Click here to close now.

Welcome!

Industrial IoT Authors: Pat Romanski, Liz McMillan, Elizabeth White, Carmen Gonzalez, AppDynamics Blog

Blog Feed Post

How to: Use the SharePoint 2013 REST API from a Windows Store App (Windows 8 Metro)

I’ve recently taken an interest to building Windows Store Apps (aka Windows 8 Metro).  Not because I think I can get rich in the Windows Store but because I think it provides a unique way to present SharePoint data.  If you’re like me, you probably assumed Windows Store App development was just like .NET Framework 4.5 development.  You would be wrong.  The .NET Framework is provided by a single assembly reference called .NET for Windows Store Apps.  It has many of the familiar classes that you have come to expect.  My initial thinking was that I could use the SharePoint Client Object Model directly from my app.  That thinking was also wrong.  It turns out that the Client Object Model has a dependency on System.Web.Service.dll which does not exist in .NET for Windows Store Apps.  Simply put, Window Store Apps only support WCF references.  This means that the REST API is now our best choice.

When it comes to Windows Store Apps, you have a few choices on which programming language to use.  Modern JavaScript is not my strong point, so I am going to demonstrate using C#.  Before we dig into the C# code though, we’ll take a look at how to construct the REST URL.  This article on MSDN does a great job explaining the details of how the URL is built.  Essentially we start with the URL to our site (i.e.: http://server/site) and append /_api/web/lists to it along with a method to get a particular list by title, getbytitle.  To get the items of the list we append /items to it.   In my case, I want to pull the tasks list of a site so it would look something like this.

http://server/site/_api/web/list/getbytitle(‘tasks’)/items

You can type this right into your browser and see the XML that the REST API returns.  Here’s an example.

RESTAPIListsBrowser

There is a lot of XML to take in there.  We’re particularly interested in the content element contain in each entry element.  This has the data from our list items.  However, we can reduce the amount of XML returned significantly by using the $select parameter on the REST URL.  In my case I am going to select a few common fields such as Title, DueDate, and Status.  Here is what the URL looks like now.

http://server/site/_api/web/list/getbytitle(‘tasks’)/items?$select=Title,DueDate,Status,PercentComplete

RESTAPIListsWithSelectBrowser

You’ll notice that the results are much more manageable now.  We’ll talk about how we can use LINQ to XML here shortly to parse this data into something usable from our Windows Store app. 

Now let’s look at the code that is required to get the data in our app.  Start by creating a new Windows Store App in Visual Studio 2012.  You can do this by choosing your language (C#) and then Windows Store –> Blank App (XAML).

VS12NewWindowsStoreApp

If this is the first Windows Store App you have started in Visual Studio, you will be prompted for your Windows Live credentials.  This allows you to get a certificate so that you can build apps locally.  In our app, we want to bind data, so I am going to create a new Items Page.  This template has many of the components you need to get started quickly with data binding.

VS12NewItemsPage

When adding the page, you will be prompted to add some dependent files.  Click yes and then you should see your design surface.  Now, open the code-behind of your Items page.  In the LoadState method, we will start the process of retrieving our data and binding it.  We rely on some asynchronous calls to get data from REST, so we will need to put this data in another method and use the async keyword.

protected override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)

{

    // TODO: Assign a bindable collection of items to this.DefaultViewModel["Items"]

    BindData();

}

 

private async void BindData()

{

 

}

Before we start writing the method though, we need to include a few using statements.

using System.Net;

using System.Net.Http;

using System.Xml;

using System.Xml.Linq;

If you have looked at any of the other C# examples for working with the REST API, you will know they are heavily dependent on the HttpWebRequest object.  However, with Windows Store Apps, we have to use HttpClient instead. We’ll start by defining our REST URL from up above.

string restUrl = "http://server/_api/lists/getbytitle('tasks')/items?$select=Title,DueDate,Body,Status,PercentComplete";

To handle authentication we first need to create an HttpClientHandler object.  We want to automatically use the credentials of the currently logged in user so this is required.  To enable this, just set UseDefaultCredentials to true.  There are also other settings required which we’ll talk about below.

HttpClientHandler httpClientHandler = new HttpClientHandler();

httpClientHandler.UseDefaultCredentials = true;

We can now create the HttpClient object by passing the HttpClientHandler to the constructor.

