Schlagwort: mesh

Thoughts on the Live Services

After meshing for some days now, I took my 8-miles-running-lap today to think about the Live stack as a whole (I love my runs, it’s the only time to think in-depth on some topics). Thus I want to step back away from the bits and bytes for a moment and review the whole Mesh and Live Services thing. So what does it bring for developers and for consumers? What experiences are changing for them? What is it all about in my eyes? Questions, to which I try to find an answer in this blog post.

What is it about

Let’s start with the general pictures again. From a logical view, the Live Services are just one of the building blocks of the Windows Azure Services platform, as shown in our overall present Windows Azure picture…

Windows Azure Overview

Furthermore, the Live Services are providing some core services on the one hand side and a bunch of Mesh Services on the other. That’s shown by the Live Services overview picture…

Live Services Overview

So we got some core services, we got the mesh and services on it and we got applications today, which are using those services: the Windows Live applications, Office Live and Live Mesh as consumer portion of the mesh and taking advantage of the Mesh Services. At the moment, those applications are relatively distinct from each other in the sense of storage, used APIs and information sharing. For example, with Windows Live comes the 25GB SkyDrive, Office Live has its own workspace and with Live Mesh you get 5GB storage today. Those are not interconnected. But there are big things going on!

From the developer’s view, in the current Live Framework CTP you already take advantage of Windows Live functionality. Thus you are able to access your Live contacts and profiles. Furthermore, you can share data from your mesh with your contacts using various roles. In my opinion, Live Mesh will become part of Windows Live on http://windows.live.com, there earning a central stage. In return, perhaps you will be able to access your calendar, mail and other services programmatically through the Live Framework? We’ll see. Bringing all together is desirable in my eyes.

Ok, let’s continue. So what? What are the core conceptions of the Live Services? For me the whole functionality can be broken down into 2 main points:

Connecting

It’s no secret, what the Live Services and especially the Mesh Services are designed for. They bring together devices, applications, data and people, overcoming traditional barriers between them. The container therefore is the Mesh. In fact there is more than one mesh. You got a mesh of your devices, which share common information. On those devices and in the cloud you can have data and applications, which work with this data or on their own (leading us to the terms of data and application mesh). In a next version of Live Mesh you’ll be able to find applications through an application catalogue and install them on your mesh. Integrating Windows Live applications this way would be nice and I’m interested to see if this will happen soon. And with your contacts you have a mesh of people, with whom you can share your information, your data and even applications.

Thus, connecting means connecting your devices, your data and your applications, but what it really is about and what we can’t see today in Live Mesh (ok, we can see a little of it, but this is only the tip of the iceberg) is the non-egocentric perspective. It’s all about community! About sharing your photos, videos, thoughts and knowledge with your friends and like-minded people. The Live Services foundation is all about this aspect of bringing people together and making „community“ easier and more fun. In the end, it’s bringing YOU with your data/applications/devices/thoughts together with the OTHERS in a way, that doesn’t limit you (in contrast to today’s Web 2.0 platforms, which are bound on one or only a few aspects… or are you using one platform that enables you to organize your digital life with all little aspects through rich applications you wrote or which have been written and shared by others?). For me, Live Services in combination with Mesh are not only services. For me it’s a platform for a huge set of new applications, new business models (putting your favorite ad-engine into your apps is not far away!) and a new way to build up your digital life, using your mesh and the applications that fit your needs. Don’t believe me? I didn’t think so, before I got my iPod Touch (Azure on my head 😉 ) and thousands of apps through the AppStore. Small, cute applications and there is no mesh and no community aspect and no sharing over devices behind (on most). But it makes fun and costs are small. Now I’m mapping this to Silverlight, Mesh, the Live Services and the application catalogue and I see a huge potential!

Synchronizing

The second big functionality aspect when talking about Mesh and the services that come with it is synchronization. This can easily be underestimated, but it implies so much. At first, let me explain this point. As consumer, you currently have the Live Mesh application built onto the Live Services stack. You are able to create folders on your Live Desktop in the cloud and share those folders over your devices. The data is automatically hold in-sync over those devices through the Live Mesh client, which looks for changes and in case of change synchronizes data in the background. That is what you see now.

