I'm teaching myself ASP.NET MVC, and am trying to figure out where best to put a function which takes in an Models.Address instance and returns an IHtmlString instance which reads something like:
Line 1<br />
Line 2<br />
City, State
The string could be used in many places throughout my project, so I don't want to write it in one view and have to keep copy-pasting it or attaching that view: By the same logic attaching it to ViewData seems like a bad idea. However, the HtmlEncode method requires an instance of server, which means I can't add the function to the model class either.
Is there a right place to put this - some sort of shared view? (does this belong in the master?) Or am I going about this all wrong?
My current best idea is to create a ViewModel with the method public IHtmlString FormatAddress(Address address, HttpServerUtility server), but I don't know if that's the ASP.NET MVC way to do it.
As this is presentation UI logic, the best place to put it is in a HtmlHelper class.
public static class HtmlHelper
{
public static HtmlString FormatAddress (this HtmlHelper, Address address)
{
string formattedAddress = // the formatted address...
return HtmlString.Create(formattedAddress);
}
}
then, from any view you simply call:
<%= Html.FormatAddress(address) %>
I usually create something like that as an Extension Method on a HelperExtensions class and then place that class in a Helpers folder at the top level of the site.
public static class HelperExtensions
{
public static Format(this Address address, HttpServerUtility server)
{
// Do the work to format here.
}
}
Related
Maybe a stupid question. C# 6.0 allows for string replacement using this syntax: $"string content {foo} {bar}". I would like to imitate this behavior in a class I've written for strings passed to it by default. The problem is that I am not sure how to access the public properties/variables. I am not sure if there is a way to access the properties using reflection or by passing this or this.Page to the constructor.
Figured it out:
public static object GetPropValue(object src, string propName)
{
return src.GetType().GetProperty(propName).GetValue(src, null);
}
object UID = GetPropValue(System.Web.HttpContext.Current.Handler, "UID");
I am new to Web Technology. I have a WebService called Sample. It references a dll with name Custom.dll. My WebMethod is returning a class from Custom.dll which is marked as Serialization.
// My custom class
[System.CodeDom.Compiler.GeneratedCodeAttribute("wsdl", "2.0.50727.3038")]
[SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(Namespace = "http://somthing-something.mydomain.com/")]
public class CustomClass
{
public string id;
public string key;
}
// My Web Service method
[WebMethod]
public CustomClass MyWsMethod()
{
return new CustomClass{id="id", key="Key"};
}
Also to mention, my webservice is a WCF Service and has a asmx file in it.
I am consuming this webservice in my application and service referenced my webservice as localhostWS. My Application also references Custom.dll. When I am calling my webservice method then I am not able to get back the Custom.CustomClass object. I am returning localhostWS.CustomClass and also I am not able cast it to Custom.CustomClass.
CustomClass custom = localhostWS.MyWsMethod();
Here custom object is of type localhostWS.CustomClass but I was expecting Custom.CustomClass.
Can any body suggest me whats happening here. Please let know if I need to provide any further information. I have tried enough to be clear in my question.
Edit
I must also mention this, it will great to achieve this without changing any Client side code. Due to reasons it will not be possible to change that. However any suggestions are welcome.
I'm building a site on the new Razor engine that comes with MVC 3 (and loving the new syntax!). However, I am at a loss about using public properties / constants with it. I know that with WebForms we could add a public property in code behind:
public string ImageFolder { get; set; }
I would like to define important variables in one global place that my views can access, starting with paths to CSS files and images:
#{
Layout = "~/Views/Shared/_Layout.cshtml";
var ContentFolder = "~/Content";
var CssFolder = ContentFolder + "/Stylesheets";
var ImageFolder = ContentFolder + "/Images";
}
I have tried putting the above code block in _Layout, as well as inside _ViewStart. However, accessing them from child views fails miserably. I thought of defining a public property in the above code block but it doesn't compile.
Solutions?
As far as I have seen, noone uses code behind with Razor.
I guess I should be able to inherit from the default view and define my properties there (as described on Stack).
But I'm strongly hoping that there should be an easier way to do something so simple?
I decided to follow yet another path, and extended UrlHelper to provide paths to all three folders I think I might need:
public static class ExtensionMethods
{
private const string ImagesFolder = "~/Images";
private const string StylesheetsFolder = "~/Stylesheets";
private const string ScriptsFolder = "~/Scripts";
public static string Images(this UrlHelper url)
{
return url.Content(ImagesFolder);
}
public static string Stylesheets(this UrlHelper url)
{
return url.Content(StylesheetsFolder);
}
public static string Scripts(this UrlHelper url)
{
return url.Content(ScriptsFolder);
}
}
All good to go... almost :-) I'm now wondering if there's a place where I would be able to define the using MyNamespace.Helper statement would go in order for these extension methods to be available application-wide. In the old days we would add an entry in web.config:
<system.web>
<pages>
<namespaces>
<add namespace="MyNamespace.Helper"/>
</namespaces>
</pages>
</system.web>
This doesn't seem to work with Razor :-( I tried adding a using statement in _ViewStart.cshtml but no luck either - the only way for my extension methods to be visible is to add a using statement on a particular page, which again isn't ideal.
