article asp.net core

How To Route Constraints In ASP.NET Core

How To Route Constraints In ASP.NET Core

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CheapASPNETHostingReview.com | Best and cheap ASP.NET Core. Route Constraints can be a handy way to distinguish between similar route names, and in some cases, pre-filter out “junk” requests from actually hitting your actions and taking up resources. A route constraint can be as simple as enforcing that an ID that you expect in a URL is an integer, or as complicated as regex matching on strings.

An important thing to remember is that route constraints are not a way to “validate” input. Any server side validation you wish to occur should still happen regardless of any route constraints set up. Importantly, know that if a route constraint is not met than a 404 is returned, rather than a 400 bad request you would typically expect to see from a validation failure.

Type Constraints

Type constraints are a simple way to ensure that a parameter can be cast to a certain value type. Consider the following code :

At first glance you might assume that if you called “/api/controller/abc” that the route would not match – It would make sense since the id parameter is an integer. But infact what happens is that the route is matched and the id is bound as 0. This is where route constraints come in. Consider the following :

Now if the id in the URL is not able to be cast to an integer, the route is not matched.

You can do this type of constraints with int, float, decimal, double, long, guid, bool and datetime.

Size Constraints

There are two types of “size” constraints you can use in routes. The first is to do with strings and means you can set a minimum length, max length or even a range.

This sets a minimum length for the string value. You can also use maxlength to limit the length.

Alternatively, you can set how many characters a string can be within a range using the length property.

While that’s great for string variables, for integers you can use the min/max/range constraints in a similar fashion.

Regex Constraints

Regex constraints are a great way to limit a string input. By now most should know exactly what regex is so there isn’t much point doing a deep dive on how to format your regex, just throw it in as a constraint and away it goes.

It is worth noting there for whatever reason, the .NET core team added another handy “quick” way of doing alpha characters only instead of regex. There you can just use the constraint of “alpha”.

How To Create Help Desk Web Application using ASP.NET Core

How To Create Help Desk Web Application using ASP.NET Core

CheapASPNETHostingReview.com | Best and cheap ASP.NET Core hosting. Suppose you work for a small to midsize company that employs 50-100 workers. The Help Desk — a subsidiary of the Information Services Division — is in charge of trouble tickets regarding general PC issues such as email, viruses, network issues, etc. Initially, the Help Desk team stored this information in Excel spreadsheets, but as the company has grown, managing these spreadsheets has become tedious and time consuming.

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The Help Desk has asked you to devise a more efficient solution that could be developed internally, saving the company money. As you start to think about it, the following requirements are apparent: fields for the submitter’s first and last name, as well as their email address. You’ll also need combo boxes for indicating ticket severity (low, medium, high), department, status (new, open, resolved), employee working on the issue, as well as an area for comments. Of all the solutions available, creating an internal help desk Web application with ASP.NET is relatively simple.

In the following article, we’ll see how to implement these features in an ASP.NET help desk Web application using a database-driven approach,
Creating the JavaScript File
Because creating the JavaScript file is the easiest of the work left, we’ll do this next. From the Solution Explorer, follow these steps:

Creating the Help Desk Class

Now that we have our data coming in, we need to be able to record a help desk ticket submission. We need to create an event handler in a class to handle it. Let’s first create a help desk class by doing the following:

  •     Right click the project solution.
  •     Choose Add>New Item.
  •     In the Add New Item window, select Class.cs.
  •     In the name text field, type “HelpDesk” and then click Add.

Double click HelpDesk.cs from the Solution Explorer, which will show the empty class as shown below:

We need to import three libraries as shown below:

The first library (System.Data) allows us to work with stored procedures in ADO.NET, the second (System.Configuration) allows us to reference a connection key from configuration file and the last (System.Data.SqlClient) one allows us to connect to SQL Server.