dynamsoft-javascript-barcode
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    8.6.1 • Public • Published

    Dynamsoft Barcode Reader for Your Website

    Turn your web page into a barcode scanner with just a few lines of code.

    version downloads jsdelivr

    Once integrated, your users can open your website in a browser, access their cameras and read barcodes directly from the video input.

    In this guide, you will learn step by step on how to integrate this library into your website.

    For back-end barcode reading with Node.js, see Dynamsoft Barcode Reader for Node.

    Table of Contents

    Popular Examples

    You can also:

    Hello World - Simplest Implementation

    Let's start by testing the "Hello World" example of the library which demonstrates how to use the minimum code to enable a web page to read barcodes from a live video stream.

    Step One: Check the code of the example

    The complete code of the "Hello World" example is shown below

    <!DOCTYPE html>
    <html>
    
    <body>
      <script src="https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.6.1/dist/dbr.js"></script>
      <script>
        // initializes and uses the library
        let pScanner = null;
        (async () => {
          let scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
          scanner.onFrameRead = results => {
            if (results.length > 0) console.log(results);
          };
          scanner.onUnduplicatedRead = (txt, result) => {
            alert(txt);
          };
          await scanner.show();
        })();
      </script>
    </body>
    
    </html>

    You can also find the code (with more comments) on GitHub.

    About the code

    • createInstance(): This method creates a BarcodeScanner object. This object can read barcodes directly from a video input with the help of its interactive UI (hidden by default) and the MediaDevices interface.

    • onFrameRead: This event is triggered every time the library finishes scanning a video frame. The results object contains all the barcode results that the library have found on this frame. In this example, we print the results to the browser console.

    • onUnduplicatedRead: This event is triggered when the library finds a new barcode, which is not a duplicate among multiple frames. txt holds the barcode text value while result is an object that holds details of the barcode. In this example, an alert will be displayed for this new barcode.

    • show(): This method brings up the built-in UI of the BarcodeScanner object.

    Step Two: Test the example

    You can choose one of three ways to test the example:

    Either way, you open the example page in a browser, allow the page to access your camera and the video will show up on the page. After that, you can point the camera at something with a barcode to read it.

    If the barcode is decoded, an alert will pop up with the result text. At the same time, the barcode location will be highlighted in the video feed.

    For first use, you may need to wait a few seconds for the library to initialize.

    Note:

    • The library only scans a new frame when it has finished scanning the previous frame. The interval between two consecutive frames might not be enough time for the library to process the 1st frame (for 30 FPS, the interval is about 33 ms), therefore, not all frames are scanned.

    • The library requires a license to work. However, when no license is specified in the code, Dynamsoft allows a 7-day free period during which you can make initial evaluation of the library to decide whether or not you want to evaluate it further. If you do, you can request a trial.

      Network connection is required for the 7-day free license to work.

    If the test doesn't go as expected, you can check out the FAQ or contact us.

    Building your own page

    Include the library

    Use a CDN

    The simplest way to include the library is to use either the jsDelivr or UNPKG CDN. The "hello world" example above uses jsDelivr.

    • jsDelivr

      <script src="https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.6.1/dist/dbr.js"></script>
    • UNPKG

      <script src="https://unpkg.com/dynamsoft-javascript-barcode@8.6.1/dist/dbr.js"></script>

    Host the library yourself (recommended)

    Besides using the CDN, you can also download the library and host its files on your own website / server before including it in your application.

    The following shows a few ways to download the library.

    Depending on how you downloaded the library and where you put it. You can typically include it like this:

    <script src="/DBR-JS-8.6.1/dist/dbr.js"></script>

    or

    <script src="/node_modules/dynamsoft-javascript-barcode/dist/dbr.js"></script>

    Read more on how to host the library.

    Configure the library

    Before using the library, you need to configure a few things.

    Specify the license

    The library requires a license to work, use the APIs organizationID and handshakeCode to specify how to acquire the license.