Any suggestions? Have any of you seen an explanation of Razor's order of page parsing & delivery?
Your can create a folder "App_Code" and create a file "GlobalVal.cshtml".
bellow is a sample code in the file:
#functions{
public static readonly string __siteHome = "http://www.example.com";
public static readonly string __siteResource = "http://resource.example.com";
}
and bellow is a sample using it:
#GlobalVal.__siteHome
Use the PageData property:
#{
Layout = "~/Views/Shared/_Layout.cshtml";
PageData.Add("ContentFolder", "~/Content");
}
and inside _Layout.cshtml:
<%=PageData["ContentFolder"]%>
In _layout view
#{
App.AnyName = "abc";
}
In Inherit view
#{
var anyVariable = App.AnyName;
}
Just place the constants in a public module inside your app_code folder, or if you don't want to do that just create a clasas in app_code and use the using (imports) keyword to import the namespace (class name) in each view and you can use it that way.
Alternatively, if it makes sense to do so, just add them in your view model - remember, it might not make sense to add those vars to your model, but it can make sense to add them to your view model! This is what the view model is for, and this view model can grab the constant values from a public module or class or you can even set it in your actual view model itself, this way you will only define the values in one place and you don't need to use any namespace imports into each view :)
Let me know how it goes and if there is anything else I can do to help you out.
In vb.net but same as csharp and its easy to understand since it's vb.
Public class YourModel
// this is where you have the normal model you have... No big deal
End Class
...
// now you make the view model urself
...
Public class MyViewModel
Public MyNormalModel as YourModel
//notice we r declaring ur normal model as a variable, u can use a property instead
Public MyPathConstant1 as string = "abc"
Public MyPathConstant2 as string = "abc"
Public MyPathConstant3 as string = "abc"
End Class
Now, you gotta set the value of MyNormalModel to ur current model instance, although you can do that in ur controller, it's best practice to create a method inside the MyViewModel class that takes a copy of ur current model as argument and does the setting of MyNormalModel to the current model we just passed in the argument.
You can still make that call in your controller, but on another note, what people prefer to do is, instead of passing the whole normal model as a property, the just take the bits and pieces they need from the normal model and place them into the view (ie: you might just need half the properties in the normal model to be in the view model). This is because, remember, the view model will be passed to the view and they don't wanna pass things they wont use :). But this means you are going to need to set each of those properties one by one most likely (unless those exact ones are encapsulated in a sub class which usually doesn't happen by chance lol).
I kept it in one so you can just copy the normal model over in one shot for simplicity.
Now when you pass the view model to your view (MyViewModel) you will be able to use and access the normal model through the object notation and it's properties, eg... Model.MyNormalModel.Property1. Etc and do whatever you want with it in the view... Also, you can access the rest of your view model (the const values that we set) like this... Model.MyPathConstant1 and Model.MyPathConstant2 etc... So you have access to practically everything you want, ur normal model and whatever else you added later on all through what is now called your view model.
Please excuse typos -writing from and ipad lol. Let me know if this is making more sense.
You could use the built-in property of UrlHelper Content:
#Url.Content("~/Content/Stylsheets")
#Url.Content("~/Content/Images")
I'm a first-time user of the AOP features of Unity 2.0 and would like some advice. My goal is to be able to log method calls in an ASPX page, like so:
public partial class Page2 : Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
[Log]
private void Testing()
{
}
}
Here is the code for the LogAttribute:
public class LogAttribute : HandlerAttribute
{
public override ICallHandler CreateHandler(IUnityContainer container)
{
return new LogHandler(Order);
}
}
Now the LogHandler:
public class LogHandler : ICallHandler
{
public LogHandler(int order)
{
Order = order;
}
public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)
{
string className = input.MethodBase.DeclaringType.Name;
string methodName = input.MethodBase.Name;
string preMethodMessage = string.Format("{0}.{1}", className, methodName);
System.Diagnostics.Debug.WriteLine(preMethodMessage);
return getNext()(input, getNext);
}
public int Order { get; set; }
}
The problem I have is how to use the [Log] attribute. I've seen plenty of example of how to configure the interception settings, for example:
container.AddNewExtension<Interception>();
container.Configure<Interception>().SetDefaultInterceptorFor<ILogger>(new InterfaceInterceptor());
But this implies that I have an interface to intercept, which I don't. I have the ASPX page which uses the [Log] attribute.
so how can I configure Unity to make use of the [Log] attribute? I've done this before using PostSharp and would like to be able to use Unity to do the same.
Cheers.
Jas.
You're unfortunately not going to get this to work in an ASP.NET page with Unity interception.
Unity interception uses a runtime interception model. Depending on the interceptor you choose, you'll either get a subclass with virtual method overrides to call the call handlers (VirtualMethodInterceptor) or a separate proxy object (Interface or TransparentProxyInterceptor) which execute the call handlers and then forward to the real object.
