Sometimes you would like to check passwords to be conformant with some rules. At least one digit, one letter is a common one. Here is the regexp for this:
(?=.*?[0-9])(?=.*?[A-Za-z]).+
Allows special characters and makes sure at least one number and one letter.
Update:
(?=.*?[0-9])(?=.*?[A-Za-z])(?=.*[^0-9A-Za-z]).+
Demands at least one letter, one digit and one special-character. The first one does not demand special chars, only allows them.
Enums are handy. But they do not allow you have easy Text description on them.
How about using DisplayAttribuite on enum values and have that text in a drop-down? Easy!
/// <summary>
/// Creates a SelectList from Enum, taking Description values from Enum fields
/// Taken from here: http://stackoverflow.com/a/3705387/809357
/// </summary>
public static SelectList ToSelectListWithDisplayName<T>(this T enumeration, string selected = "")
{
var source = Enum.GetValues(typeof(T));
var items = new Dictionary<object, string>();
var displayAttributeType = typeof(DisplayAttribute);
foreach (var value in source)
{
FieldInfo field = value.GetType().GetField(value.ToString());
if (field == null) continue;
DisplayAttribute attrs = (DisplayAttribute)field.GetCustomAttributes(displayAttributeType, false).FirstOrDefault();
if (attrs != null)
{
items.Add((int)value, attrs.GetName());
}else // in case Description attribute is not available, we fall back to the default name
{
items.Add((int)value, value.ToString());
}
}
return new SelectList(items, "Key", "Value", selected);
}
Also you can get just on Display Name for one Enum Value:
public static string GetDisplayName(this Enum value)
{
FieldInfo field = value.GetType().GetField(value.ToString());
if (field == null)
return String.Empty;
object[] attribs = field.GetCustomAttributes(typeof(DisplayAttribute), true);
if(attribs.Length > 0)
{
return ((DisplayAttribute)attribs[0]).GetName();
}
return value.ToString();
}
Creating custom attribute is pretty simple really, just follow the example. You need to return MvcHtmlString – that is string with your html to be displayed on a page – this will not be escaped.
public static MvcHtmlString DisplayWithNameFor<TModel, TProperty>(
this HtmlHelper<TModel> htmlHelper,Expression<Func<TModel, TProperty>> expression)
{
ModelMetadata metaData = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
if (metaData.Model == null)
{
return MvcHtmlString.Create(String.Empty);
}
string html = "<div class=\"display-label\">";
html += htmlHelper.LabelFor(expression).ToString();
html += "</div><div class=\"display-field\">";
html += htmlHelper.DisplayFor(expression).ToString();
html += "</div>";
return MvcHtmlString.Create(html);
}
Whenever you need a page to return to the previous page when you get an form submit or some other action, this can be used:
Have a base controller that is inherited by all your controllers. That is always a good idea – you can easily add things that work site-wide.
In you base controller have a OnActionExecuting overriden – here we are going to store the previous page.
Something like this:
public abstract partial class MyController : Controller
{
public ActionResult RedirectToPrevious(String defaultAction, String defaultController)
{
if (Session == null || Session["PrevUrl"] == null)
{
return RedirectToAction(defaultAction, defaultController);
}
String url = ((Uri)Session["PrevUrl"]).PathAndQuery;
if (Request.Url != null && Request.Url.PathAndQuery != url)
{
return Redirect(url);
}
return RedirectToAction(defaultAction, defaultController);
}
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var httpContext = filterContext.HttpContext;
if (httpContext.Request.RequestType == "GET"
&& !httpContext.Request.IsAjaxRequest()
&& filterContext.IsChildAction == false) // do no overwrite if we do child action.
{
// stop overwriting previous page if we just reload the current page.
if (Session["CurUrl"] != null
&& ((Uri)Session["CurUrl"]).Equals(httpContext.Request.Url) )
return;
Session["PrevUrl"] = Session["CurUrl"] ?? httpContext.Request.Url;
Session["CurUrl"] = httpContext.Request.Url;
}
}
}
Now, as I figured, it is not the best idea for redirecting everything by default. For validation purposes you would like not to redirect
Then you can reference Session[“PrevUrl”] in controllers, but there is a better way of doing it – create attribute!
public class RedirectToPreviousPageAttribute : ActionFilterAttribute
{
///
///
public override void OnResultExecuted(ResultExecutedContext filterContext)
{
var httpContext = filterContext.HttpContext;
if (httpContext.Session == null || httpContext.Session["PrevUrl"] == null)
{
base.OnResultExecuted(filterContext);
return;
}
String url = ((Uri)httpContext.Session["PrevUrl"]).PathAndQuery;
if (httpContext.Request.Url != null && httpContext.Request.Url.PathAndQuery != url)
{
httpContext.Response.Redirect(url);
}
base.OnResultExecuted(filterContext);
}
}
And now, wherever you are put this attribute on a controller action (or entire controller), it will redirect to the previous page:
[HttpPost]
public virtual ActionResult Edit(Model model)
{
if (!ModelState.IsValid)
{
return View(model);
}
_repository.InsertOrUpdate(model);
_repository.Save();
return RedirectToPrevious("Index", "Controller");
}
Voilà! Good to go!
I keep forgetting the syntax for shorthand of if-then-else.
condition ? expression_for_true : expression_for_false
Example
return (MyBlogPosts.Count() != 0) ? System.IO.File.Create("totalPosts.txt") : false;
Ninject is very cool and lightweight DI container.
But you can not always inject objects through constructor – sometimes you must have parameter-less constructor, like in MvcApplication object.
In that case you can use DependencyResolver from System.Web.Mvc namespace from System.Web assembly
_userDataService = DependencyResolver.Current.GetService<IUserDataService>();
Unfortunately MSDN documentation does not have much, only link to this blog post: http://bradwilson.typepad.com/blog/2010/10/service-location-pt5-idependencyresolver.html
In Razor compiler directives do not work, cause Razor Views are not compiled.
So this would not work:
@{ #if DEBUG}
@{#else}
@{#endif}
But you can trick that thing into submission, thanks to this StackOverflow topic
A better, more generic solution is to use an extension method, so all views have access to it:
public static bool IsReleaseBuild()
{
#if DEBUG
return false;
#else
return true;
#endif
}
You can then use it like follows in any view (razor syntax):
@if(IsReleaseBuild())
Everybody is talking how good the T4 templates, but nobody tells you how to generates the bloody things.
In VS2012 if you open command window (View-> Other Windows -> Command Window) and execute
TextTransformation.TransformAllTemplates – that should do the trick.
If you would like a button for that – add Build Toolbar Panel and it should contain “Transform All Templates” button.
Or you can install Chirpy and configure it to do T4MVC for you on every build:
I hate CSS with passion. How many fucking steps do you need to take to make things aligned in the center of a container?
You need to make sure your outside container is set to the required width. Usually 100%.
Then you need to center the loose text by text-align:center;
Then you need to make internal container to have set width (sic!) and give it margins to “auto”.
I understand the concept behind this. But show me a man who came up with idea of setting a margin to auto to be align a container. I’ll shoot him in a face!
blah-bloody-blah! this is centered with no problem.and this just does not get into center unless you set margins.
If Entity Framework (version below 5.1) on your attempt to Update-Database gives you error of “Object reference not set”, change the default start-up project to MVC project, not anything else. And try the same thing again.
This reported to be fixed in the latest 5.x version of EF, but it is a little annoyance just now.
p.s. This can be eased with parameter: -StartupProject “helloMVC” when running Update-Database command