HttpClient client = new HttpClient(httpClientHandler);

We then need to tell the REST API, that we want the result back as ATOM / XML as opposed to JSON.  We do this by setting a few headers.

client.DefaultRequestHeaders.Add("Accept", "application/atom+xml");

client.DefaultRequestHeaders.Add("ContentType", "application/atom+xml;type=entry");

Now, we can send the request to SharePoint and wait for a response.  We use the await keyword on the GetAsync() method which is why we needed the async keyword on the method signature.  The EnsureSuccessStatusCode() method simply throws an exception if a valid 200 HTTP response is not received.

var response = await client.GetAsync(restUrl);

response.EnsureSuccessStatusCode();

At this point our data has been received back at the client from SharePoint.  Now we need to begin the fun process of parsing it and binding it.  We get the raw string XML data with the following method (also asynchronous).  You could run the app at this point (with a few tweaks) if you wanted to see it in the debugger but we haven’t done anything wit the data yet.

string

responseBody = await response.Content.ReadAsStringAsync();

Now we need to read the XML into an XDocument object so that we can use LINQ to XML to parse it.

StringReader reader = new StringReader(responseBody);

XDocument responseXml = XDocument.Load(reader, LoadOptions.None);

Now we have the data into something queryable.  However, what we really need is a custom object that we can bind to.  If you look back at the XML, you might have noticed a few namespaces in use in the XML document.  We need to define those or our queries will never work.

XNamespace atom = "http://www.w3.org/2005/Atom";

XNamespace d = "http://schemas.microsoft.com/ado/2007/08/dataservices";

XNamespace m = "http://schemas.microsoft.com/ado/2007/08/dataservices/metadata";

Now, we can use LINQ to XML to select the data into a new anonymous type.  If you look at the XML again, we want to query entry elements using the Descendants() method and then the actual values we want are inside the nested Content and then Properties elements.  The data is heavily nested so it makes our LINQ to XML a little messy.  It’s not too bad though.  For the non-string values, I parse the data into the type that I want it (i.e.: DateTime).

var items = from item in responseXml.Descendants(atom + "entry")

            select new

            {

                Title = item.Element(atom + "content").Element(m + "properties").Element(d + "Title").Value,

                DueDate = DateTime.Parse(item.Element(atom + "content").Element(m + "properties").Element(d + "DueDate").Value),

                Status = item.Element(atom + "content").Element(m + "properties").Element(d + "Status").Value,

                PercentComplete = decimal.Parse(item.Element(atom + "content").Element(m + "properties").Element(d + "PercentComplete").Value)

            };

Now, we have data that can be bound to the GridView / ListView on the Items Page.  To bind we assign our data source as follows:

this

.DefaultViewModel["Items"] = items;

Just like Windows Phone and SharePoint apps need to declare the capabilities of the application, Windows Store Apps are no different.  To do this, open Package.appmanifest.  In our case, we need to declare that we intend to communicate over the internal network (Private Networks) and that we need Enterprise Authentication.  The latter allows the app to authenticate with the current user’s domain credentials automatically.  If you don’t have this capability set, you are guaranteed a 401 Access Denied or Unable to connect to remote server error.

Windows8ProjectCapabilities

We can now run the app.  However, there is one last thing we need to do.  We need a way to navigate to the TaskItemsPage that we created.  It loads MainPage by default.  Without getting to deep into how Windows Store app navigation works, we’ll just throw a button on the MainPage and then navigate to the TaskItemsPage when clicked.  You can drag and drop a button onto the MainPage using the designer.  Double click on it and it will create the event handling method.  Then we use Frame.Navigate() and pass it the type of page we want to go to, TaskItemsPage.  Here is the code.

private void Button_Click_1(object sender, RoutedEventArgs e)

{

    Frame.Navigate(typeof(TasksItemsPage));

}

Run your app, and click on the button to navigate to your TaskItemsPage.  If all goes well, you won’t receive any errors and you’ll see a page like the screen below.  Note, that your application doesn’t currently have any way to exit.  To get out you either need to Alt+Tab or move your mouse to the Top-Left corner of the screen to switch to the desktop.

Windows8TasksItemsPage

This is great, but we’re not using all of our data yet.  By default, it will bind the Title for us.  However, we want to display some of our additional fields though.  To do this, we can create a DataTemplate.  We need to look into how it works first though.  Locate the GridView in your XAML file.  It should look something like this.

