it is all good!
Weird how it didnt throw an error though.
Related
I have a simple Solr query component as follows:
public class QueryPreprocessingComponent extends QueryComponent implements PluginInfoInitialized {
private static final Logger LOG = LoggerFactory.getLogger( QueryPreprocessingComponent.class );
private ExactMatchQueryProcessor exactMatchQueryProcessor;
public void init( PluginInfo info ) {
initializeProcessors(info);
}
private void initializeProcessors(PluginInfo info) {
List<PluginInfo> queryPreProcessors = info.getChildren("queryPreProcessors")
.get(0).getChildren("queryPreProcessor");
for (PluginInfo queryProcessor : queryPreProcessors) {
initializeProcessor(queryProcessor);
}
}
private void initializeProcessor(PluginInfo queryProcessor) {
QueryProcessorParam processorName = QueryProcessorParam.valueOf(queryProcessor.name);
switch(processorName) {
case ExactMatchQueryProcessor:
exactMatchQueryProcessor = new ExactMatchQueryProcessor(queryProcessor.initArgs);
LOG.info("ExactMatchQueryProcessor initialized...");
break;
default: throw new AssertionError();
}
}
#Override
public void prepare( ResponseBuilder rb ) throws IOException
{
if (exactMatchQueryProcessor != null) {
exactMatchQueryProcessor.modifyForExactMatch(rb);
}
}
#Override
public void process(ResponseBuilder rb) throws IOException
{
// do nothing - needed so we don't execute the query here.
return;
}
}
This works as expected functionally except when I use this in a distributed request, it has an issue with facets counts returned. It doubles the facet counts.
Note that I am not doing anything related to faceting in plugin. exactMatchQueryProcessor.modifyForExactMatch(rb); does a very minimal processing if the query is quoted otherwise it does nothing. Even if the incoming query is not quoted, facet count issue is there. Even if I comment everything inside prepare function, issue persists.
Note that this component is declared in as first-components in solrconfig.xml.
I resolved this issue by extending the class to SearchComponent instead of QueryComponent. It seems that SearchComponent sits at higher level of abstraction than QueryComponent and is useful when you want to work on a layer above shards.
We are using ASP.NET Zero and are running into issues with parallel processing from an AppService. We know requests must be transactional, but unfortunately we need to break out to slow running APIs for numerous calls, so we have to do parallel processing.
As expected, we are running into a DbContext contingency issue on the second database call we make:
System.InvalidOperationException: A second operation started on this context
before a previous operation completed. This is usually caused by different
threads using the same instance of DbContext, however instance members are
not guaranteed to be thread safe. This could also be caused by a nested query
being evaluated on the client, if this is the case rewrite the query avoiding
nested invocations.
We read that a new UOW is required, so we tried using both the method attribute and the explicit UowManager, but neither of the two worked.
We also tried creating instances of the referenced AppServices using the IocResolver, but we are still not able to get a unique DbContext per thread (please see below).
public List<InvoiceDto> CreateInvoices(List<InvoiceTemplateLineItemDto> templateLineItems)
{
List<InvoiceDto> invoices = new InvoiceDto[templateLineItems.Count].ToList();
ConcurrentQueue<Exception> exceptions = new ConcurrentQueue<Exception>();
Parallel.ForEach(templateLineItems, async (templateLineItem) =>
{
try
{
XAppService xAppService = _iocResolver.Resolve<XAppService>();
InvoiceDto invoice = await xAppService
.CreateInvoiceInvoiceItem();
invoices.Insert(templateLineItems.IndexOf(templateLineItem), invoice);
}
catch (Exception e)
{
exceptions.Enqueue(e);
}
});
if (exceptions.Count > 0) throw new AggregateException(exceptions);
return invoices;
}
How can we ensure that a new DbContext is availble per thread?
I was able to replicate and resolve the problem with a generic version of ABP. I'm still experiencing the problem in my original solution, which is far more complex. I'll have to do some more digging to determine why it is failing there.
For others that come across this problem, which is exactly the same issue as reference here, you can simply disable the UnitOfWork through an attribute as illustrated in the code below.