    Dynamsoft.DBR.BarcodeScanner.organizationID = "YOUR-ORGANIZATION-ID"; // Required.
    Dynamsoft.DBR.BarcodeScanner.handshakeCode = "A-SPECIFIC-HANDSHAKECODE"; // Optional, if not specified, the default handshake code is used.
    Dynamsoft.DBR.BarcodeScanner.sessionPassword = "PASSWORD-TO-PROTECT-YOUR-LICENSE"; // Optional but recomended, use it to protect your license.
    Dynamsoft.DBR.BarcodeScanner.licenseServer = ["YOUR-OWN-MAIN-DLS", "YOUR-OWN-STANDBY-DLS"]; //Optional, ignore this line if you are using Dynamsoft-hosting DLS.

    Note:

    • Network connection is required for the license to work.
    • If nothing is specified, a 7-day free license will be used by default which is the case in the above "hello world" example.
    • The license is actually fetched during the creation of a BarcodeScanner or BarcodeReader instance.
    • If a public network connection is not available, you can choose to host a license server in your private network.

    An alternative way to specify the license is to use an alphanumeric string which does not require a network connection. The following shows how it could be used. Contact us for more information.

    Dynamsoft.DBR.BarcodeReader.productKeys = "t0068NQAAACgTVU2aucyxqETXKkiomqhV7YoLrnqjLiQQRSH5DBV1UtIs4..."

    Or

    <script src="https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.6.1/dist/dbr.js" data-productKeys="t0068NQAAACgTVU2aucyxqETXKkiomqhV7YoLrnqjLiQQRSH5DBV1UtIs4..."></script>

    Specify the location of the "engine" files

    The "engine" files refer to *.worker.js, *.wasm.js and *.wasm, etc. which are loaded by the main library at runtime. This configuration option uses the API engineResourcePath and is often not required as these files usually are in the same location with the main library file (dbr.js). However, in cases where the engine files are not in the same location as the main library file (for example, with frameworks like Angular or React, dbr.js is compiled into another file), this configuration will be required.

    The following code uses the jsDelivr CDN, feel free to change it to your own location of these files.

    import DBR from "dynamsoft-javascript-barcode";
    DBR.BarcodeScanner.engineResourcePath = "https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.6.1/dist/";
    export default DBR;

    Interact with the library

    Create a BarcodeScanner object

    You can use one of two classes ( BarcodeScanner and BarcodeReader ) to interact with the library. BarcodeReader is a low-level class that processes images directly. BarcodeScanner , on the other hand, inherits from BarcodeReader and provides high-level APIs and a built-in GUI to allow continuous barcode scanning on video frames. We'll focus on BarcodeScanner in this guide.

    To use the library, we first create a BarcodeScanner object.

    try {
      await Dynamsoft.DBR.BarcodeScanner.createInstance();
    } catch (ex) {
      console.error(ex);
    }

    Note:

    • The creation of an object consists of two parallel tasks: one is to download and compile the "engine", the other is to fetch a license from Dynamsoft License Server (assuming an online license is used).

    Configure the BarcodeScanner object

    Let's take a look at the following code snippets first:

    // set which camera and what resolution to use
    var allCameras = await scanner.getAllCameras();
    await scanner.setCurrentCamera(allCameras[0].deviceId);
    await scanner.setResolution(1280, 720);
    // set up the scanner behavior
    let scanSettings = await scanner.getScanSettings();
    // disregard duplicated results found in a specified time period (in milliseconds)
    scanSettings.duplicateForgetTime = 5000;
    // set a scan interval in milliseconds so the library may release the CPU from time to time
    scanSettings.intervalTime = 300;
    await scanner.updateScanSettings(scanSettings);
    // use one of the built-in RuntimeSetting templates: "single" (decode a single barcode, the default mode), "speed", "balance" and "coverage".
    await scanner.updateRuntimeSettings("speed");
    
    // make changes to the template. The code below demonstrates how to specify enabled symbologies
    let runtimeSettings = await scanner.getRuntimeSettings();
    runtimeSettings.barcodeFormatIds = Dynamsoft.DBR.EnumBarcodeFormat.BF_ONED | Dynamsoft.DBR.EnumBarcodeFormat.BF_QR_CODE;
    await scanner.updateRuntimeSettings(runtimeSettings);

    Try in JSFiddle

    As you can see from the above code snippets, there are three types of configurations:

    • get/updateVideoSettings: Configures the data source, i.e., the camera. These settings include which camera to use, the resolution, etc. Learn more here.

