Web: Random Notes

URL Paths

Two types of Paths:

• Absolute - starts with a leading slash
• Relative - does not start with slash. Location depends on where you are using them

default.asp is: /pages/default.asp - if called from /pages/linktool.asp

Two special directory names:
. means current directory
.. means parent directory

../default.asp is /pages/default.asp if called from /pages/tools/linktools.asp
../../default.asp is  /pages/default.asp if called from /pages/admin/tools/linktools.asp

~ tilde means root of the application
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Nullable value types

private int? _copid;
protected double? d = 5;

The variable can be assigned "null". Normally primitives like "int" and "double" can't be null.

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Null coalescing operator

x = y ?? z

x is assigned y's value. If y is null, then it's assigned z's value.

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TryParse Method

Syntax: public static bool TryParse(string s, out int result)


if ( int.TryParse( itemId, out parsedItemId ) && parsedItemId > 0 )

Meaning: Parse itemId, assign it to parsedItemID as int. If parsedItemID is int and greater than 0 then...

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(if) ? then : else

var objectInstance = condition ? foo : bar;

userType = user.Type == 0 ? "Admin"
         : user.Type == 1 ? "User"
         : user.Type == 2 ? "Employee"
         : "The default you didn't specify";


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Web.Config - Handling errors

Default value = RemoteOnly - which shows a pretty error page to remote users.

<system.web>
<customErrors mode="On">
</system.web>

Error message:
Error. An error occurred while processing your request.

Error view - just a razor view where you can modify it to include other information.
Views > Shared > Error.cshtml