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#4 Use Shared C# Code
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Use Shared C# Code

The best way shared C# helpers:

  • public functions returning strings, objects, ints etc.
  • public functions returning html using RazorBlade

This is recommended in v12 and above as it works in Dnn ✅ and Oqtane ✅

You share them by placing them into a separate CS file (just remember to mark them public). This lets you put a bunch of tiny helpers into a helpers-library and use them from elsewhere.

In strong-typed code we place these in the AppCode folder, and get them using the standard new MyHelper(). In scenarios where the helper needs to know the full context, use GetService<MyHelper>().

The samples can differ based on your Razor base class or if you're running an old version.
Selected: Strong-Typed (2sxc 17.06+) Switch to Typed (2sxc 16+) Switch to Dynamic (Razor14 or below)

Using Shared Helpers / Libraries

The example takes a cshtml file using GetService<...>()and uses it as a central helpers library. The helper PreviewWithLightbox will generate a thumbnail, include Fancybox3 (only the first time) and ensure you can click it for a full image.

⬇️ Result | Source ➡️


@inherits Custom.Hybrid.RazorTyped
@using AppCode.Helpers

@{
  // Use GetService, since the Fancybox requires standard helpers/context
  // such as the Kit object
  var lightbox = GetService<FancyboxService>();
}
@* Url to app root folder is in App.Folder.Url *@
@lightbox.PreviewWithLightbox(App.Folder.Url + "/app-icon.png")
<br>
@lightbox.PreviewWithLightbox(App.Folder.Url + "/assets/img-resize/basic-banner.png", 200, 100)

Source Code of FancyboxService.cs

using System.Linq;
using ToSic.Razor.Blade;
using ToSic.Sxc.Data;
using ToSic.Sxc.Images;

namespace AppCode.Helpers
{

  public class FancyboxService: Custom.Hybrid.CodeTyped
  {
    // Create an image which opens a larger version in a lightbox
    public IHtmlTag PreviewWithLightbox(string url, int width = 100, int height = 100, string classes = "", string label = null, bool figure = true)
    {
      // Add fancybox JS to the page (will only add once, no matter how often it's called)
      Kit.Page.Activate("fancybox4"); 

      var imgResizeSettings = Kit.Image.Settings(width: width, height: height);
      var imgOrPic = Kit.Image.Img(url, settings: imgResizeSettings);
      // Create the link tag with the image inside
      var html = Kit.HtmlTags.A()
        .Data("fancybox", "gallery")
        .Href(url)
        .Class(classes)
        .Data("caption", label)
        .Wrap(imgOrPic);

      return html;
    }
  }
}

When you need a function in many places, it's best to put it into an own cs file.

The example takes a cshtml file with a QrPath function returning the url to a qr-code. It then accesses it using GetService<...>().

⬇️ Result | Source ➡️

Hello from lib: Hello!
@inherits Custom.Hybrid.RazorTyped
@using ToSic.Razor.Blade
@using AppCode.Helpers

@{
  // Use standard new in Strongly Typed Code
  var lib = GetService<QrHelper>();
}
<div>Hello from lib: @lib.SayHello()</div>
<div>
  <img loading="lazy" src='@lib.QrPath("https://2sxc.org")' width="75px">
</div>

Source Code of QrHelper.cs

namespace AppCode.Helpers
{
  /// <summary>
  /// Helper functions. Must inherit from CodeTyped since it uses
  /// the App object.
  /// </summary>
  public class QrHelper: AppCode.Services.ServiceBase
  {

    public string SayHello() {
      return "Hello!";
    }

    public string QrPath(string link) {
      // path to qr-code generator
      var qrPath = "//api.qrserver.com/v1/create-qr-code/?color={foreground}&bgcolor={background}&qzone=0&margin=0&size={dim}x{dim}&ecc={ecc}&data={link}"
        .Replace("{foreground}", App.Settings.QrForegroundColor.Replace("#", ""))
        .Replace("{background}", App.Settings.QrBackgroundColor.Replace("#", ""))
        .Replace("{dim}", App.Settings.QrDimension.ToString())
        .Replace("{ecc}", App.Settings.QrEcc)
        .Replace("{link}", link);
      return qrPath;
    }

  }
}

Reuse Code with .cs Files

Starting with 2sxc 10.01 CreateInstance() can also be used with .cs files, from both razor pages as well as WebApi controllers. This allows you to create shared code which can be used in Razor and WebApi controllers.

Note that in 2sxc 16.05 we recommend you use GetCode() instead.

The example takes a cs file with shared code, but gets the class Second.