<GridView

    x:Name="itemGridView"

    AutomationProperties.AutomationId="ItemsGridView"

    AutomationProperties.Name="Items"

    TabIndex="1"

    Grid.RowSpan="2"

    Padding="116,136,116,46"

    ItemsSource="{Binding Source={StaticResource itemsViewSource}}"

    ItemTemplate="{StaticResource Standard250x250ItemTemplate}"

    SelectionMode="None"

    IsSwipeEnabled="false"/>

Notice the ItemTemplate and how it is bound to Standard250x250ItemTemplate.  This template can actually be found in StandardStyles.xaml

<DataTemplate x:Key="Standard250x250ItemTemplate">

    <Grid HorizontalAlignment="Left" Width="250" Height="250">

        <Border Background="{StaticResource ListViewItemPlaceholderBackgroundThemeBrush}">

            <Image Source="{Binding Image}" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>

        </Border>

        <StackPanel VerticalAlignment="Bottom" Background="{StaticResource ListViewItemOverlayBackgroundThemeBrush}">

            <TextBlock Text="{Binding Title}" Foreground="{StaticResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextStyle}" Height="60" Margin="15,0,15,0"/>

            <TextBlock Text="{Binding Subtitle}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>

        </StackPanel>

    </Grid>

</DataTemplate>

If you look at what it is binding, it’s looking for fields Image, Title, and Subtitle.  We don’t have an image, so we can get rid of that.  In its place, we’ll add the other fields in our dataset.  We don’t want to edit the out-of-the-box template, so we can copy this snippet and add it to the Pages.Resources element in our TaskItemsPage.xaml.  I then changed its name to TaskItemTemplate and added the remaining fields.

<DataTemplate x:Key="TaskItemTemplate">

    <Grid HorizontalAlignment="Left" Width="250" Height="250">

        <StackPanel VerticalAlignment="Top" Background="{StaticResource ListViewItemOverlayBackgroundThemeBrush}">

            <TextBlock Text="{Binding Title}" Foreground="{StaticResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextStyle}" Height="60" Margin="15,0,15,0"/>

            <TextBlock Text="{Binding DueDate}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>

            <TextBlock Text="{Binding PercentComplete}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>

            <TextBlock Text="{Binding Status}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>

        </StackPanel>

    </Grid>

</DataTemplate>

Now we just need to change the template name in the GridView to use the TaskItemTemplate.

<GridView

    x:Name="itemGridView"

    AutomationProperties.AutomationId="ItemsGridView"

    AutomationProperties.Name="Items"

    TabIndex="1"

    Grid.RowSpan="2"

    Padding="116,136,116,46"

    ItemsSource="{Binding Source={StaticResource itemsViewSource}}"

    ItemTemplate="{StaticResource TaskItemTemplate}"

    SelectionMode="None"

    IsSwipeEnabled="false"/>

Run the app again and you’ll now have your custom fields bound.  It should look something like this.

Windows8TasksItemsPageCustomTemplate

The DueDate and PercentComplete are not formatted in this case.  I won’t cover that today, but if you look at the Blog Reader example, it explains the techniques you can use to do cool formatting.  The Data Binding article goes into a lot of detail if you want to learn all of the ways you can bind data too.  If you want a good tutorial to start from scratch on a Windows Store App, see the Hello, World example.

This turned out to be quite the long blog post.  I hope you find it useful.  If you find this interesting and you are going to be at SharePoint Conference 2012 in November (SPC12), you should be sure and attend my session Bringing SharePoint to the Desktop: Building Windows Store Apps with SharePoint 2013 (SPC025).

Follow me on twitter @coreyroth.

Read the original blog entry...

More Stories By Corey Roth

Corey Roth, a SharePoint Server MVP, is a consultant at Hitachi Consulting specializing in SharePoint and Office 365 for clients in the energy sector. He has more than ten years of experience delivering solutions in the energy, travel, advertising and consumer electronics verticals.

Corey specializes in delivering ECM and search solutions to clients using SharePoint. Corey has always focused on rapid adoption of new Microsoft technologies including Visual Studio 2013, Office 365, and SharePoint.

He is a member of the .NET Mafia (www.dotnetmafia.com) where he blogs about the latest technology and SharePoint. He is dedicated to the community and speaks regularly at user groups and SharePoint Saturdays.

