I am developing an e-commerce website that utilises db4o as the backend. All was well until last week when I came across a problem that I have been unable to solve. The code below is quite straight forward. I open a database file, save an object and then try to retrieve it. However I get nothing back. The "users" variable has a count of zero.
public class Program
{
private static string _connectionString = string.Format(#"c:\aaarrrr.db4o");
static void Main(string[] args)
{
TestUser container = new TestUser() { id = 1, Name = "Mohammad", Surname = "Rafiq" };
Db4oFactory.Configure().Diagnostic().AddListener(new DiagnosticToConsole());
using (var dbc = Db4oFactory.OpenFile(_connectionString))
{
dbc.Store(container);
}
IList<TestUser> users = null;
using (var dbc = Db4oFactory.OpenFile(_connectionString))
{
users = dbc.Query<TestUser>(x => x.id == 1).ToList();
}
if (users.Count > 0)
{
Console.WriteLine("{0} {1} with id of {2}", users.First().Name, users.First().Surname, users.First().id);
}
else
{
Console.WriteLine("\nNo data returned.");
}
Console.ReadLine();
}
}
public class TestUser
{
[Indexed]
private int _id = 0;
private string _name = string.Empty;
private string _surname = string.Empty;
public int id { get { return _id; } set { _id = value; } }
public string Name { get { return _name; } set { _name = value; } }
public string Surname { get { return _surname; } set { _surname = value; } }
}
I have attached db4o diagnostic listener and I see nothing in the console output. Everything seems fine. I know I am writing to the file because I can see the file size increase and the timestamp is also updated. I have checked all the project settings and they are all set to default. I am using .net 4, visual studio 2010 beta and windows 7. I have done some reading regarding reflection permission but I cant see how this applies here. Any help or ideas would be knidly appreciated.
After calling store(), you need to commit() before leaving the using{} statement. You closed your database before committing your changes.
Related
Since I have a global exception handler that reports uncaught errors via e-mail, next step is to add some context to it by having some 10-20 last lines of log that are collected.
So I am using MemoryTarget like so:
MemoryTarget _logTarget;
_logTarget = new MemoryTarget();
_logTarget.Layout = "${longdate}|${level:uppercase=true}|${logger}|${message}${exception}";
LoggingRule loggingRule = new LoggingRule("*", LogLevel.Debug, _logTarget);
LogManager.Configuration.AddTarget("exceptionMemory", _logTarget);
LogManager.Configuration.LoggingRules.Add(loggingRule);
LogManager.Configuration.Reload();
Apps containing this should run forever, and if I leave logs in memory, unchecked, I'll have neatly designed memory leak.
How to address this? How to truncate MemoryTarget.Logs to have at most say 100 lines?
Your best bet is probably to write your own MemoryTarget... Something like this (untested) should work.
namespace NLog.Targets
{
using System.Collections.Generic;
[Target("LimitedMemory")]
public sealed class LimitedMemoryTarget : TargetWithLayout
{
private Queue<string> logs = new Queue<string>();
public LimitedMemoryTarget()
{
this.Logs = new List<string>();
}
public IEnumerable<string> Logs
{
get { return logs; }
private set { logs = value; }
}
[DefaultValue(100)]
public int Limit { get; set; }
protected override void Write(LogEventInfo logEvent)
{
string msg = this.Layout.Render(logEvent);
logs.Enqueue(msg);
if (logs.Count > Limit)
{
logs.Dequeue();
}
}
}
}
This example is based on the NLog MemoryTarget, the source code for which you can find here:
https://github.com/NLog/NLog
NLog docs are here:
http://nlog-project.org/documentation/v2.0.1/
I didn't see anything like you are asking about in either location.
I'm creating my own IntelliSense Presenter, since Visual Studio2012 support change theme, so I want my background color of the presenter can be auto-changed when the theme been changed. Is there a way to track the theme changes event, or get the current color theme of the Visual Studio?
Yes, this is possible. I had to solve a similiar issue with one of my extensions...
