ProjectReunion/specs/dynamicdependencies/sample-7.md

Sample 7 - LolzKitten app ordering Packages in PackageGraph

Contoso publishes framework packages. At runtime, LolzKittens wants to use Contoso's functionality as specified by the package dependencies defined when LolzKittens was installed. These framework packages are added to the process' package graph in a verify specific order:

• Muffins
• process' static package graph (if any)
• Waffles

The package dependencies are added to the package graph with specific 'rank' values to ensure the desired order.

The package graph is updated for the remainder of the process' lifetime (i.e. the package dependencies are not explicitly removed).

Win32

#include <MsixDynamicDependency.h>
#include <wil/resource.h>

HRESULT LoadPackageDependencyId(_In_ PCWSTR what, wil::unique_ptr<WCHAR[]>& packageDependencyId);
HRESULT AddToPackageGraph(_In_ PCWSTR what, _In_ PCWSTR packageDependencyId, INT32 rank);

HRESULT UpdatePackageGraph()
{
    wil::unique_ptr<WCHAR[]> muffinsPackageDependencyId;
    RETURN_IF_FAILED(LoadPackageDependencyId(L"muffins", muffinsPackageDependencyId));
    const INT32 muffinsRank = -42;
    RETURN_IF_FAILED(AddToPackageGraph(muffinsPackageDependencyId.get(), muffinsRank));

    wil::unique_ptr<WCHAR[]> wafflesPackageDependencyId;
    RETURN_IF_FAILED(LoadPackageDependencyId(L"waffles", wafflesPackageDependencyId));
    const INT32 wafflesRank = 3000;
    RETURN_IF_FAILED(AddToPackageGraph(wafflesPackageDependencyId.get(), wafflesRank));

    return S_OK;
}

HRESULT AddToPackageGraph(_In_ PCWSTR what, _In_ PCWSTR packageDependencyId, INT32 rank)
{
    const auto options = MddAddPackageDependencyOptions::None;
    MDD_PACKAGEDEPENDENCY_CONTEXT packageDependencyContext = nullptr;
    wil::unique_process_heap_string packageFullName;
    RETURN_IF_FAILED(MddAddPackageDependency(
        packageDependencyId, rank, options, &packageDependencyContext, &packageFullName));
    wprintf(L"%ls resolved to %ls", what, packageFullName.get());

    return S_OK;
}

HRESULT LoadPackageDependencyId(_In_ PCWSTR what, wil::unique_ptr<WCHAR[]>& packageDependencyId)
{
    // Load the previously stored package dependency identifier
}

WinRT

using Microsoft.Windows.ApplicationModel.DynamicDependency;

var g_packageDependencyContexts = new Dictionary<string, PackageDependencyContext>();

namespace LolzKitten
{
    public class Runtime
    {
        public static void UpdatePackageGraph()
        {
            string muffinsPackageDependencyId = LoadPackageDependencyId(L"muffins");
            const int muffinsRank = -42;
            AddToPackageGraph(muffinsPackageDependencyId, muffinsRank);

            string wafflesPackageDependencyId = LoadPackageDependencyId(L"waffles");
            const int wafflesRank = 3000;
            AddToPackageGraph(wafflesPackageDependencyId, wafflesRank);
        }

        public static void AddToPackageGraph(string what, string packageDependencyId, int rank)
        {
            var packageDependency = new PackageDependency.GetFromId(packageDependencyId);

            var options = new AddPackageDependencyOptions(){ Rank = rank };
            PackageDependencyContext packageDependencyContext = packageDependency.Add(options);
            Console.WriteLine($"{what} via {packageDependencyContext.PackageFullName}");

            // Hang onto the PackageDependencyContext until we're done with it. In this case, the life of the process
            g_packageDependencyContexts[what] = packageDependencyContext;
        }

        static string LoadPackageDependencyId(string what)
        {
            // Load the previously stored package dependency identifier
        }
    }
}