public class InvoiceAppService : ApplicationService
{
private readonly InvoiceItemAppService _invoiceItemAppService;
public InvoiceAppService(InvoiceItemAppService invoiceItemAppService)
{
_invoiceItemAppService = invoiceItemAppService;
}
// Just add this attribute
[UnitOfWork(IsDisabled = true)]
public InvoiceDto GetInvoice(List<int> invoiceItemIds)
{
_invoiceItemAppService.Initialize();
ConcurrentQueue<InvoiceItemDto> invoiceItems =
new ConcurrentQueue<InvoiceItemDto>();
ConcurrentQueue<Exception> exceptions = new ConcurrentQueue<Exception>();
Parallel.ForEach(invoiceItemIds, (invoiceItemId) =>
{
try
{
InvoiceItemDto invoiceItemDto =
_invoiceItemAppService.CreateAsync(invoiceItemId).Result;
invoiceItems.Enqueue(invoiceItemDto);
}
catch (Exception e)
{
exceptions.Enqueue(e);
}
});
if (exceptions.Count > 0) {
AggregateException ex = new AggregateException(exceptions);
Logger.Error("Unable to get invoice", ex);
throw ex;
}
return new InvoiceDto {
Date = DateTime.Now,
InvoiceItems = invoiceItems.ToArray()
};
}
}
public class InvoiceItemAppService : ApplicationService
{
private readonly IRepository<InvoiceItem> _invoiceItemRepository;
private readonly IRepository<Token> _tokenRepository;
private readonly IRepository<Credential> _credentialRepository;
private Token _token;
private Credential _credential;
public InvoiceItemAppService(IRepository<InvoiceItem> invoiceItemRepository,
IRepository<Token> tokenRepository,
IRepository<Credential> credentialRepository)
{
_invoiceItemRepository = invoiceItemRepository;
_tokenRepository = tokenRepository;
_credentialRepository = credentialRepository;
}
public void Initialize()
{
_token = _tokenRepository.FirstOrDefault(x => x.Id == 1);
_credential = _credentialRepository.FirstOrDefault(x => x.Id == 1);
}
// Create an invoice item using info from an external API and some db records
public async Task<InvoiceItemDto> CreateAsync(int id)
{
// Get db record
InvoiceItem invoiceItem = await _invoiceItemRepository.GetAsync(id);
// Get price
decimal price = await GetPriceAsync(invoiceItem.Description);
return new InvoiceItemDto {
Id = id,
Description = invoiceItem.Description,
Amount = price
};
}
private async Task<decimal> GetPriceAsync(string description)
{
// Simulate a slow API call to get price using description
// We use the token and credentials here in the real deal
await Task.Delay(5000);
return 100.00M;
}
}
I have two classes. First is using for store boolean value from ToggleSwitchButton by using IsolatedStorage.
Like this...
private void tglSwitch_Checked(object sender, RoutedEventArgs e)
{
System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] = true;
}
private void tglSwitch_Unchecked(object sender, RoutedEventArgs e)
{
System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] = false;
}
The second class will use the boolean value from the first class to do something.
Like this...
if(booleanValFromFirst){
//Do something
}
else{
//Do something
}
Thanks.
Is this, what you want?
if ((bool)System.IO.IsolatedStorage.IsolatedStorageSettings.ApplicationSettings["EnableLocation"] == true)
P.S. I would recommend for you to create a single class for all values, stored in Application Settings and work with it.
Like this:
public static class SettingsManager
{
private static IsolatedStorageSettings appSettings;
public static IsolatedStorageSettings AppSettings
{
get { return SettingsManager.appSettings; }
set { SettingsManager.appSettings = value; }
}
public static void LoadSettings()
{
// Constructor
if (appSettings == null)
appSettings = IsolatedStorageSettings.ApplicationSettings;
// Generate Keys if not created
if (!appSettings.Contains(Constants.SomeKey))
appSettings[Constants.SomeKey] = "Some Default value";
// generate other keys
}
}
Then you can work with that class instance
Initialize it at your startup class as SettingsManager.LoadSettings();
an then in any class just call for it:
if ((bool)SettingsManager.AppSettings[Constants.SomeBoolKey])
doSomething();
Could anyone help me in assessing why the code below doesn't work. I'm using the common extension method for implementing Include when using IObjectset. In our repositories we were seeing this not returning correctly so I've isolated the code in test app as below. I've also included the interface based Context if this may prove relevant and a screenshot of the relevant model section. This occurs for all Includes on IObjectSet properties not just the DPASelections one I've chosen for this example.
If I update the context to return ObjectSet (still using the POCO entities) rather than IObjectSet it all works fine. When using IObjectSet and the extension method and step through the code I see that the extension method is completing correctly with a call to the ObjectQuery we're casting to but the included entities are never returned on the graph. As said, this works perfectly when I don't interface out the Context and return ObjectSet properties hence calling Include directly on ObjectSet.
I'm not getting any errors on executing the query so this isn't the same as several other questions on SO which refer to compiled queries.
Has anyone else experienced problems with this extension method implementation or can anyone spot what I'm doing wrong here?
Any help very much appreciated.
static void Main(string[] args)
{
using (var context = new AssocEntities())
{
context.ContextOptions.LazyLoadingEnabled = false;
Candidate candidate = context.Candidates
.Include("DPASelections.DPAOption")
.SingleOrDefault(c => c.Number == "N100064");
//Count is 0 when using ext. method and IObjectSet through AssocContext but correct when using Include
//on ObjectSet through AssocContext
Console.WriteLine("DPASelection count = {0}",candidate.DPASelections.Count);
//This is always null when using IObjectSet and ext. method but populated
//when using Include on ObjectSet
var option = candidate.DPASelections.First().DPAOption;
Console.WriteLine("First DPAOption = {0} : {1}",option.Id,option.Text);
}
Console.ReadLine();
}
}
public static class Extensions
{
public static IQueryable<TSource> Include<TSource>(this IQueryable<TSource> source, string path)
{
var objectQuery = source as ObjectQuery<TSource>;
if (objectQuery != null)
{
objectQuery.Include(path);
}
return source;
}
}
//Subset of custom context implementing IObjectSet as returns.
//Works fine when I return ObjectSet rather than IObjectSet and use
//the Include method directly
public partial class AssocEntities : ObjectContext
{
public const string ConnectionString = "name=AssocEntities";
public const string ContainerName = "AssocEntities";
#region Constructors
public AssocEntities()
: base(ConnectionString, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
public AssocEntities(string connectionString)
: base(connectionString, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
public AssocEntities(EntityConnection connection)
: base(connection, ContainerName)
{
this.ContextOptions.LazyLoadingEnabled = true;
}
#endregion
#region IObjectSet Properties
public IObjectSet<Address> Addresses
{
get { return _addresses ?? (_addresses = CreateObjectSet<Address>("Addresses")); }
}
private IObjectSet<Address> _addresses;
public IObjectSet<Answer> Answers
{
get { return _answers ?? (_answers = CreateObjectSet<Answer>("Answers")); }
}
private IObjectSet<Answer> _answers;
public IObjectSet<Candidate> Candidates
{
get { return _candidates ?? (_candidates = CreateObjectSet<Candidate>("Candidates")); }
}
}
And the model...
I needed to replace objectQuery.Include(path); with objectQuery = objectQuery.Include(path);
In .Net framework 4.0 there is a build-in Extentionmethod for Include
just add the System.Data.Entity namespace.
It uses reflection - here is how it works:
private static T CommonInclude<T>(T source, string path)
{
MethodInfo method = source.GetType().GetMethod("Include", DbExtensions.StringIncludeTypes);
if (!(method != (MethodInfo) null) || !typeof (T).IsAssignableFrom(method.ReturnType))
return source;
return (T) method.Invoke((object) source, new object[1]
{
(object) path
});
}
This question relates to my other post.
Ok so after a bit more messing around I decided to do it this way. Which seems to work fine when I run it, although I'm getting the following error in NUnit: Could not load file or assembly 'Castle.Core, Version=1.0.3.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) So not sure what is happening there???
Just wanted to know what others thought about the design and if there are any obvious 'no no's' or improvements. I.e. Is the constructor of the base handler a good place to instantiate the windsor component or is there a better place to do this? As I said in the original post the idea behind doing things this way was to keep the components nicely decoupled and to make unit testing easy. I should also add I'm new to unit testing, mocking. Thanks!
public abstract class BaseHttpHandler : IHttpHandler
{
private HttpContext _httpContext;
private ILogger _logger;
private IDataRepository _dataRepository;
protected HttpRequest Request { get { return _httpContext.Request; } }
protected HttpResponse Response { get { return _httpContext.Response; } }
protected bool IsRequestFromUAD { get { return Request.UserAgent == null ? false : Request.UserAgent.Equals("UAD"); } }
protected ILogger Logger { get { return _logger; } }
protected IDataRepository DataRepository { get { return _dataRepository; } }
public virtual bool IsReusable { get { return false; } }
public BaseHttpHandler()
{
var container = new WindsorContainer(new XmlInterpreter(new ConfigResource("castle")));
_logger = container.Resolve<ILogger>();
_dataRepository = container.Resolve<IDataRepository>();
}
public void ProcessRequest(HttpContext context)
{
_httpContext = context;
ProcessRequest(new HttpContextWrapper(context));
}
public abstract void ProcessRequest(HttpContextBase context);
}
public class UADRecordHttpHandler : BaseHttpHandler
{
public override void ProcessRequest(HttpContextBase context)
{
if (IsRequestFromUAD)
{
using (var reader = new StreamReader(context.Request.InputStream))
{
string data = reader.ReadToEnd();
if (Logger != null)
Logger.Log(data);
if(DataRepository != null)
DataRepository.Write(data);
context.Response.Write(data);
}
}
else
ReturnResponse(HttpStatusCode.BadRequest);
}
}
That's a very bad thing to do, what you're doing here. You should have one instance of the container per application, while with this code you will have one per each request.
About the error in NUnit: make sure you don't have other versions of Castle assemblies in the GAC. If so, uninstall them.
About your BaseHttpHandler: the problem with this implementation is that you're creating a new container. Instead, use a single container per application, like Krzysztof said. Use a static service locator, e.g. CommonServiceLocator. (I never recommend this but it's one of the few places where it does make sense).