10 examples of 'convert file to base64 javascript' in JavaScript

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function base64_encode(file) {
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  var bitmap = fs.readFileSync(file);
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  var h;
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  if (file.endsWith(".png")) {
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    h = "data:image/png;base64, ";
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  } else {
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    h = "data:image/jpeg;base64, ";
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  }
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  return h + Buffer.from(bitmap).toString("base64");
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}

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export function fileToBase64(file: File): Promise<data> {
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  return new Promise<data>((resolve, reject) =&gt; {
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    if (!/^image\/\w+$/.test(file.type)) {
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      reject('Invalid image file');
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    }
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    const reader = new FileReader();
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    reader.onload = (e) =&gt; {
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      const img = new Image();
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      const fileData = (e.target as any).result;
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      img.onload = () =&gt; {
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        resolve({
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          url: fileData,
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          data: fileData.split(',')[1],
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          filename: file.name,
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          contentType: file.type,
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          width: img.width,
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          height: img.height
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        });
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      };
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      try {
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        img.src = fileData;
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      } catch (e) {
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        reject(e);
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      }
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    };
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    reader.readAsDataURL(file);
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  });
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}</data></data>

277
async function fileToBase64(filePath: string) {
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  const data = await new Promise((resolve, reject) => {
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    readFile(filePath, (err, data) => {
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      if (err) {
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        return reject(err);
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      }
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      resolve(data);
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    });
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  });
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  return data.toString("base64");
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}

126
function encodeBase64 (filePath, callback) {
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    var sandbox = window.qnx.webplatform.getController().setFileSystemSandbox; // save original sandbox value
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    var errorHandler = function (err) {
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        var msg = 'An error occured: ';
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        switch (err.code) {
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        case FileError.NOT_FOUND_ERR:
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            msg += 'File or directory not found';
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            break;
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        case FileError.NOT_READABLE_ERR:
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            msg += 'File or directory not readable';
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            break;
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        case FileError.PATH_EXISTS_ERR:
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            msg += 'File or directory already exists';
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            break;
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        case FileError.TYPE_MISMATCH_ERR:
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            msg += 'Invalid file type';
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            break;
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        default:
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            msg += 'Unknown Error';
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            break;
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        }
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        // set it back to original value
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        window.qnx.webplatform.getController().setFileSystemSandbox = sandbox;
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        callback(msg);
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    };
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    var gotFile = function (fileEntry) {
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        fileEntry.file(function (file) {
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            var reader = new FileReader();
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            reader.onloadend = function (e) {
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                // set it back to original value
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                window.qnx.webplatform.getController().setFileSystemSandbox = sandbox;
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                callback(this.result);
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            };
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            reader.readAsDataURL(file);
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        }, errorHandler);
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    };
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    var onInitFs = function (fs) {
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        window.qnx.webplatform.getController().setFileSystemSandbox = false;
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        fs.root.getFile(filePath, {create: false}, gotFile, errorHandler);
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    };
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    window.webkitRequestFileSystem(window.TEMPORARY, 10 * 1024 * 1024, onInitFs, errorHandler); // set size to 10MB max
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}

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function decodeBase64 (fileContent) {
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  var buf = new Buffer(fileContent, 'base64');
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  return buf.toString();
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}

18
function jsToUrl(path, js) {
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  var url = urls[path];
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  if (url) window.URL.revokeObjectURL(url);
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  var blob = new Blob([js], { type: "application/javascript" });
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  return (urls[path] = window.URL.createObjectURL(blob));
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}

181
function getBase64Contents(contents) {
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  return contents.replace(/^data:image\/(jpeg|png)+;base64,/, '');
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}

14
function _arrayBufferToBase64(buffer) {
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  var binary = '';
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  var bytes = new Uint8Array(buffer);
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  var len = bytes.byteLength;
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  for (var i = 0; i < len; i++) {
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    binary += String.fromCharCode(bytes[i]);
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  }
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  return btoa(binary);
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}

32
function base64Decode(base64) {
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    base64 = base64.replace(/\*/g,'+').replace(/-/g,'/').replace(/\_/g,'=');
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    let result = new Buffer(base64, 'base64').toString();    
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    return result;
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}

285
getBase64(src, { width, height, x, y }) {
286
  return new Promise((resolve, reject) => {
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    const img = new Image();
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    img.crossOrigin = 'Anonymous'; // 允许跨域
289
    img.onload = () => {
290
      const canvas = $('')[0];
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      const ctx = canvas.getContext('2d');
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      ctx.drawImage(img, x, y, width, height, 0, 0, width, height);
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      resolve(canvas.toDataURL());
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    };
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    img.onerror = err => {
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      console.error('图片转base64失败！');
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      reject(err);
298
    };
299
    img.src = src + '?t=' + this.randomID();
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  });
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}