This DTO
[Route("/{Module}/{Name}")]
public class ViewEntityList {
public string Module { get; set; }
public string Name { get; set; }
}
causes my app to error on startup with
RestPath '/{Module}/{Name}' on Type 'ViewEntityList' is not Valid
I could change the route to begin with a literal (e.g. /Entity/{Module}/{Name}) but it's not what I want; besides, my URLs are starting to look excessively long and un-REST-like.
Is it possible to begin a route with a variable? If not, is there another way to map any route with two parts to a specific DTO?
I always do following:
//Configure User Defined REST Paths
Routes
.Add<DTO1>("/service/function/{argument}")
.Add<DTO2>("/service/commonsegment/{Function*}")
the mapping for DT1 is the "basic" mapping, one URL correspond to a DTO.
in DTO2 you will need a key called "Function" that will give you the name of the first "non-common" segment of the URL, any other segments preset in the URL will be mapped to your DTO2 if possible (if there is a matching property on it). This way you're open to new functions/arguments without changing the web server itself, only the backing implementation (that could/shlould be located on a external dll).
I hope this helps.
Related
I am coming from more of a .NET background and need to make some changes to a very old VB6 application.
The .NET equivalent of what I'm trying to do now in VB6 is, define a (model) class with 3 properties
public class MyClass
{
public string Ref { get; set; }
public string OldNumber { get; set; }
public string NewNumber { get; set; }
}
In .NET I would then call a stored procedure to return a set of results (there could be a few thousand records) and assign them to, for example, an instance of List<MyClass>.
I could then, whenever I need to, attempt to find an item within this List, where the 'Ref' property is 'blah', and use this item/its other properties (OldNumber and NewNumber).
However, in VB6, I don't know how this same process is best achieved. Can anyone please help?
If you are using ADO you can cache results by querying into a static cursor client-side Recordset and then disconnecting it.
You can use Sort, Find, Filter, etc. and move through the rows as needed. You can even improve searches by building a local index within the Recordset after opening and disconnecting it by using the Field object's Optimize dynamic property. See:
Optimize Property-Dynamic (ADO)
I have an application with a plugin architecture using MEF. For every exported part there is an attribute with the part's name, and I want to have the names translated, because I use these strings to display the available parts in ListBoxes (or the like).
So, I tried to set the 'Name = Strings.SomeText" in the [Export] annotation, but I get the following error:
"An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type"
Is there a solution to this? I find the use of the Metadata very useful (I do lazy loading) and I would not want to redesign everything just to get a few texts translated.
Any ideas? Thanks.
Unfortunately you can't directly provide the translated text to the attributes because an attribute can only contain data that is known at compile time. So you will need to provide some compile time constant value that you can later use to look up the translated test.
One solution would be to pass the resource name to the attribute. Then when you want to display the translated text you grab the resource name, look up the text in the resources and display the result.
For instance your attribute could look something like:
[Export(Name = "SomeText")]
public class MyExport
{
}
Then when you want to display the string you load the resources from the assembly that defines the export and you extract the actual text from the loaded resources. For instance like this (as borrowed from another answer):
var assembly = typeof(MyExport).Assembly;
// Resource file.. namespace.ClassName
var rm = new ResourceManager("MyAssembly.Strings", assembly);
// exportName contains the text provided to the Name property
// of the Export attribute
var text = rm.GetString(exportName);
The one obvious drawback about this solution is that you lose the type-safety that you get from using the Strings.SomeText property.
--------- EDIT ---------
In order to make it a little easier to get the translated text you could create a derivative of the ExportAttribute which takes enough information to extract the translated text. For example the custom ExportAttribute could look like this
public sealed class NamedExportAttribute : ExportAttribute
{
public NamedExportAttribute()
: base()
{
}
public string ResourceName
{
get;
set;
}
public Type ResourceType
{
get;
set;
}
public string ResourceText()
{
var rm = new ResourceManager(ResourceType);
return rm.GetString(ResourceName);
}
}
Using this attribute you can apply it like this
[NamedExport(
ResourceName = "SomeText",
ResourceType = typeof(MyNamespace.Properties.Resources))]
public sealed class MyClass
{
}
Finally when you need to get the translated text you can do this
var attribute = typeof(MyClass).GetCustomAttribute<NamedExportAttribute>();
var text = attribute.ResourceText();
Another option is to use the DisplayAttribute
Id like to firstly apologise for what may appear to be a stupid question but im confused regarding the following.
Im writting a class library which will not be running on the UI thread. Inside the CL i need an array which im going populate with data received from a stored procedure call. I then need to pass this data back to the UI thread via an event.
Originally i was going to write the following.
public class ColumnInformation
{
public string[] columnHeaderNames;
public string[] columnDataTypes;
}
but im pretty sure that would be frowned upon and i instead should be using properties.
public class ColumnInformation
{
public string[] columnHeaderNames {get; set;}
public string[] columnDataTypes {get; set;}
}
but then i came across the following.
MSDN
so am i correct in assuming that i should actually declare this as follows:
public class ColumnInformation
{
private string[] _columnHeaderNames;
public Names(string[] headerNames)
{
_columnHeaderNames = headerNames;
}
public string[] GetNames()
{
// Need to return a clone of the array so that consumers
// of this library cannot change its contents
return (string[])_columnHeaderNames.Clone();
}
}
Thanks for your time.
If your concern is the guideline CA1819: Properties should not return arrays,
It will be same whether you are exposing Array as a Public Field, or Property (making readonly does not matter here). Once your original Array is exposed, its content can be modified.