    • get/updateScanSettings: Configures the behavior of the scanner which includes duplicateForgetTime, intervalTime and filter, etc.

    • get/updateRuntimeSettings: Configures the decode engine. Find a full list of these settings and their corresponding descriptions here. For example, the following uses the built-in "speed" settings with updated localizationModes.

      await barcodeScanner.updateRuntimeSettings("speed");
      //await barcodeScanner.updateRuntimeSettings("balance"); //alternative
      //await barcodeScanner.updateRuntimeSettings("coverage"); //alternative
      let settings = await barcodeScanner.getRuntimeSettings();
      settings.localizationModes = [
          Dynamsoft.DBR.EnumLocalizationMode.LM_CONNECTED_BLOCKS,
          Dynamsoft.DBR.EnumLocalizationMode.LM_SCAN_DIRECTLY,
          Dynamsoft.DBR.EnumLocalizationMode.LM_LINES, 0, 0, 0, 0, 0
      ];
      await barcodeScanner.updateRuntimeSettings(settings);

      Try in JSFiddle.

      See also settings samples.

    Customize the UI

    The built-in UI of the BarcodeScanner object is defined in the file dist/dbr.scanner.html . There are a few ways to customize it:

    • Modify the file dist/dbr.scanner.html directly.

      This option is only possible when you host this file on your own web server instead of using a CDN.

    • Copy the file dist/dbr.scanner.html to your application, modify it and use the the API defaultUIElementURL to set it as the default UI.

      Dynamsoft.DBR.BarcodeScanner.defaultUIElementURL = "THE-URL-TO-THE-FILE";

      You must set defaultUIElementURL before you call createInstance() .

    • Append the default UI element to your page, customize it before showing it.

      <div id="scannerUI"></div>
      document.getElementById('scannerUI').appendChild(scanner.getUIElement());
      document.getElementsByClassName('dbrScanner-btn-close')[0].hidden = true; // Hide the close button
    • Build the UI element into your own web page and specify it with the API setUIElement(HTMLElement).

      • Embed the video

        <div id="div-video-container">
          <video class="dbrScanner-video" playsinline="true" style="width:100%;height:100%;position:absolute;left:0;top:0;"></video>
        </div>
        <script>
          let pScanner = null;
          (async()=>{
            let scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
            await scanner.setUIElement(document.getElementById('div-video-container'));
            scanner.onFrameRead = results => {console.log(results);};
            scanner.onUnduplicatedRead = (txt, result) => {alert(txt);};
            await scanner.show();
          })();
        </script>

        The video element must have the class dbrScanner-video .

        Try in JSFiddle

      • Add the camera list and resolution list

        If the class names for these lists match the default ones, dbrScanner-sel-camera and dbrScanner-sel-resolution , the library will automatically populate the lists and handle the camera/resolution switching.

        <select class="dbrScanner-sel-camera"></select>

        Try in JSFiddle

        <select class="dbrScanner-sel-resolution"></select>

        Try in JSFiddle

        By default, 8 hard-coded resolutions are populated as options. You can show only a custom set of options by hardcoding them.

        <select class="dbrScanner-sel-resolution">
          <option class="dbrScanner-opt-gotResolution" value="got"></option>
          <option data-width="1920" data-height="1080">1920 x 1080</option>
          <option data-width="1280" data-height="720">1280 x 720</option>
          <option data-width="640" data-height="480">640 x 480</option>
        </select>

        Try in JSFiddle

        Generally, you need to provide a resolution that the camera supports. However, in case a camera does not support the specified resolution, it usually uses the nearest supported resolution. As a result, the selected resolution may not be the actual resolution used. In this case, add an option with the class name dbrScanner-opt-gotResolution (as shown above) and the library will then use it to show the actual resolution.

    See also UI customization samples.