@ThingsExpo Stories
Connected things, systems and people can provide information to other things, systems and people and initiate actions for each other that result in new service possibilities. By taking a look at the impact of Internet of Things when it transitions to a highly connected services marketplace we can understand how connecting the right “things” and leveraging the right partners can provide enormous impact to your business’ growth and success. In her general session at @ThingsExpo, Esmeralda Swartz, VP, Marketing Enterprise and Cloud at Ericsson, discussed how this exciting emergence of layers of...
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal today!
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Among the proven benefits, DevOps is corr...
SYS-CON Events announced today that kintone has been named “Bronze Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. kintone promotes cloud-based workgroup productivity, transparency and profitability with a seamless collaboration space, build your own business application (BYOA) platform, and workflow automation system.
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo in Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal an...
The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists addressed this very serious issue of profound change in the industry.
Buzzword alert: Microservices and IoT at a DevOps conference? What could possibly go wrong? In this Power Panel at DevOps Summit, moderated by Jason Bloomberg, the leading expert on architecting agility for the enterprise and president of Intellyx, panelists peeled away the buzz and discuss the important architectural principles behind implementing IoT solutions for the enterprise. As remote IoT devices and sensors become increasingly intelligent, they become part of our distributed cloud environment, and we must architect and code accordingly. At the very least, you'll have no problem fillin...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Architect for the Internet of Things and Intelligent Systems, described how to revolutionize your archit...
SYS-CON Events announced today that Secure Infrastructure & Services will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Secure Infrastructure & Services (SIAS) is a managed services provider of cloud computing solutions for the IBM Power Systems market. The company helps mid-market firms built on IBM hardware platforms to deploy new levels of reliable and cost-effective computing and high availability solutions, leveraging the cloud and the benefits of Infrastructure-as-a-Service (IaaS...
In his General Session at 16th Cloud Expo, David Shacochis, host of The Hybrid IT Files podcast and Vice President at CenturyLink, investigated three key trends of the “gigabit economy" though the story of a Fortune 500 communications company in transformation. Narrating how multi-modal hybrid IT, service automation, and agile delivery all intersect, he will cover the role of storytelling and empathy in achieving strategic alignment between the enterprise and its information technology.
SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet conditions, Dyn ensures traffic gets delivered faster, safer, and more reliably than ever.
SYS-CON Events announced today that CommVault has been named “Bronze Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular Information Management® solutions for high-performance data protection, universal availability and simplified management of data on complex storage networks. CommVault's exclusive single-platform architecture gives companies unp...
"We have a tagline - "Power in the API Economy." What that means is everything that is built in applications and connected applications is done through APIs," explained Roberto Medrano, Executive Vice President at Akana, in this SYS-CON.tv interview at 16th Cloud Expo, held June 9-11, 2015, at the Javits Center in New York City.
Internet of Things is moving from being a hype to a reality. Experts estimate that internet connected cars will grow to 152 million, while over 100 million internet connected wireless light bulbs and lamps will be operational by 2020. These and many other intriguing statistics highlight the importance of Internet powered devices and how market penetration is going to multiply many times over in the next few years.
SYS-CON Events announced today that Intelligent Systems Services will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Established in 1994, Intelligent Systems Services Inc. is located near Washington, DC, with representatives and partners nationwide. ISS’s well-established track record is based on the continuous pursuit of excellence in designing, implementing and supporting nationwide clients’ mission-critical systems. ISS has completed many successful projects in Healthcare, Commercial, Manu...
SYS-CON Events announced today that SoftLayer, an IBM company, has been named “Gold Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place November 3–5, 2015 at the Santa Clara Convention Center in Santa Clara, CA. SoftLayer operates a global cloud infrastructure platform built for Internet scale. With a global footprint of data centers and network points of presence, SoftLayer provides infrastructure as a service to leading-edge customers ranging from Web startups to global enterprises. SoftLayer’s modular architecture, full-featured API, and sophisticated automation pro...
The basic integration architecture, as defined by ESBs, hasn’t changed for more than a decade. Most cloud integration providers still rely on an ESB architecture and their proprietary connectors. As a result, enterprise integration projects suffer from constraints of availability and reliability of these connectors that are not re-usable across other integration vendors. However, the rapid adoption of APIs and almost ubiquitous availability of APIs amongst most SaaS and Cloud applications are rapidly redefining traditional integration approaches and their reliance on proprietary connectors. ...
SYS-CON Events announced today that WHOA.com, an ISO 27001 Certified secure cloud computing company, participated as “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which took place June 9-11, 2015, at the Javits Center in New York City, NY. WHOA.com is a leader in next-generation, ISO 27001 Certified secure cloud solutions. WHOA.com offers a comprehensive portfolio of best-in-class cloud services for business including Infrastructure as a Service (IaaS), Secure Cloud Desktop, Cloud Storage, Disaster Recovery, Integrated Applications and Security.
Today air travel is a minefield of delays, hassles and customer disappointment. Airlines struggle to revitalize the experience. GE and M2Mi will demonstrate practical examples of how IoT solutions are helping airlines bring back personalization, reduce trip time and improve reliability. In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect with GE, and Dr. Sarah Cooper, M2Mi’s VP Business Development and Engineering, will explore the IoT cloud-based platform technologies driving this change including privacy controls, data transparency and integration of real time context wi...
17th Cloud Expo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterprises are using some form of XaaS – software, platform, and infrastructure as a service.