⬇️ Result | Source ➡️

Hello from SecondFunctionsBasic in the FunctionsBasic file:
Hello from the second class! 
@inherits Custom.Hybrid.RazorTyped
@using AppCode.Helpers

@{
  var lib = new SecondFunctionsBasic();
}
<div>
  Hello from <code>SecondFunctionsBasic</code> in the <code>FunctionsBasic</code> file:
  <br>
  @lib.SayHello()
</div>

Source Code of FunctionsBasic.cs

namespace AppCode.Helpers {
  public class FunctionsBasic {

    public string SayHello() {
      return "Hello from shared functions!";
    }
  }

  // Example for another class in the same file
  public class SecondFunctionsBasic {
    public string SayHello() {
      return "Hello from the second class!";
    }
  }
}

Often you may need context - like the Dnn or App objects. We made this easy by defining a base class you can inherit from, called Custom.Hybrid.Code14 (previously ToSic.Sxc.Dnn.DynamicCode). If you use that as your base-class, all existing context is automatically attached, allowing you to access variables like App.

⬇️ Result | Source ➡️

@inherits Custom.Hybrid.RazorTyped
@using AppCode.Helpers

@{
  var powerLib = GetService<QrHelper>(); // GetCode("FunctionsWithContext.cs");
}
<div>
  <img loading="lazy" src='@powerLib.QrPath("https://2sxc.org")' width="75px">
</div>

Source Code of QrHelper.cs

namespace AppCode.Helpers
{
  /// <summary>
  /// Helper functions. Must inherit from CodeTyped since it uses
  /// the App object.
  /// </summary>
  public class QrHelper: AppCode.Services.ServiceBase
  {

    public string SayHello() {
      return "Hello!";
    }

    public string QrPath(string link) {
      // path to qr-code generator
      var qrPath = "//api.qrserver.com/v1/create-qr-code/?color={foreground}&bgcolor={background}&qzone=0&margin=0&size={dim}x{dim}&ecc={ecc}&data={link}"
        .Replace("{foreground}", App.Settings.QrForegroundColor.Replace("#", ""))
        .Replace("{background}", App.Settings.QrBackgroundColor.Replace("#", ""))
        .Replace("{dim}", App.Settings.QrDimension.ToString())
        .Replace("{ecc}", App.Settings.QrEcc)
        .Replace("{link}", link);
      return qrPath;
    }

  }
}

The mechanism above also works in WebApi Controllers (if you have 2sxc 10.01+). Note that specifically in WebApi you can only use GetCode(...) for .cs files.

⬇️ Result | Source ➡️

Click to see the result of a WebApi call with the shared code: 

@inherits Custom.Hybrid.RazorTyped
@using ToSic.Razor.Blade

<p>
  Click to see the result of a WebApi call with the shared code:
  <button type="button" class="btn btn-primary" onclick="callApiWithSharedCode(this)">
    Call WebApi
  </button>
</p>

<script>
  function callApiWithSharedCode(context) {
    $2sxc(context).webApi.fetchJson('app/auto/api/sharedcode/hello')
      .then(function (results) {
        console.log(results);
        alert(results);
      });
    return false;
  }
</script>

Source Code of SharedCodeController.cs

// Add namespaces for security check in Oqtane & DNN despite differences in .net core/.net Framework
// If you only target one platform, you can remove the parts you don't need
#if NETCOREAPP
using Microsoft.AspNetCore.Authorization; // .net core [AllowAnonymous] & [Authorize]
using Microsoft.AspNetCore.Mvc;           // .net core [HttpGet] / [HttpPost] etc.
#else
using System.Web.Http;                    // .net 4.5 [AllowAnonymous] / [HttpGet]
using DotNetNuke.Web.Api;                 // [DnnModuleAuthorize] & [ValidateAntiForgeryToken]
#endif

[AllowAnonymous]                          // all commands can be accessed without a login
[ValidateAntiForgeryToken]                // protects API from users not on your site (CSRF protection)
public class SharedCodeController : Custom.Hybrid.Api14 // see https://r.2sxc.org/CustomWebApi
{
  [HttpGet]
  [AllowAnonymous]
  public string Hello()
  {
    var shared = CreateInstance("../shared/FunctionsBasic.cs");
    return shared.SayHello();
  }
}

// The next line is for 2sxc-internal quality checks, you can ignore this
// 2sxclint:disable:no-dnn-namespaces - 2sxclint:disable:no-web-namespace

Source Code of FunctionsBasic.cs

// Important notes: 
// - This class should have the same name as the file it's in
public class FunctionsBasic {

  public string SayHello() {
    return "Hello from shared functions!";
  }
}

// Example for another class in the same file
public class Second {
  public string SayHello() {
    return "Hello from the second class!";
  }
}

 

 

Reuse Shared Templates with Html.Partial and MyModel
#4 Use Shared C# Code
Working with Page URL Parameters