Guidelines

Vanilla HTML

Follow these steps to get started with Vanilla HTML.

  1. Prepare a folder/directory. For this tutorial, we'll be using this directory structure:

    project-root/
    |
    +-- ocr/
    |
    \-- index.html

    The ocr folder/directory should contain the ocr engine and builders like builder.js.

  2. Populate index.html. We will add more later.

    <!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <!-- script and style definitions -->
  </head>
  <body>
    <!-- body -->
  </body>
</html>

    The imports section will be populated with script imports and style for better demo UI, and the body section will be populated with some html elements and a script to be loaded after the html elements are loaded.

  3. Replace #!html <!-- script and style definitions --> with script tag below.

            <title>Document</title>
        <script src="./ocr/builder.js"></script>
        <style>
            #data-result {
                font-family: 'Courier New', Courier, monospace;
                white-space: pre-wrap;
                background-color: #0002;
                overflow: auto;
            }
        </style>
    </head>

    The script tag above will import the WebSDK builder to be used in the tutorial application. It will then populate a Builder class in the window global object. The style tag will then be used to style the data returned by the OCR WebSDK.

  4. Replace #!html <!-- body --> with some HTML elements, as shown below.

        </head>
    <body>
        <button onclick="doOCRProcess()">
            Run OCR Process
        </button>
        <img id="image-result" src="" />
        <div id="data-result"></div>
        <script>
            ((global) => {
                // Create OCR WebSDK instance

                // Set up doOCRProcess global function

                // Set up message receiver for OCR WebSDK
            })(window);
        </script>
    </body>
    • The button element is for starting the OCR WebSDK process.
    • The image element with id image-result is for displaying the resulting image from the OCR WebSDK.
    • The div element with id data-result is for displaying data result of the OCR WebSDK.
    • The script element is used to prepare OCR WebSDK and data handling from the SDK.

  5. Replace #!js // Create OCR WebSDK instance with code below.

    ((global) => {
  global.OCRSDK = new OCRBuilder()
    .setAttemptCount(3)
    .setProxyMiddleware({
    	Correction: {
      	url: 'http://localhost:8888/ocr/extract/correction,
      },
      Extract: {
        url: 'http://localhost:8888/ocr/extract-async',
        headers: {
          'App-ID': '<replace-me-with-app-id>',
          'API-Key': '<replace-me-with-api-key>',
        },
      },
      ExtractResult: {
        url: 'http://localhost:8888/ocr/extract-async/result',
        headers: {
          'App-ID': '<replace-me-with-app-id>',
          'API-Key': '<replace-me-with-api-key>',
        },
      },
      License: {
        url: 'http://localhost:8888/license/{license_id}/check',
        headers: {
          'App-ID': '<replace-me-with-app-id>',
          'API-Key': '<replace-me-with-api-key>',
        },
      },
    })
    .setURL('/ocr')
    .build();

  // Set up doOCRProcess global function

  // Set up message receiver for OCR WebSDK
})(window);

    Replace proxy middleware URLs with a URL that points to the correct endoints, and replace <replace-me-with-app-id> and <replace-me-with-api-key> with the appropriate APP-ID and APIKey for the OCR (remove the headers if the api doesn't need credentials or the url is pointing towards an intermediate endpoint).

    🚧

    Look Out!

    To not accidentally leak of AppID and APIKey for OCR, always pass them to an intermediate endpoint (like a proxy middleware) and append the AppID and APIKey header before reaching Verihubs' OCR service in production. Additional data can also be passed to this intermediate endpoint for end user identification.

    For more information about creating a Proxy Middleware, refer to Proxy Middleware.

    For API documentation of the Builder, refer to Builder.

  6. Replace #!js // Set up doOCRProcess global function with code below.

                        .build();

                global.doOCRProcess = function() {
                    global.OCRSDK.onStart();
                };

                // Set up message receiver for OCR WebSDK
            })(window);

    The code above creates a global function doOCRProcess to be called by the button element. This function then invokes onStart function of the OCR WebSDK instance upon being called by the button element being clicked.