The current theme is stored in the Windows Registry; so I implemented the following utility class.
public enum VsTheme
{
Unknown = 0,
Light,
Dark,
Blue
}
public class ThemeUtil
{
private static readonly IDictionary<string, VsTheme> Themes = new Dictionary<string, VsTheme>()
{
{ "de3dbbcd-f642-433c-8353-8f1df4370aba", VsTheme.Light },
{ "1ded0138-47ce-435e-84ef-9ec1f439b749", VsTheme.Dark },
{ "a4d6a176-b948-4b29-8c66-53c97a1ed7d0", VsTheme.Blue }
};
public static VsTheme GetCurrentTheme()
{
string themeId = GetThemeId();
if (string.IsNullOrWhiteSpace(themeId) == false)
{
VsTheme theme;
if (Themes.TryGetValue(themeId, out theme))
{
return theme;
}
}
return VsTheme.Unknown;
}
public static string GetThemeId()
{
const string CategoryName = "General";
const string ThemePropertyName = "CurrentTheme";
string keyName = string.Format(#"Software\Microsoft\VisualStudio\11.0\{0}", CategoryName);
using (RegistryKey key = Registry.CurrentUser.OpenSubKey(keyName))
{
if (key != null)
{
return (string)key.GetValue(ThemePropertyName, string.Empty);
}
}
return null;
}
}
Okay; this just helps to figur out the current settings... listening for the theme changed notification is a bit trickier. After your package is loaded, you must obtain an IVsShell instance via the DTE; once you have this object you can utilize the AdviceBroadcastMessages method to subscribe for event notifications. You have to provide an object whose type implements the IVsBroadcastMessageEvents interface...
I don´t want to post the whole implementation, but the following lines might illustrate the key scenario...
class VsBroadcastMessageEvents : IVsBroadcastMessageEvent
{
int IVsBroadcastMessageEvent.OnBroadcastMessage(uint msg, IntPtr wParam, IntPtr lParam)
{
const uint WM_SYSCOLORCHANGE = 0x15;
if (msg == WM_SYSCOLORCHANGE)
{
// obtain current theme from the Registry and update any UI...
}
}
}
Consider implementing IDisposable on that type as well, in order to be able to unsubscribe from the event source, when the package gets unloaded.
This is how I subscribe for event notifications...
class ShellService
{
private readonly IVsShell shell;
private bool advised;
public ShellService(IVsShell shellInstance)
{
this.shell = shellInstance;
}
public void AdviseBroadcastMessages(IVsBroadcastMessageEvents broadcastMessageEvents, out uint cookie)
{
cookie = 0;
try
{
int r = this.shell.AdviseBroadcastMessages(broadcastMessageEvents, out cookie);
this.advised = (r == VSConstants.S_OK);
}
catch (COMException) { }
catch (InvalidComObjectException) { }
}
public void UnadviseBroadcastMessages(uint cookie)
{
...
}
}
Keep the value of the cookie parameter; you´ll need it to successfully unsubscribe.
Hope that helps (-:
Just wanted to put an update just in case anyone else comes along.. #Matze and #Frank are totally right.. However in VS 2015.. they added a easy way to detect the theme change. So you need to include PlatformUI an dyou get a super easy event
using Microsoft.VisualStudio.PlatformUI;
....
//Then you get an event
VSColorTheme.ThemeChanged += VSColorTheme_ThemeChanged;
You should make sure your control is disposable so you can unsubscribe from the event...
BONUS!
It also give you easy access to the colors.. even if the user has changed them from the default .. so you can do stuff like this in when set your colors
var defaultBackground = VSColorTheme.GetThemedColor(EnvironmentColors.ToolWindowBackgroundColorKey);
var defaultForeground = VSColorTheme.GetThemedColor(EnvironmentColors.ToolWindowTextColorKey);
For VS 2015 this has changed, the solution #Matze has still works but you need to update the GetThemeId() function to check for the version and if it's 14.0 (VS2015) look in a different place in the registry. The way the value is stored has changed also, it's still a string but now contains other values seperated by a '*'. The theme guid is the last value in the list.
if (version == "14.0")
{
string keyName = string.Format(#"Software\Microsoft\VisualStudio\{0}\ApplicationPrivateSettings\Microsoft\VisualStudio", version);
using (RegistryKey key = Registry.CurrentUser.OpenSubKey(keyName))
{
if (key != null)
{
var keyText = (string)key.GetValue("ColorTheme", string.Empty);
if (!string.IsNullOrEmpty(keyText))
{
var keyTextValues = keyText.Split('*');
if (keyTextValues.Length > 2)
{
return keyTextValues[2];
}
}
}
}
return null;
}
I am writing a custom module that retrieves and pushes data directly from the Orchard DB using an injected IRepository.