To avoid this, as the link suggest, make Field private, and return Clone from the Getter.
However major concern is that there may be multiple copies of your array if retrieved many times. It is not good for performance and synchronization.
Better solution is ReadOnlyCollection.
Using ReadOnlyCollection, you can expose the collection as read only which cannot be modified. Also any changes to underlying collection will be reflected.
Trying to implement a domain service in a SL app and getting the following error:
Parameter 'spFolderCreate' of domain method 'CreateSharePointFolder' must be an entity type exposed by the DomainService.
[EnableClientAccess()]
public class FileUploadService : DomainService
{
public void CreateSharePointFolder(SharePointFolderCreate spFolderCreate)
{
SharePointFolder spf = new SharePointFolder();
spf.CreateFolder_ClientOM(spFolderCreate.listName, spFolderCreate.fileName);
}
[OperationContract]
void CreateSharePointFolder(SharePointFolderCreate spFolderCreate);
[DataContract]
public class SharePointFolderCreate
{
private string m_listName;
private string m_fileName;
[DataMember]
public string listName
{
get { return m_listName; }
set { m_listName = value; }
}
[DataMember]
public string fileName
{
get { return m_fileName; }
set { m_fileName = value; }
}
}
So am I missing something simple here to make this all work?
It may be that the framework is inferring the intended operation because you have the word "Create" prefixing the function name (CreateSharePointFolder). Details of this behaviour can be found here
Although that is all fine for DomainServices and EntityFramework, following the information in that article, it can be inferred that methods beginning "Delete" will be performing a delete of an entity, so must accept an entity as a parameter. The same is true for "Create" or "Insert" prefixed methods. Only "Get" or "Select" methods can take non-entity parameters, making it possible to pass a numeric id (for example) to a "Get" method.
Try changing your method name temporarily to "BlahSharePointFolder" to see if it is this convention of inferrance that's causing your problem.
Also, as there is no metadata defined for your SharePointFolderCreate DC, you might need to decorate the class (in addition to the [DataContract] attribute) with the [MetadataType] attribute. You will see how to implement this if you used the DomainServiceClass wizard and point to an EF model. There is a checkbox at the bottom for generating metadata. Somewhere in your solution.Web project you should find a domainservice.metadata.cs file. In this file, you will find examples of how to use the [MetadataType] attribute.
For the RIA WCF service to work correctly with your own methods, you need to ensure that all entities existing on the parameter list have at least one member with a [Key] attribute defined in their metadata class, and that the entity is returned somewhere on your DomainService in a "Get" method.
HTH
Lee
I know this must be an age-old, tired question, but I cant seem to find anything thru my trusty friend (aka Google).
I have a .net 3.5 c# winforms app, that presents a user with a login form on application startup. After a successful login, I want to run off to the DB, pull in some user-specific data and hold them (in properties) in a class called AppCurrentUser.cs, that can thereafer be accessed across all classes in the assembly - the purpose here being that I can fill some properties with a once-off data read, instead of making a call to the DB everytime I need to. In a web app, I would usually use Session variables, and I know that the concept of that does not exist in WinForms.
The class structure resembles the following:
public class AppCurrentUser {
public AppCurrentUser() { }
public Guid UserName { get; set; }
public List<string> Roles { get; set; }
public string Firstname { get; set; }
public string Lastname { get; set; }
}
Now, I have some options that I need some expert advice on:
Being a "dumb" class, I should make the properties non-static, instantiate the class and then set the properties...but then I will only be able to access that instance from within the class that it was created in, right?
Logically, I believe that these properties should be static as I will only be using the class once throughout the application (and not creating new instances of it), and it's property values will be "reset" on application close. (If I create an instance of it, I can dispose of it on application close)
How should I structure my class and how do I access its properties across all classes in my assembly? I really would appreciate your honest and valued advice on this!!
Thanks!
Use the singleton pattern here:
public class AppUser
{
private static _current = null;
public static AppUser Current
{
get { return = _current; }
}
public static void Init()
{
if (_current == null)
{
_current = new AppUser();
// Load everything from the DB.
// Name = Dd.GetName();
}
}
public string Name { get; private set; }
}
// App startup.
AppUser.Init();
// Now any form / class / whatever can simply do:
var name = AppUser.Current.Name;
Now the "static" things are thread-unsafe. I'll leave it as an exercise of the reader to figure out how to properly use the lock() syntax to make it thread-safe. You should also handle the case if the Current property is accessed before the call to Init.
It depends on how you setup your architecture. If you're doing all your business logic code inside the actual form (e.g. coupling it to the UI), then you probably want to pass user information in as a parameter when you make a form, then keep a reference to it from within that form. In other words, you'd be implementing a Singleton pattern.
You could also use Dependency Injection, so that every time you request the user object, the dependency injection framework (like StructureMap) will provide you with the right object. -- you could probably use it like a session variable since you'll be working in a stateful environment.
The correct place to store this type of information is in a custom implementation of IIdentity. Any information that you need to identify a user or his access rights can be stored in that object, which is then associated with the current thread and can be queried from the current thread whenever needed.
This principal is illustrated in Rocky Lhotka's CLSA books, or google winforms custom identity.
I'm not convinced this is the right way but you could do something like this (seems to be what you're asking for anyway):
public class Sessions
{
// Variables
private static string _Username;
// properties
public static string Username
{
get
{
return _Username;
}
set
{
_Username = value;
}
}
}
in case the c# is wrong...i'm a vb.net developer...
then you'd just use Sessions.USername etc etc