    Interested to test it further? Read on to learn how to request a 30-day free trial.

    Requesting A Trial

    From version 8.2.5 of the library, if no license is specified, a 7-day free license will be used by default.

    Network connection is required for the 7-day free license to work.

    After that, if you want to evaluate the library further, you can register for a Dynamsoft account (if you haven't already done so) and request a 30-day trial in the customer portal.

    System Requirements

    This library requires the following features which are supported by all modern mainstream browsers:

    • WebAssembly, Blob, URL/createObjectURL, Web Workers

      The above four features are required for the library to work.

    • MediaDevices/getUserMedia

      This API is only required for in-browser video streaming. If a browser does not support this API, the Single Frame Mode will be used automatically. If the API exists but doesn't work correctly, the Single Frame Mode can be used as an alternative way to access the camera.

    The following table is a list of supported browsers based on the above requirements:

    Browser Name Version
    Chrome v57+ (v59+ on Android/iOS1)
    Firefox v52+ (v55+ on Android/iOS1)
    Edge2 v16+
    Safari3 v11+

    1 iOS 14.3+ is required for camera video streaming in Chrome and Firefox or Apps using webviews.

    2 On Edge, due to strict Same-origin policy, you must host the library files on the same domain as your web page.

    3 Safari 11.2.2 ~ 11.2.6 are not supported.

    Apart from the browsers, the operating systems may impose some limitations of their own that could restrict the use of the library. Browser compatibility ultimately depends on whether the browser on that particular operating system supports the features listed above.

    Hosting the library

    Step One: Deploy the dist folder

    Once you have downloaded the library, you can locate the "dist" directory and copy it to your server (usually as part of your website / web application). The following shows some of the files in this directory:

    • dbr.js // The main library file
    • dbr.browser.mjs // For using the library as a module (<script type="module">)
    • dbr.scanner.html // Defines the default scanner UI
    • dbr-<version>.worker.js // Defines the worker thread for barcode reading
    • dbr-<version>.wasm.js // Compact edition of the library (.js)
    • dbr-<version>.wasm // Compact edition of the library (.wasm)
    • dbr-<version>.full.wasm.js // Full edition of the library (.js)
    • dbr-<version>.full.wasm // Full edition of the library (.wasm)

    Step Two: Configure the Server

    • Set the MIME type for .wasm as application/wasm on your webserver.

      The goal is to configure your server to send the correct Content-Type header for the wasm file so that it is processed correctly by the browser.

      Different types of webservers are configured differently, for example:

    • Enable HTTPS

      To use the library, you must access your website / web application via a secure HTTPS connection. This is due to browser security restrictions which only grant camera video streaming access to a secure context.

      For convenience, self-signed certificates are allowed during development and testing.

    Step Three: Include the library from the server

    Now that the library is hosted on your server, you can include it accordingly.

    <script src="https://www.yourwebsite.com/dynamsoft-javascript-barcode/dist/dbr.js"></script>

    Optionally, you may also need to (specify the location of the "engine" files)[#specify-the-location-of-the-engine-files].

    Advanced Usage

    Read a specific area/region

    To speed up the scanning process, you can choose to scan only a specific area/region.

    let settings = await scanner.getRuntimeSettings();
    /*
     * The following code shrinks the decoding region by 25% on all sides
     */
    settings.region.regionMeasuredByPercentage = 1;
    settings.region.regionLeft = 25;
    settings.region.regionTop = 25;
    settings.region.regionRight = 75;
    settings.region.regionBottom = 75;
    await scanner.updateRuntimeSettings(settings);

    Try in JSFiddle

    Show internal logs

    Include the following in your code to print internal logs in the console.