  7. Replace #!js // Set up message receiver for OCR WebSDK with code below.

                    };

                global.addEventListener('message', function (message) {
                    var data = message.data.data;
                    var subject = message.data.subject;
                    switch (subject) {
                        case "OCR.Verbose":
                            alert(data.message);
                            break;
                        case "Internal.Error":
                            switch (data.message) {
                                case "SANDBOX_ID_NOT_ALLOWED":
                                    alert("Invalid sandbox image code");
                                    global.OCRSDK.onDestroy();
                                    break;
                                case "INSUFFICIENT_QUOTA":
                                    alert("Insufficient quota");
                                    global.OCRSDK.onDestroy();
                                    break;
                                case "INTERNAL_SERVER_ERROR":
                                    alert("Internal server error occured.");
                                    break;
                                case "PROCESS_TIMEOUT":
                                    alert("KTP Extraction timeout.");
                                    break;
                                default:
                                    alert("An error occured. Please check the console.");
                                    console.log(data.message);
                                    break;
                            }
                            break;
                        case "OCR.Success":
                            const imageElement = document.getElementById('image-result');
                            const jsonElement = document.getElementById('data-result');
                            imageElement.src = data.image.url;
                            jsonElement.innerText = JSON.stringify(
                                data,
                                undefined,
                                2
                            );
                            setTimeout(() => {
                                global.OCRSDK.onDestroy();
                            }, 3000);
                            break;
                        case "OCR.Cancelled":
                        case "OCR.OutOfChance":
                            document.getElementById('data-result').innerText = data.message;
                            global.OCRSDK.onDestroy();
                            break;
                        case "Camera.NotFound":
                        case "Camera.PermissionDenied":
                            alert("Camera is not detected or permission denied"),
                            global.OCRSDK.onDestroy();
                            break;
                    }
                });
            })(window);

    📘

    Info

    Check System Messages for full system message references.

Combining all of the steps above, the full content file of index.html:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="./ocr/builder.js"></script>
    <style>
      #data-result {
        font-family: 'Courier New', Courier, monospace;
        white-space: pre-wrap;
        background-color: #0002;
        overflow: auto;
      }
    </style>
  </head>
  <body>
    <button onclick="doOCRProcess()">Run OCR Process</button>
    <img id="image-result" src="" />
    <div id="data-result"></div>
    <script>
      ((global) => {
        global.OCRSDK = new OCRBuilder()
          .setAttemptCount(3)
          .setProxyMiddleware({
          	Correction: {
      				url: 'http://localhost:8888/ocr/extract/correction,
      			},
            Extract: {
              url: 'http://localhost:8888/ocr/extract-async',
              headers: {
                'App-ID': '<replace-me-with-app-id>',
                'API-Key': '<replace-me-with-api-key>',
              },
            },
            ExtractResult: {
              url: 'http://localhost:8888/ocr/extract-async/result',
              headers: {
                'App-ID': '<replace-me-with-app-id>',
                'API-Key': '<replace-me-with-api-key>',
              },
            },
            License: {
              url: 'http://localhost:8888/license/{license_id}/check',
              headers: {
                'App-ID': '<replace-me-with-app-id>',
                'API-Key': '<replace-me-with-api-key>',
              },
            },
          })
          .setURL('/ocr')
          .build();

        global.doOCRProcess = function () {
          global.OCRSDK.onStart();
        };

        global.addEventListener('message', function (message) {
          var data = message.data.data;
          var subject = message.data.subject;
          switch (subject) {
            case 'OCR.Verbose':
              alert(data.message);
              break;
            case 'Internal.Error':
              switch (data.message) {
                case 'SANDBOX_ID_NOT_ALLOWED':
                  alert('Invalid sandbox image code');
                  global.OCRSDK.onDestroy();
                  break;
                case 'INSUFFICIENT_QUOTA':
                  alert('Insufficient quota');
                  global.OCRSDK.onDestroy();
                  break;
                case 'INTERNAL_SERVER_ERROR':
                  alert('Internal server error occured.');
                  break;
                case 'PROCESS_TIMEOUT':
                  alert('KTP Extraction timeout.');
                  break;
                default:
                  alert('An error occured. Please check the console.');
                  console.log(data.message);
                  break;
              }
              break;
            case 'OCR.Success':
              const imageElement = document.getElementById('image-result');
              const jsonElement = document.getElementById('data-result');
              imageElement.src = data.image.url;
              jsonElement.innerText = JSON.stringify(data, undefined, 2);
              setTimeout(() => {
                global.OCRSDK.onDestroy();
              }, 3000);
              break;
            case 'OCR.Cancelled':
            case 'OCR.OutOfChance':
              document.getElementById('data-result').innerText = data.message;
              global.OCRSDK.onDestroy();
              break;
            case 'Camera.NotFound':
            case 'Camera.PermissionDenied':
              alert('Camera is not detected or permission denied'),
                global.OCRSDK.onDestroy();
              break;
          }
        });
      })(window);
    </script>
  </body>
</html>

To try the above implementation, you can host the folder/directory as the root of a HTTP server.

Updated about 2 months ago