What you will see in the future, when the application catalogue and applications in your Mesh have come to life: not just data, but the applications in your Mesh will be synchronized to your devices! Thus you not only have your data everywhere, but also the apps, which work with the data, including configuration settings etc.. This leads to offline-scenarios for your mesh applications, if those are relying on data in your mesh (I don’t know if it’s planned to synchronize data of your contacts as well and there are imho some issues with that… we’ll see…). That means you can work offline with your applications and if you come online again, you’ll instantly have your data spread around your devices. I’m agog if there will be an offline-capable version of Windows Live Writer, with which you will be able to write your blog posts offline and then it publishes/synchronizes automatically, when you come online. This would need more integration of Windows Live, but as stated above, this is not far away. Ok, this offline-capability is nice, if you want to do some work where you don’t have Internet (for example in an airplane (standard-example through the PDC and later on ^^), in the train or for me at my parents, because they don’t have Internet (well, they are in fact in stone age and eating with fingers and drawing with chalk on stones etc. … sorry, I’m just joking 😉 )). But while Internet access is widely spread, this has not a heavy impact compared with the synchronization (and everywhere/everytime access for you) itself.

Instead, speed of Internet connection is a important point. For loading big chunks of information from your mesh you need a high-speed connection and even in this case you often have to wait some time, before your data is ready to work with. This drops in case you are working with your mesh data. This data is kept in sync with your computer and thereby you are able to work on your local copy of that data, leading you to instantly accessing that data without downloading it before. If you change the data, the Live Operating Environment (LOE) on your local device notifies these changes and automatically performs the synchronization process to other instances of the LOE (other devices and/or cloud).

Automatic synchronization makes a big difference for the developer, too. Instead of worrying about it, he can rely on this functionality. He can connect to the local LOE and work with the published resources. He doesn’t have to worry about network connections, data retrieval or synchronization – the Live Services are dealing with that. This makes a real difference! Let’s get Azure in mind: the developer can concentrate on the core functionality of his application, thus saving time or spending it to have fun and inspiration while realizing his ideas. Attracting the developer community is in my mind the cornerstone for the success of the Live Services.

What are the benefits

After making clear the core functionality of the Live Services, I want to emphasize (from my point of view) the benefits for consumers as well as for developers, who are programming against the Live Framework.

Consumers

  • Removing barriers: The interface barriers between your devices, data, applications and the people/contacts around you are removed. Thus you are able to interact with those from a central point.
  • Synchronizing: Data and applications everytime and everywhere on your devices! That is what synchronization with your mesh is about. Instead of just synchronizing data, you have the ability to synchronize your mesh applications as well.
  • Offline scenarios: While synchronization of applications is enabled, you can work offline with your applications (in your mesh or only mesh-enabled) which rely on data in your mesh. Instantly when you come online again, the changes will be synchronized automatically to your mesh in the background.
  • Community: Interacting with people, sharing data and taking care of your friends and contacts is made easy with Live Services and Mesh. Have access to your contacts, manage your online profiles and share information, knowledge, multimedia contents and general data as well as applications with your friends, granting them specific rights on your mesh objects. Furthermore, this brings collaboration to life.
  • Applications: Have access to many little applications through your mesh and the central application catalogue. Create instances of those applications on your mesh, synchronize these apps to your machine’s desktops or share them with friends.
  • Manage your digital life: With your data in the mesh and on all of your devices and with applications working on your mesh data, you are able to manage your digital life from a central point. Install applications that fit your needs for every purpose you want and have those applications working on all of your devices. Use services from Windows Live as well and share your life with your friends and families.

Developers

  • Easy programming: Programming with the Live Framework is made easy. You can access your data through central collections and don’t have to worry about common challenging programming tasks. You can query your data resources consistently and have the ability to use LINQ in the .NET libraries. CRUD processes on your data are no problem through a consistent resource model.
  • Consistent access: The Live Framework allows you to consistently access your mesh data, your profiles, contacts and later on other Windows Live services and Live entities with associated relationships.
  • Focusing: Many difficult tasks like network access, authentication, community connection and synchronization are abstracted by the Live Services, Live Framework as programming interface and the Live Operating Environment as a device endpoint for your mesh. Thereby you are able to focus your attention on the important things and the consumer experience of your application.
  • Cloud/client symmetric programming model: It doesn’t matter, which instance of the Live Operating Environment you are accessing. Whether it’s in the cloud or on somebody’s device – you will be able to code against it in a consistent way, thus allowing you easily to realize scenarios of your choice.
  • Business model: You’ll be able to include your favorite ad-engine in your apps to make money with your applications, as those are spread throughout the community.
  • Open access: Access to every instance of the Live Operating Environment (single devices or the cloud) and therefore to your mesh is possible with the programming language and operating system of your choice using a RESTful HTTP interface, that relies on open specifications. You can choose your favorite wire format, too (POX, ATOM, RSS, JSON), because data in the Live Framework is entity/collection-based, has no associated behavior and thereby can easily be transformed into an feed-based model. Furthermore, libraries for many languages will not be far away…
  • Scripting: The Live Operating Environment comes with the ability to compile and run so-called resource scripts. Those are similar to stored procedures in the database world. You can run a resource script on your own or let it run as trigger on data manipulation processes.
  • Mesh-enabling: No matter, if you build up a new application or extend an existing one: making use of mesh-functionality (thus mesh-enabling an application) is no problem and can easily be done with existing libraries.