    Dynamsoft.DBR.BarcodeReader._onLog = console.log;

    Set mode arguments

    To precisely control a mode, you can adjust its specific parameters.

    let settings = await scanner.getRuntimeSettings();
    
    /*
     * The following code sets the sensitivity of the TextureDetectionModes to 9
     */
    
    settings.furtherModes.textureDetectionModes = [
        Dynamsoft.DBR.EnumTextureDetectionMode.TDM_GENERAL_WIDTH_CONCENTRATION, 0, 0, 0, 0, 0, 0, 0
    ];
    
    await scanner.updateRuntimeSettings(settings);
    // The 2nd parameter 0 specifies the first mode of TextureDetectionModes, which is "Dynamsoft.DBR.EnumTextureDetectionMode.TDM_GENERAL_WIDTH_CONCENTRATION" in this case.
    await scanner.setModeArgument("TextureDetectionModes", 0, "Sensitivity", "9");

    Display the intermediate result images or the original canvas

    The intermediate result images are created when intermediateResultTypes is set in RuntimeSettings . Then they can be returned with the method getIntermediateResults() . These images can be used to show and debug the barcode reading process.

    The original canvas ( oriCanvas ) means the actual canvas which holds the image to be passed to the barcode reader engine for decoding.

    NOTE

    For efficiency, the library may utilize WebGL (Web Graphics Library) for preprocessing an image before passing it to the barcode reader engine. If WebGL is used, the image captured from the camera will not be rendered on the canvas, instead, it gets processed by WebGL first and then is passed to the barcode reader engine directly. In this case, there won't be an original canvas. Therefore, if bSaveOriCanvas is set to true for a BarcodeReader or BarcodeScanenr instance, the WebGL feature will be disabled for that instance.

    On the other hand, if WebGL is disabled and you try to get the intermediate result specified by EnumIntermediateResultType. IRT_ORIGINAL_IMAGE , it will be exactly the same image as you would get with oriCanvas .

    The following shows how to display these images on the page

    <div id='scannerV' style="width:50vw;height:50vh"></div>
    <div id='cvses'></div>
    let pScanner = null;
    (async () => {
        let scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
        /* The default of `_bUseWebgl` is true which means the intermediate result for  
           IRT_ORIGINAL_IMAGE will be one that has been preprocessed by WebGL */
        scanner._bUseWebgl = false;
        document.getElementById('scannerV').appendChild(scanner.getUIElement());;
        await scanner.updateRuntimeSettings('balance');
        let rs = await scanner.getRuntimeSettings();
        rs.intermediateResultTypes = 1;
        await scanner.updateRuntimeSettings(rs);
        scanner.onUnduplicatedRead = async (txt, result) => {
            try {
                let cvss = await scanner.getIntermediateCanvas();
                for (let cvs of cvss) {
                    document.getElementById('cvses').appendChild(cvs);
                }
                scanner.destroy();
            } catch (ex) {
                console.error(ex);
            }
        };
        await scanner.show();
    })();

    How to Upgrade

    If you are using an older version of the library and want to upgrade it to the latest version, please read more on how to upgrade.

    FAQ

    Can I open the web page directly from the hard drive?

    Yes, for simple testing purposes, it's perfectly fine to open the file directly from the hard drive. However, you might encounter some issues in doing so (like unable to access the camera, etc.). The recommendation is to deploy this page to your web server and run it over HTTPS. If you don't have a ready-to-use web server but have a package manager like npm or yarn, you can set up a simple HTTP server in minutes. Check out http-server on npm or yarn.

    Why can't I use my camera?

    If you open the web page as file:/// or http://, the camera may not work and you see the following error in the browser console:

    [Deprecation] getUserMedia() no longer works on insecure origins. To use this feature, you should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.

    • In Safari 12 the equivalent error is:

    Trying to call getUserMedia from an insecure document.

    You get this error because the API getUserMedia requires HTTPS to access the camera.

    • If you use Chrome or Firefox, you might not get the error because these two browsers allow camera access via file:/// and http://localhost.

    To make sure your web application can access the camera, please configure your web server to support HTTPS. The following links may help.

    Install

    npm i dynamsoft-javascript-barcode

    DownloadsWeekly Downloads

    5,427

    Version

    8.6.1

    License

    SEE LICENSE IN LICENSE.txt

    Unpacked Size

    14.3 MB

    Total Files

    246

    Last publish

    Collaborators

    • yushulx
    • dm_npm_publisher
    • ellie-dynamsoft