@selfcommunity/utils/lib/esm/utils/image.js

Utilities to integrate a Community.

const dataURItoBlob = (dataURI) => {
    // convert base64/URLEncoded data component to raw binary data held in a string
    let byteString;
    if (dataURI.split(',')[0].indexOf('base64') >= 0)
        byteString = atob(dataURI.split(',')[1]);
    else
        byteString = unescape(dataURI.split(',')[1]);
    // separate out the mime component
    let mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
    // write the bytes of the string to a typed array
    let ia = new Uint8Array(byteString.length);
    for (let i = 0; i < byteString.length; i++) {
        ia[i] = byteString.charCodeAt(i);
    }
    return new Blob([ia], { type: mimeString });
};
const resizeImage = (file) => new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = (event) => {
        let image = new Image();
        image.onload = function (imageEvent) {
            // Resize the image
            let canvas = document.createElement('canvas'), max_size = 1920, width = image.width, height = image.height;
            if (width > height) {
                if (width > max_size) {
                    height *= max_size / width;
                    width = max_size;
                }
            }
            else {
                if (height > max_size) {
                    width *= max_size / height;
                    height = max_size;
                }
            }
            canvas.width = width;
            canvas.height = height;
            canvas.getContext('2d').drawImage(image, 0, 0, width, height);
            resolve(dataURItoBlob(canvas.toDataURL('image/jpeg')));
        };
        image.src = event.target.result;
    };
    reader.onerror = reject;
    reader.readAsDataURL(file);
});
export { resizeImage };