CTP limitations

While the potential of the Live Services and Live Framework is big in my eyes, there are some limitations with the current Live Framework CTP, which will hopefully be solved in coming releases. The first came up with the installation of the Live Framework client, that is responsible for background synchronization of your mesh objects. At first it was not possible to install the Live Framework client in parallel to an existing Live Mesh client installation. I worked out a solution for that which works well for me, but I don’t know if there are some issues with that. The fact that there’s a separate mesh for the Live Framework instead of using the consumer mesh is a limitation as well, because you cannot access the same data as in your „productive“ mesh.

Another limitation comes with the functionality of the Live Framework client. At the moment, data synchronization is not possible, which means that files and folders from your mesh are not synchronized with devices running the Live Framework client. The same is true for your profiles and contacts, meaning that you have to connect to the cloud LOE to get access for those. Other limitations are, that you can’t get information about the status of a device and no remote access is possible (but this doesn’t count too much).

When programming against the Live Framework CTP, you are currently not able to traverse hierarchical data directly, thus you have to implement it on your own. Further „comfort functionality“ when accessing media resources is missing, too, but that’s no big deal.

Overall, with Live Services, Mesh, Windows Live and the Live Framework the fundamental stones are set for a new platform of rich applications and experiences for both consumers and developers. We’ll see how the community is reacting on this and where the whole thing will be in two years. Until then: what do YOU think?

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Live Framework CTP #5 – .NET: Data hierarchies and LiveItem types

Hierarchies of data entries – the problem

As stated before, when programming against the Live Framework libraries in .NET, all data entries are located on one level below the according data feed. This very often doesn’t correspond with a programmer’s expectations, when he has a hierarchy of data entries, e.g. a hierarchy of data folders and files. As programmer you want to have a tree-like view on this data to work with it. Unfortunately, in the current LiveFx CTP this was not made possible directly.

Extending DataFeed and DataEntry

The solution for this is not far away. A data entry’s resource has got an Id and a ParentId as properties, over which one can identify and associate an entry’s parent and its child entries. A „root entry“ has got the ParentId "urn:uuid:00000000-0000-0000-0000-000000000000" or it is null. This information is sufficient to write some extension methods on DataFeed and DataEntry for getting hierarchical information. Thus I’m starting to make a little class library, which I will further work on and extend it. First I’ve got a little class named „MeshConstants„. There resides the ParentId for a root data entry:

public static class MeshConstants
{
    public const string RootDataEntryId = "urn:uuid:00000000-0000-0000-0000-000000000000";
}

With this it’s easy to extend DataFeed with a method GetRootDataEntries(), which delivers only the data entries on the top level of the hierarchy:

public static ICollection<DataEntry> GetRootDataEntries(this DataFeed feed)
{
    return (from entry in feed.DataEntries.Entries
            where entry.IsLoaded && entry.IsRootEntry()
            select entry).ToList();
}

This method accesses IsRootEntry() of DataEntry, which is an extension method, too and indicates, if a data entry is on the root level (has no parent) or not:

public static bool IsRootEntry(this DataEntry entry)
{
    if (String.IsNullOrEmpty(entry.Resource.ParentId))
        return true;

    return entry.Resource.ParentId.Equals(MeshConstants.RootDataEntryId);
}

Another extension method for DataEntry gives us the child entries in return:

public static ICollection<DataEntry> GetChildEntries(this DataEntry entry)
{
    return (from child in entry.GetDataFeed().DataEntries.Entries
            where child.Resource.ParentId == entry.Resource.Id
            select child).ToList();
}

This makes use of the method GetDataFeed(), which is needed for getting the data feed, this data entry is associated to. Unfortunately, the .NET libraries of the Live Framework CTP don’t come along with this possibility innately:

public static DataFeed GetDataFeed(this DataEntry entry)
{
    return (from feed in
                (from meshobj in entry.LiveOperatingEnvironment.Mesh.MeshObjects.Entries
                 select meshobj.DataFeeds.Entries).Aggregate((fl1, fl2) => fl1.Union(fl2))
                 where feed.DataEntries.Entries.Contains(entry)
            select feed).Single();
}

