To overrule default dynamic tracks, two changes must be made.

1. Create a class that implements the IPageOrder interface found in the Altinn.App.Core.Features.PageOrder namespace.
   You can name and place the file in any folder you like within your project, but we suggest you use meaningful namespaces like in any other .Net project.

    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Altinn.App.Core.Features.PageOrder;
    using Altinn.App.Core.Models;
    using Altinn.App.Models;
   
    namespace Altinn.App.AppLogic.Custom;
   
    {
        public class CustomOrder : IPageOrder
        {
            /// <inheritdoc />
            public async Task<List<string>> GetPageOrder(AppIdentifier appIdentifier, InstanceIdentifier instanceIdentifier, string layoutSetId, string currentPage, string dataTypeId, object formData)
            {
                List<string> pageOrder = new List<string>();
   
                // Implement your logic here.
   
                return await Task.FromResult(pageOrder);
            }
   
        }
   
    }
   

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2. Register you custom implementation in the _Program.cs_ class
```C#
services.AddTransient<IPageOrder, CustomOrder>();

This ensuers your custom code is known to the application and that it will be executed.

```

2. Register you custom implementation in the Program.cs class

   services.AddTransient<IPageOrder, CustomOrder>();
   

   This ensures your custom code is known to the application and that it will be executed.

master

The interface contains a method with the name GetPageOrder. The expected output from this is a sorted list with the names of the relevant pages in the application.

The function provides a number of parameters that can be useful if you are using form data or other information about the user to trigger the dynamic tracks.

• appIdentifier Contains organization and app name for the application

• instanceIdentifier Contains InstanceOwnerPartyId and InstanceGuid. If the application is stateless the object will be blank (InstanceIdentifier.NoInstance). If GetInstanceId is called on an InstanceIdentifier.NoInstance, an exception will be thrown.

• layoutSetId If your app defines multiple layout sets, the id on the layout set in question will be submitted. If the application does not have a layout set, this string will be empty. Based on this parameter the default page order defined in the application can be retrieved.

List<string> pageOrder = new List<string>();

if (string.IsNullOrEmpty(layoutSetId))
{
    pageOrder = _appResourcesService.GetLayoutSettings().Pages.Order;
}
else
{
    pageOrder = _appResourcesService.GetLayoutSettingsForSet(layoutSetId).Pages.Order;
}

This requires that the service IAppResources is made available in the class. When the service is already available through dependency injected into the class, only two steps are required:

1. Create a private variable in the state of the class

private readonly IAppResources _appResourcesService;

2. Define a constructor that takes in IAppResources and initializes the private variable that was created in step 1.

public CustomOrder(IAppResources appResourcesService)
{
    _appResourcesService = appResourcesService;
}

• CurrentPage The page you want to navigate from will be specified in this parameter.

• FormData contains the form data. This can easily be worked with as an object by casting it to the right type Skjema skjema = (Skjema)formdata;. Here, the C# model’s name is Skjema, but for your application the name could be different. You can check this by finding the class name of the C# file in the App/models folder.

In the file App.cs one must override the method that retrieves the default order of pages defined in Settings.json This is done by adding the below function in App.cs. The expected output from this method is a capitalized list containing the name of the relevant pages in the application.

/// <inheritdoc />
public override async Task<List<string>> GetPageOrder(string org, string app, int instanceOwnerId, Guid instanceGuid, string layoutSetId, string currentPage, string dataTypeId, object formData)
{
    List<string> pageOrder = new List<string>();
    // Implement your own logic here
    return pageOrder;
}

The function receives several parameters that can be useful if you are going to use form data or other information about the end user to calculate the track selection.

• layoutSetId If your app defines several layout sets, the id of the current layout set is submitted. If the application does not have a layout set, this string will be empty. Based on this parameter one can retrieve the default page order defined in the application:

List<string> pageOrder = new List<string>();
if (string.IsNullOrEmpty(layoutSetId))
{
    pageOrder = _appResourcesService.GetLayoutSettings().Pages.Order;
}
else
{
    pageOrder = _appResourcesService.GetLayoutSettingsForSet(layoutSetId).Pages.Order;
}

This assumes that the service IAppResources is made available in App.cs file. As the service is already dependency injected into the class, only two steps are required.

1. Create a private variable in the state of the class.

private readonly IAppResources _appResourcesService;

2. Define the new private variable equal to the service passed in the constructor of App.cs.

 _appResourcesService = appResourcesService;

CurrentPage The page you want to navigate from must be specified in this parameter.

• FormData contains the form data. It can easily be worked with as an object by casting it to the correct type Form form = (Form)formData;. In this case C# model for the form data is called `Form’ for your application, it can be another name. You can check this by finding the class name of the C# file in the App/models folder.