This works fine until i need to update a content part. I add an update in my migrations class and the update runs through (DB schema updated with default values), however I can't update any of the new values through IRepository. I have to drop down into the NHibernate.ISession to flush the changes through.
This all works fine on a newly created recipe, it's only when i alter a part. Here are the key code snippets:
public class TranslationsPartRecord : ContentPartRecord
{
internal const string DefaultProductName = "Product";
public TranslationsPartRecord()
{
ProductName = DefaultProductName;
}
public virtual string ProductName { get; set; }
}
public class TranslationsPart : ContentPart<TranslationsPartRecord>
{
public string ProductName
{
get { return Record.ProductName; }
set { Record.ProductName = value; }
}
}
public class TranslationsHandler : ContentHandler
{
public TranslationsHandler(IRepository<TranslationsPartRecord> repository)
{
Filters.Add(StorageFilter.For(repository));
}
}
public class Migrations : DataMigrationImpl
{
public int Create()
{
SchemaBuilder.CreateTable("TranslationsPartRecord", table => table
.Column<int>("Id", column => column.PrimaryKey().Identity())
.Column("ProductName", DbType.String, column => column.NotNull().WithDefault(TranslationsPartRecord.DefaultProductName))
);
return 1;
}
public int UpdateFrom1()
{
SchemaBuilder.AlterTable("TranslationsPartRecord", table => table.AddColumn("ProductDescription", DbType.String, column => column.NotNull().WithDefault(TranslationsPartRecord.DefaultProductDescription)));
return 2;
}
}
When i add the second property "ProductDescription" in this example, after the update is run the columns appear in the DB but i cannot update them until i recreate the Orchard recipe (blat App_Data and start again).
here's how I am trying to update:
// ctor
public AdminController(IRepository<TranslationsPartRecord> translationsRepository)
{
_translationsRepository = translationsRepository;
}
[HttpPost]
public ActionResult Translations(TranslationsViewModel translationsViewModel)
{
var translations = _translationsRepository.Table.SingleOrDefault();
translations.ProductName = translationsViewModel.ProductName;
translations.ProductDescription = translationsViewModel.ProductDescription;
_translationsRepository.Update(translations);
_translationsRepository.Flush();
}
and here's the NHibernate "fix":
var session = _sessionLocator.For(typeof(TranslationsPartRecord));
var translations = _translationsRepository.Table.SingleOrDefault();
// is translations.Id always 1?
var dbTranslations = session.Get<TranslationsPartRecord>(translations.Id);
dbTranslations.ProductName = translationsViewModel.ProductName;
dbTranslations.ProductDescription = translationsViewModel.ProductDescription;
session.Update(dbTranslations);
session.Flush();
which seems a bit kludgey...
Cheers.
ps i'm still running Orchard 1.3.9
pps after more testing, the NHibernate fix has stopped working now, so perhaps my initial findings were a red herring. It seems as though new properties on the content part are totally ignored by NHibernate when updating/retrieving - as though the object definition is cached somewhere...
If your mappings aren't being updated that is strange. You can try to force it by deleting the mappings.bin in the app_data folder, and restarting the application. Orchard should recreate the nhibernate mappings and save as mappings.bin.
I have ran into the same issue, and the only way around it that I can find is to delete mappings.bin (I don't need to disable and re-enable the module). In fact, this is the answer that I got from Bertrand when I asked why this was happening.
I have logged this as an issue at http://orchard.codeplex.com/workitem/19306. If you could vote this up, then we may get it looked at quicker.