Example: traversing the hierarchy

Now we’ve got all together for traversing a hierarchy of data entries recursively. We just need a recursive method, which executes the wanted action for a data entry and then recursively calls itself for all child entries. The following example method builds up a WinForms TreeView structure by adding TreeNode elements recursively:

private void addTreeNodesForChildDataEntries(DataEntry parentEntry, TreeNode parentNode)
{
    foreach (var childEntry in parentEntry.GetChildEntries())
    {
        var childNode = new TreeNode(childEntry.Resource.Title + ": " + childEntry.Resource.Type);
        parentNode.Nodes.Add(childNode);
        addTreeNodesForChildDataEntries(childEntry, childNode);
    }
}

The result is shown below exemplarily:

Live Framework - Recursing TreeView example

Types of LiveItem elements

The resources of MeshObject, DataFeed and DataEntry have an associated Type property, over which you can distinguish different types of objects. Furthermore, Type is a string and thus allows you to define your own application-specific object types. But the Live Framework comes with some standard types by default, where the most important are:

MeshObject.Type:

  • "LiveMeshFolder": Top-level folder, which can contain further (data entry) folders and files.
  • "ApplicationInstance": Instance of an application, which has been installed through the Live Application Catalogue.

DataFeed.Type:

  • "LiveMeshFiles": Indicates the feed as container for file and folder data entries.

DataEntry.Type:

  • "Folder": Data entry is a folder, which can contain further data entries.
  • "File": Data entry is a file, which may contain your data.

Based on that information (and the extension methods above), I’ve written some more extension methods on the several classes to filter the child elements accordingly:

public static class MeshObjectTypes
{
    public const string LiveMeshFolder = "LiveMeshFolder";
    public const string ApplicationInstance = "ApplicationInstance";
}

public static class DataFeedTypes
{
    public const string LiveMeshFiles = "LiveMeshFiles";
}

public static class DataEntryTypes
{
    public static string File = "File";
    public static string Folder = "Folder";
}

public static class MeshExtensions
{
    public static ICollection<MeshObject> GetApplicationInstanceMeshObjects(this Mesh mesh)
    {
        return (from meshobj in mesh.MeshObjects.Entries
                where meshobj.Resource.Type == MeshObjectTypes.ApplicationInstance
                select meshobj).ToList();
    }

    public static ICollection<MeshObject> GetFolderMeshObjects(this Mesh mesh)
    {
        return (from meshobj in mesh.MeshObjects.Entries
                where meshobj.Resource.Type == MeshObjectTypes.LiveMeshFolder
                select meshobj).ToList();
    }
}

public static class MeshObjectExtensions
{
    public static ICollection<DataFeed> GetFilesChildFeeds(this MeshObject meshobj)
    {
        return (from feed in meshobj.DataFeeds.Entries
                where feed.Resource.Type == DataFeedTypes.LiveMeshFiles
                select feed).ToList();
    }
}

public static class DataFeedExtensions
{
    public static ICollection<DataEntry> GetFileDataEntries(this DataFeed feed)
    {
        return feed.GetFileDataEntries(false);
    }

    public static ICollection<DataEntry> GetFolderDataEntries(this DataFeed feed)
    {
        return feed.GetFolderDataEntries(false);
    }

    public static ICollection<DataEntry> GetFileDataEntries(this DataFeed feed, bool onlyRootEntries)
    {
        var entries = onlyRootEntries ? feed.GetRootDataEntries() : feed.DataEntries.Entries;
        return (from entry in entries
                where entry.Resource.Type == DataEntryTypes.File
                select entry).ToList();
    }

    public static ICollection<DataEntry> GetFolderDataEntries(this DataFeed feed, bool onlyRootEntries)
    {
        var entries = onlyRootEntries ? feed.GetRootDataEntries() : feed.DataEntries.Entries;
        return (from entry in entries
                where entry.Resource.Type == DataEntryTypes.Folder
                select entry).ToList();
    }
}

public static class DataEntryExtensions
{
    public static ICollection<DataEntry> GetFileChildEntries(this DataEntry entry)
    {
        return (from child in entry.GetChildEntries()
                where child.Resource.Type == DataEntryTypes.File
                select child).ToList();
    }

    public static ICollection<DataEntry> GetFolderChildEntries(this DataEntry entry)
    {
        return (from child in entry.GetChildEntries()
                where child.Resource.Type == DataEntryTypes.Folder
                select child).ToList();
    }
}

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