Mobile App Development: Creating A Qr Code Reader In The Mobile Website Version!

By Author: Ash Rakars
Total Articles: 308
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Do you know, that in 2016, the number of online or digital shoppers globally was around 1.66 billion and is expected to reach 2.14 billion in 2021? These numbers are significantly increasing year after year. Businesses have taken note of these statistics. They have realized the importance of making the payment functionality simpler for the users. The introduction of the Barcode and QR scanners was one such effort. It has made shopping experience much flexible and hassle-free. Even giants like Amazon and Walmart have embraced this amazing feature in their apps.

So, if you too want to ensure that your users get rid of typing the long activation codes, save from the frustration of fidgeting with mini keyboards or cross-checking the codes for errors multiple times, and also make the payments instantly consider integrating the barcode reader functionality in your mobile app development services. Let’s get started with the procedure.

Employing QR Code Scanning Feature in Your Mobile ...
... Website

Firstly, create a QR code reader of your own by running a bit of JavaScript code on your website on the smartphone that has a camera. If not possible, get a sample QR code temporarily for this assignment.

Developing a QR Code Reader

Creating this QR code reader needs HTML, JavaScript along with a JavaScript library that comes with capabilities to interpret the QR code. We will create this from freely available libraries and not create it ourselves.

Now, first, create an index.html file.

Adding the Required HTML tag and some Styles

Add the appropriate HTML code to the body tag. You will see a wrapper container with some title, a canvas, a QR icon image in ‘a’ tag, and a “div” where the results of the scan will be visible.

Now for adding styles, add the designed style-sheet in the heading section of the HTML code. Next, add the CSS file for creating the style.css file in the “src” folder. There will be a big QR button present in the middle with a simple design of the app.

Adding the Dependent JS Libraries

Here we will be using an open-source JavaScript library for reading QR codes. Written by ZXing, it is a Java-based image processing library. This library comprises 17 files which we need to merge into one file. For preventing the pollution of the global namespace, we need to wrap the code in an anonymous function. And then, for making the file size smaller put the file through Google Closure’s minifier.

Minor Modifications in the JS Library

We need to do some modifications to the output function of the library to make it more adaptable. This helps to differentiate between an error response and a success response. For this, make the appropriate changes in the “qrcode.js” with the right code, so that the strings will be replaced by “error” objects.

Now, the mobile app developers can check and understand if the call-back payload from the callback function is the instance of the Error or not and thus, find out if an error occurred.

Employing the Script Tag

For using this library in the QR code reader, first, the mobile app developers need to consider it in the HTML code by implementing a regular script tag.

Treating It as a Mobile Application

The developers will have to make some modifications for telling the mobile browsers that there isn’t a need to scale this website in portrait mode. For this, they should add the apt meta-tag in the head element.

Writing the JavaScript Code

In the src folder, we need to develop the “qrCodeReader.js” file which should be at the level of HTML file. So, add the required code to the new file. Above this code, the “qrcode” object is available from window, which we need to assign to a constant. Then, build a video element that will be required for handling images from the camera.

After this, we use the canvas element for assigning the 2d context to a constant; it will be required for drawing images that come from the camera.

Next, we have some relevant elements for interacting with the app and specifying the results. So, for keeping the scanner’s status, declare scanning variable.

Then add the right code to the file’s bottom to set the callback for the QR code reader.

There are a few more things we need to ensure to handle the scanner response. Firstly, set the scanning variable to false, then, ensure that the streaming from the user’s camera is stopped. Then ensure that results are visible to users and they can trigger further scans.

Next, access the camera feed for setting up a loop and drawing the required images in the canvas.

We need to handle scanning the frames in a different loop altogether. This can be done in the “onclick” handler present in the element- “btnScanQR”.

For playing the videos, draw the steam for each frame and call the tick function using the right code.

Lastly, we should define the scan function. Now let’s test the app.

QR Code Reader Functioning in the Website Mobile App

Now, you are done with the complete procedure and it’s time to see the QR Reader in action. Tap on the QR button and place some QR code in front of the camera for scanning. Hold it there for some time and done. Your QR code scanner is ready to be used.

Final Words:

So this was the detailed procedure to get a QR code scanner embedded in your app. It is a dynamic functionality that can be used from any platform and helps to make your mobile app greatly useful to the targeted users.

So, if you are willing to get this amazing feature of QR code reader integrated into your mobile app, hire expert mobile app developers from Biz4Solutions. Biz4Solutions is an eminent mobile app development company delivering cutting-edge software solutions to its global client base for more than 9 years. For any further assistance, drop us the details at sales.enquiry@biz4solutions.com.

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