Easy programmatic access to the file system, file type associations, and new system UI controls for...

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APP-398T

How to declare your app’s capabilities

Jeff JohnsonDirector of DevelopmentWindows User ExperienceMicrosoft Corporation

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Agenda

• Explore the capability model for Metro style apps• Best practices for accessing the file system and

devices• New features for working with capabilities

You’ll leave with examples of how to• Identify and add any required capabilities• Incorporate programmatic file access in your app

Capabilities provide access to system resources and connected devices, and are declared in the

package manifest.

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Capabilities enable…

• Easy programmatic access to the file system, file type associations, and new system UI controls for opening files

• Simple integration with the file system and connected devices like webcams and location sensors

• New declarative access model for PC resources that shows users app capabilities prior to purchase

Capabilities in the Store

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• Users are notified about which capabilities an app declares as part of their app Store acquisition • Ensure that requested capabilities match customer

expectations

• Users can also easily enable or disable access to sensitive devices via the Settings Charm for each app

• File type associations are also declarative, and users can select their preferred applications for each file type

Keeping the user in control

Suspect capabilities

This app could use your:LocationDocuments LibraryWebcamMicrophone

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Invocation & Contracts

Windows Runtime environment

AppContainer – Signed + Validated

process.exe

WinRT

APIs

Core OS

Direct API calls

Filtered to declared capabilities in the package manifest

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Metro style app packages

• A package contains each Metro style app

• Delivered by a single trusted store

• Easy for users to install and uninstall

• Explicitly declares the app interface points used• Capabilities• Devices• File type associations• App contracts

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File capabilities

• musicLibrary• picturesLibrary• videoLibrary• documentsLibrary• removableStorage

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Device capabilities

• webcam• microphone• location• sms• proximity• extensible to new device classes…

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Network & identity capabilities

• Network capabilities• internetClient• internetClientServer• privateNetworkClientServer

• Identity capabilities• defaultWindowsCredentials• sharedUserCertificates

Manifest Designer

Example: capabilities XML

<Capabilities> <Capability Name="picturesLibrary" /> <Capability Name="internetClient" /></Capabilities>

Packages without capabilities still have access to private working

folders, and simple sensors such as accelerometers.

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Accessing the file system via the file picker

demo

Opening multiple items

// JavaScriptvar picker = new Windows.Storage.Pickers.FileOpenPicker();

picker.fileTypeFilter.replaceAll(["*"]);

picker.pickMultipleFilesAsync().then(function (files) { if (files.size > 0) { // Manipulate array of picked file(s) } else { // No files were returned. }}); 

// C#FileOpenPicker picker = new Windows.Storage.Pickers.FileOpenPicker();

picker.fileTypeFilter.replaceAll(["*"]);

IReadOnlyList<StorageFile> files = await openPicker.PickMultipleFilesAsync();if (files.Count > 0) { // Manipulate array of picked file(s)} else { // No files were returned. }

Saving a file (JavaScript)// JavaScriptvar savePicker = new Windows.Storage.Pickers.FileSavePicker();savePicker.defaultFileExtension = ".docx";savePicker.suggestedFileName = "New Document";savePicker.fileTypeChoices.insert("Microsoft Word Document", [".docx", ".doc"]);savePicker.fileTypeChoices.insert("Plain Text", [".txt"]);

savePicker.pickSaveFileAsync().then( function (file) { if (file) { // Application now has read/write access to the saved file } else { // A file was not returned (cancelled, access denied, etc.) } });

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Picker properties

• Presentation mode• thumbnail, list

• Default location• Individual user libraries or computer

• Custom button labels • Open, Save, Import, Upload, etc.

• Picker Identifier• Allows multiple picker contexts within an app

Programmatic access to files and folders

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Programmatic access to the Pictures Library

demo

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Documents Library & removable storage

• Access to the documents library and removable storage is filtered to file type associations in your package manifest.

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Accessing the Documents Library

demo

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File type associations

• Registration via manifest• File type associations are statically declared in the

manifest.• Users receive a toast if your app can open a previously

registered file type. • Launch events are handled as part of application

activation.// Receive activation.function onActivatedHandler(eventArgs) { if (eventArgs.kind == Windows.ApplicationModel.Activation.ActivationKind.file) { // ...

Device capabilities

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Using devices

• Simple integration with native and specialized devices

• Declarative access model for common device classes • Webcam and microphone• Location • Proximity• SMS• And others…

• User consent model for sensitive device classes

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How to handle absence of a device?

• Developers should handle the absence of a device because• The device may not always be present or operational• The user can disable access in the app

• Defer access to devices until absolutely needed

• Plan for secondary experiences when a device is not available

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Consent prompt and granting/disabling access (location)

demo

Recap

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Recap

• Declare the capabilities you need

• Request only the capabilities you need

• Defer using devices until they are actually needed

• Build great experiences that respect customer decisions

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Related sessions

• [PLAT-282T] File type associations and AutoPlay• [HW-745T] Reimagining the experience for connecting with

devices• [HW-747T] Building Metro style apps that connect to

specialized devices • [PLAT-785T] Creating connected apps that just work on

today's networks • [PLAT-894T] Seamlessly interacting with web and local data

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Further reading and documentation

• File SDK samples• File access• File picker• Folder enumeration

• Device SDK samples• Geolocation• Media capture

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• Feedback and questions http://forums.dev.windows.com

• Session feedbackhttp://bldw.in/SessionFeedback

thank you

© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to

be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.