This seems like a similar issue to what I am seeing... I am seeing that when you enable a module, it runs the NHibernate mappings BEFORE running the Migrations..
https://orchard.codeplex.com/workitem/19603
Josh
Update the hash value in the ComputingHash method in the PersistenceConfiguration Class,
updating the hash value may recreate the mappings.bin file.
public class PersistenceConfiguration : ISessionConfigurationEvents
{
public void Created(FluentConfiguration cfg, AutoPersistenceModel defaultModel)
{
DoModelMapping(cfg, defaultModel);
}
public void ComputingHash(Hash hash)
{
hash.AddString("Some_strings_to_update_hash");
}
private void DoModelMapping(FluentConfiguration cfg, AutoPersistenceModel defaultModel)
{
// mappings here....
}
public void Prepared(FluentConfiguration cfg) { }
public void Building(Configuration cfg) { }
public void Finished(Configuration cfg) { }
}
I'm trying to write a target for NLog to send messages out to connected clients using SignalR.
Here's what I have now. What I'm wondering is should I be using resolving the ConnectionManager like this -or- somehow obtain a reference to the hub (SignalrTargetHub) and call a SendMessage method on it?
Are there performance ramifications for either?
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
public SignalR.IConnectionManager ConnectionManager { get; set; }
public SignalrTarget()
{
ConnectionManager = AspNetHost.DependencyResolver.Resolve<IConnectionManager>();
}
protected override void Write(NLog.LogEventInfo logEvent)
{
dynamic clients = GetClients();
var logEventObject = new
{
Message = this.Layout.Render(logEvent),
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("yyyy-MM-dd HH:mm:ss.fff")
};
clients.onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return ConnectionManager.GetClients<SignalrTargetHub>();
}
}
I ended up with the basic the same basic structure that I started with. Just a few tweaks to get the information I needed.
Added exception details.
Html encoded the final message.
[Target("Signalr")]
public class SignalrTarget:TargetWithLayout
{
protected override void Write(NLog.LogEventInfo logEvent)
{
var sb = new System.Text.StringBuilder();
sb.Append(this.Layout.Render(logEvent));
if (logEvent.Exception != null)
sb.AppendLine().Append(logEvent.Exception.ToString());
var message = HttpUtility.HtmlEncode(sb.ToString());
var logEventObject = new
{
Message = message,
Logger = logEvent.LoggerName,
Level = logEvent.Level.Name,
TimeStamp = logEvent.TimeStamp.ToString("HH:mm:ss.fff")
};
GetClients().onLoggedEvent(logEventObject);
}
private dynamic GetClients()
{
return AspNetHost.DependencyResolver.Resolve<IConnectionManager>().GetClients<SignalrTargetHub>();
}
}
In my simple testing it's working well. Still remains to be seen if this adds any significant load when under stress.
I'm trying to get windows workflows working, and I've become a little stumped.
I've gotten a single workflow working, but now I am trying to do something a little more complex: start a workflow, where each activity itself contains a workflow. (Picture something like the main program starts the activities "Input, logic, and output", and then each of those have additional activities like "prompt user, get input, etc.")
I've had it working fine, with the example from here (http://msdn.microsoft.com/en-us/magazine/gg535667.aspx), when I am not passing any parameters from the main program to the activites. My question is, how exactly does the 'Variables' and 'metadata.SetVariablesCollection' work in the NativeActivity, and how to I get the parameters to the low level activities?
This is what I am currently trying:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
using System.Collections.ObjectModel;
using System.Activities.Statements;
namespace Project1
{
internal class MainProgram
{
internal static void Main(string[] args)
{
try
{
var act = new SimpleSequence();
act.Activities.Add((Activity)(new WriteSomeText()));
act.Activities.Add((Activity)(new WriteSomeText()));
act.Activities.Add((Activity)(new WriteSomeText()));
act.Variables.Add(new Variable<string> ("stringArg", "TEXT"));
WorkflowInvoker.Invoke(act);
}
catch (Exception ex)
{
System.Console.WriteLine("EXCEPTION: {0}", ex);
}
}
public class WriteSomeText : CodeActivity
{
[RequiredArgument]
public InArgument<string> stringArg { get; set; }
protected override void Execute(CodeActivityContext context)
{
string output = context.GetValue(stringArg);
System.Console.WriteLine(output);
}
}
public class SimpleSequence : NativeActivity
{
Collection<Activity> activities;
Collection<Variable> variables;
Variable<int> current = new Variable<int> { Default = 0 };
public Collection<Activity> Activities
{
get
{
if (this.activities == null)
this.activities = new Collection<Activity>();
return this.activities;
}
set
{
this.activities = value;
}
}
public Collection<Variable> Variables
{
get
{
if (this.variables == null)
this.variables = new Collection<Variable>();
return this.variables;
}
set
{
this.variables = value;
}
}
protected override void CacheMetadata(NativeActivityMetadata metadata)
{
metadata.SetChildrenCollection(this.activities);
metadata.SetVariablesCollection(this.variables);
metadata.AddImplementationVariable(this.current);
}
protected override void Execute(NativeActivityContext context)
{
if (this.Activities.Count > 0)
context.ScheduleActivity(this.Activities[0], onChildComplete);
}
void onChildComplete(NativeActivityContext context, ActivityInstance completed)
{
int currentExecutingActivity = this.current.Get(context);
int next = currentExecutingActivity + 1;
if (next < this.Activities.Count)
{
context.ScheduleActivity(this.Activities[next], this.onChildComplete);
this.current.Set(context, next);
}
}
}
}
}
This ends up throwing the following exception:
EXCEPTION: System.Activities.InvalidWorkflowException: The following errors were encountered while processing the workflow tree:
'WriteSomeText': Value for a required activity argument 'stringArg' was not supplied.
'WriteSomeText': Value for a required activity argument 'stringArg' was not supplied.
'WriteSomeText': Value for a required activity argument 'stringArg' was not supplied.
at System.Activities.Validation.ActivityValidationServices.ThrowIfViolationsExist(IList`1 validationErrors)
at System.Activities.Hosting.WorkflowInstance.ValidateWorkflow(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.Hosting.WorkflowInstance.RegisterExtensionManager(WorkflowInstanceExtensionManager extensionManager)
at System.Activities.WorkflowApplication.EnsureInitialized()
at System.Activities.WorkflowApplication.RunInstance(WorkflowApplication instance)
at System.Activities.WorkflowApplication.Invoke(Activity activity, IDictionary`2 inputs, WorkflowInstanceExtensionManager extensions, TimeSpan timeout)
at System.Activities.WorkflowInvoker.Invoke(Activity workflow, TimeSpan timeout, WorkflowInstanceExtensionManager extensions)
at System.Activities.WorkflowInvoker.Invoke(Activity workflow)
at Project1.MainProgram.Main(String[] args) in c:\users\user\documents\visual studio 2010\Projects\ModelingProject1\Project1\MainProgram.cs:line 25
I know, I only pass 1 parameter, but the exception still says that I am missing 3 parameters. I am missing something as to how to do this properly.
You're correctly declaring stringArg as an InArgument but you're not passing any value to it when calling it inside SimpleSequence.
You can pass something using the constructor, while constructing the all activity itself, like this:
public class WriteSomeText : CodeActivity
{
[RequiredArgument]
public InArgument<string> stringArg { get; set; }
public WriteSomeText(string stringArg)
{
this.stringArg = stringArg;
}
protected override void Execute(CodeActivityContext context
{
string output = context.GetValue(stringArg);
System.Console.WriteLine(output);
}
}
// Calling the activity like this:
internal static void Main(string[] args)
{
var act = new SimpleSequence()
{
Activities =
{
new WriteSomeText("hello"),
new WriteSomeText("world"),
new WriteSomeText("!")
}
};
WorkflowInvoker.Invoke(act);
Console.WriteLine("Press any key to exit");
Console.ReadKey();
}
Also notice that is a best practice to use the constructor to initialize collections:
public SimpleSequence()
{
activities = new Collection<Activity>();
variables = new Collection<Variable>();
}
This way is even more intuitive to initialize the activity:
var act = new SimpleSequence()
{
Activities =
{
new WriteSomeText("hello"),
new WriteSomeText("world"),
new WriteSomeText("!")
},
Variables =
{
new Variable<int>("myNewIntVar", 10),
// ....
}
};
EDIT:
There are a couple of other ways to approach the problem. This is your best friend while starting in the WF4 world.
Check WF\Basic\CustomActivities\Code-Bodied for a little push with this particular case.