Here's the issue - ASP.NET controls creation and calls to your page, and there's no easy way to hook into them. Without controlling the creation of the page object, you can't use the VirtualMethodInterceptor, because that requires that you instantiate a subclass. And you can't use the proxy version either, because you need ASP.NET to make calls through the proxy.
PostSharp gets around this because it's actually rewriting your IL at compile time.
Assuming you could hook into the creation of the page object, you'd have to use the VirtualMethodInterceptor here. It's a private method, so you want logging on "self" calls (calls from one method of the object into another method on the same object). The proxy-based interceptors can't see those, since the proxy is a separate instance.
I expect there is a hook somewhere to customize how ASP.NET creates object - BuildManager maybe? But I don't know enough about the details, and I expect it'll require some pretty serious hacking to get work.
So, how do you get around this? My recommendation (actually, I'd recommend this anyway) is to use the Model-View-Presenter pattern for your ASP.NET pages. Make the page object itself dumb. All it does is forward calls to a separate object, the Presenter. The Presenter is where your real logic is, and is independent of the details of ASP.NET. You get a huge gain in testability, and you can intercept calls on the presenter without all the difficulty that ASP.NET gives you.
i'm trying to work out the best method to perform logging in the application i'm currently developing.
right now, i have a Log table that stores the username, timestamp, action, controller, and a message. when a controller is instantiated, it gets the IoC info through Castle Windsor.
for example, my "Sites" controller is created as follows:
private ISitesRepository siteRepository;
private ILogWriter logWriter;
public SiteController(ISitesRepository siteRepository, ILogWriter logWriter)
{
this.siteRepository = siteRepository;
this.logWriter = logWriter;
}
and the log writer has a function that creates and inserts a log entry (WriteToLog). within the Sites controller's Edit and Create actions, it calls the WriteToLog function.
this is working and doing its job, but my question is- do i really need to set up each controller this way, passing through the ILogWriter interface/repository? it struck me that i could possibly set up a LogController, and just have that do the "heavy lifting" of writing to my logs.
that way, i wouldn't have to mess with the IoC stuff in every other controller. is it possible to execute an action on another controller (for example, a LogController-> WriteLog)? i'm not sure how would that be done without doing a redirect...
Could you pass by an abstract class? This abstract class having a static property referencing you log writer?
something like this
public abstract class BaseController
{
public static ILogWriter Logwriter{get;set;}
public static BaseController
{
Logwriter = YourFactory.GetLogwriter();
}
}
public class YourController:BaseController
{
public YourController(ISitesRepository siteRepository)
{
}
}
Ok, after much head scratching, i think i found an acceptable solution.
I implemented my logging action as a custom action filter as so:
public class LogAction : ActionFilterAttribute, IActionFilter
{
public LogLevel loglevel;
public string message;
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
ILogWriter logWriter = AppServiceFactory.Instance.Create<ILogWriter>();
logWriter.WriteToLog(
filterContext.ActionDescriptor.ControllerDescriptor.ControllerName,
filterContext.ActionDescriptor.ActionName,
loglevel,
filterContext.HttpContext.Timestamp,
filterContext.HttpContext.User.Identity.Name.ToString(),
message + "(id=" + filterContext.RouteData.Values["id"] + ")");
}
}
but i ran into a wall trying to get the IoC to work in a custom attribute filter. scouring stackoverflow and google searches, i found that it's sort of difficult to do, with talk about using different wrappers, action invokers, etc, which all seemed more complicated than i was really willing to deal with.
trying to learn more about IoC (i'm still very new at this), i found this article,
which really helped point me in the right direction. i added his sealed AppServiceFactory class with my WindsorControllerFactory, and it worked like a charm.
As i said, i'm very new with to MVC and this IoC stuff, so i'm not sure this is an ideal way of handling things- but it seems simple and it works so far. I'd welcome any comments or criticisms on handling it through this method.
UPDATE
Figured out a different way of doing this- created a function in my WebUI project as such:
public static class Loggers
{
public static void WriteLog(ControllerContext controllerContext, LogLevel logLevel, string message)
{
ILogWriter logWriter = AppServiceFactory.Instance.Create<ILogWriter>();
logWriter.WriteToLog(
controllerContext.RouteData.Values["controller"].ToString(),
controllerContext.RouteData.Values["action"].ToString(),
logLevel,
controllerContext.HttpContext.Timestamp,
controllerContext.HttpContext.User.Identity.Name.ToString(),
message);
}
}
now, wherever i want to log something, i can call
Loggers.WriteLog(
this.ControllerContext,
LogLevel.Membership,
"Removed role '" + role + "'" + " from user " + _userService.Get(id).UserName );
to write a record to the log. this gives me a lot more flexibility on my "message" content, and solves the problem of including logging in the global.asax file, which would've been difficult if not impossible using the attribute filters. i'll leave the rest, as it may be of use to someone else, but i think this is the way i'll go on this.
as usual, things are usually simpler in MVC than i original think they will be :)