Accessing devices and sensors - Build Windows 8 Apps with HTML5 and JavaScript - page 293

<br />
<button id="buttonShoot" class="horizontalBtn">Take a picture</button>
<br />
</div>
Basically, the webcam application consists of a button that triggers the webcam and an IMG
element where users will view the captured image. The final preliminary step is to add a handler for
the click event for the Take A Picture button. Open the instantPhotoApp.js file and type the following
code:
instantPhotoApp.init = function () {
document.getElementById("buttonShoot")
.addEventListener("click", instantPhotoApp.takePicture);
};
instantPhotoApp.takePicture = function () {
// Some more code here
}
Now, you're all set and ready to tackle the webcam API.
Checking the webcam capability
Code is not allowed to freely access the webcam without explicit user permission. For this reason, to
give your app a chance to successfully use the webcam you must first declare your intention to use it.
As shown in Figure 12-1, double-click the manifest file you have in the project and select the
Capabilities tab from the subsequent view.
FIGURE 12-1 Enabling the capability that gives your code the ability to access the webcam programmatically.