The capturedImage state, which holds a Base64 version of an image.
A boolean captured state, which specifies whether an image has been captured.
An uploading state, which specifies if an image is being uploaded to Cloudinary.
When the ClCamera component is mounted, the componentDidMount()function creates a canvas element and a Webcam object, passing the videoElement and canvasElement elements as parameters. Afterwards, you initialize the camera feed.
When the app goes from offline to online mode, the componentDidUpdatemethod calls the batchUpload() method for uploading the images that were saved in the browser’s cache while the app was offline.
Here are the other methods that perform tasks in your app:
When the captureImage() function is clicked, the takeBase64Photo() method is called to capture the image.
The Base64 image is stored in the capturedImage state of ClCamera with the captured state of the component set to true.
Two buttons are displayed, which trigger the discardImage method and the uploadImage method, prompting you to either discard or upload the image, respectively. The discardImage() method discards the image from the state of ClCamera and then sets the captured state to false.
The uploadImage function checks your connection status and then does the following:
If the connection is offline, uploadImage creates a new unique string with the prefix cloudy_pwa_ and then stores your Base64 image in the component’s this.state.capturedImage state in the browser’s localStorage. Finally, uploadImage calls the discardImage()method.
If the connection is online, uploadImage makes a POST request to upload your Base64 image along with a Cloudinary Preset as a parameter.
Note: Cloudinary Upload Presets are described in depth later in this tutorial.
// src/components/ClCamera/index.js
[...]
uploadImage = () => {
if (this.props.offline) {
console.log("you're using in offline mode sha");
// create a random string with a prefix
const prefix = 'cloudy_pwa_';
// create random string
const rs = Math.random().toString(36).substr(2, 5);
localStorage.setItem(`${prefix}${rs}`, this.state.capturedImage);
alert('Image saved locally, it will be uploaded to your Cloudinary media library once internet connection is detected');
this.discardImage();
// save image to local storage
} else {
this.setState({ 'uploading': true });
axios.post(
`https://api.cloudinary.com/v1_1/CLOUDINARY_CLOUD_NAME/image/upload`,
{
file: this.state.capturedImage,
upload_preset: 'CLOUDINARY_CLOUD_PRESET'
}
).then((data) => this.checkUploadStatus(data)).catch((error) => {
alert('Sorry, we encountered an error uploading your image');
this.setState({ 'uploading': false });
});
}
}
[...]
Note: Be sure to replace CLOUDINARY_CLOUD_NAME and CLOUDINARY_UPLOAD_PRESET with the actual values in your setup. See the next section for how to obtain those values.
When ClCamera detects that your Internet connection has been restored, the batchUploads method is called, which searches localStorage for any previously stored images with the findLocalItems method. If no images are found, the function exits. Otherwise, the images are uploaded to the Cloudinary media library through a POST request to the upload endpoint with the image and preset as parameters. The checkUploadStatus method accepts the data response from Cloudinary’s API and then checks if the upload succeeded. In case of an error, checkUploadStatus displays a message to the effect that the image remains in localStorage for the next batch upload.
findLocalItems = (query) => {
let i;
let results = [];
for (i in localStorage) {
if (localStorage.hasOwnProperty(i)) {
if (i.match(query) || (!query && typeof i === 'string')) {
const value = localStorage.getItem(i);
results.push({ key: i, val: value });
}
}
}
return results;
}
checkUploadStatus = (data) => {
this.setState({ 'uploading': false });
if (data.status === 200) {
alert('Image Uploaded to Cloudinary Media Library');
this.discardImage();
} else {
alert('Sorry, we encountered an error uploading your image');
}
}
batchUploads = () => {
// this is where all the images saved can be uploaded as batch uploads
const images = this.findLocalItems(/^cloudy_pwa_/);
let error = false;
if (images.length > 0) {
this.setState({ 'uploading': true });
for (let i = 0; i < images.length; i++) {
// upload
axios.post(
`https://api.cloudinary.com/v1_1/CLOUDINARY_CLOUD_NAME/image/upload`,
{
file: images[i].val,
upload_preset: 'CLOUDINARY_CLOUD_PRESET'
}
).then(
(data) => this.checkUploadStatus(data)
).catch((error) => {
error = true;
})
}
this.setState({ 'uploading': false });
if (!error) {
alert("All saved images have been uploaded to your Cloudinary Media Library");
}
}
}
}
export default ClCamera;
Note: Again, replace CLOUDINARY_CLOUD_NAME and CLOUDINARY_UPLOAD_PRESET with the actual values in your setup. See the next section for how to obtain those values.
The ClCamera component contains these style properties:
