How to use blob-util - 10 common examples

convertImgToBlob(`https://www.thetvdb.com/banners/${res.filename}`).then(blob => {
								db.insert({
									_id: `img${tvelem.show.replace(' ', '')}S${tvelem.season}E${tvelem.episode}`,
									elempath: data[2],
									elem: data[0],
									tvelem: data[1],
									imgData: blob
								});
								blobUtil.base64StringToBlob(blob, 'image/jpeg').then(blob => {
									console.info(blob);
									img.children[0].style.backgroundImage = `url(${URL.createObjectURL(blob)})`; // eslint-disable-line
								}).catch(err => {
									Raven.captureException(err);
									Raven.showReportDialog();
								});
							});
						} else if (res.filename === '') {

async function addPlantLocalforage (state, meta) {
  // FIXME: This is generally a bad idea. Use feature detection instead.
  // However, I could not find a reliable way to test if IndexedDB supports blobs,
  // as it fails silently. We have to convert the blob to base64,
  // because mobile Safari 10 has a bug with storing Blobs in IndexedDB.

  if (iOS && !!meta.blob) {
    const base64String = await blobToBase64String(meta.blob)
    await addEntryLF(namespace + meta.guid, { ...meta, blob: base64String })
  } else {
    await addEntryLF(namespace + meta.guid, meta)
  }
}

const qrCodeAsBase64 = await ScanExchangeHelper.generateQRCode(scanDocData.shortLink)
        scanDocData.qrCodeAsBase64 = qrCodeAsBase64
      }

      if (
        scanDocData.status === ScanExchangerCodes.Step07_ResultIsAvailable &&
        (scanDocData.result || scanDocData.resultUrl)
      ) {
        let scanResultDec
        if (scanDocData.result) {
          scanResultDec = CryptoHelper.decrypt(scanDocData.result, secretKey)
        } else if (scanDocData.resultUrl) {
          const resultUrl = CryptoHelper.decrypt(scanDocData.resultUrl, secretKey)
          const response = await fetch(resultUrl)
          const blob = await response.blob()
          const text = await blobToBase64String(blob)
          scanDocData.result = text
          scanResultDec = CryptoHelper.decrypt(text, secretKey)
          firebase
            .storage()
            .refFromURL(resultUrl)
            .delete()
        }
        // Notify success listeners
        this.notifyOnSuccessListeners({ result: scanResultDec, sourceBlob: null }, true)

        // After successfully read 'result', remove it from the Firestore
        scan.update({
          result: null,
          resultUrl: null
        })

db.find({_id: `img${tvelem.show.replace(' ', '')}S${tvelem.season}E${tvelem.episode}`}, (err, doc) => {
							if (err) {
								Raven.captureException(err);
								Raven.showReportDialog();
							}
							blobUtil.base64StringToBlob(doc[0].imgData, 'image/jpeg').then(blob => {
								img.children[0].style.backgroundImage = `url(${URL.createObjectURL(blob)})`; // eslint-disable-line
								resolve(['got from db']);
							}).catch(err => {
								Raven.captureException(err);
								Raven.showReportDialog();
							});
						});
					}

exports.makeVideoThumbnail = async ({
  size,
  videoObjectUrl,
  logger,
  contentType,
}) => {
  let screenshotObjectUrl;
  try {
    const blob = await exports.makeVideoScreenshot({
      objectUrl: videoObjectUrl,
      contentType,
      logger,
    });
    const data = await blobToArrayBuffer(blob);
    screenshotObjectUrl = arrayBufferToObjectURL({
      data,
      type: contentType,
    });

    // We need to wait for this, otherwise the finally below will run first
    const resultBlob = await exports.makeImageThumbnail({
      size,
      objectUrl: screenshotObjectUrl,
      contentType,
      logger,
    });

    return resultBlob;
  } finally {
    exports.revokeObjectUrl(screenshotObjectUrl);

exports.autoOrientJPEG = async attachment => {
  if (!MIME.isJPEG(attachment.contentType)) {
    return attachment;
  }

  // If we haven't downloaded the attachment yet, we won't have the data
  if (!attachment.data) {
    return attachment;
  }

  const dataBlob = await arrayBufferToBlob(
    attachment.data,
    attachment.contentType
  );
  const newDataBlob = await dataURLToBlob(await autoOrientImage(dataBlob));
  const newDataArrayBuffer = await blobToArrayBuffer(newDataBlob);

  // IMPORTANT: We overwrite the existing `data` `ArrayBuffer` losing the original
  // image data. Ideally, we’d preserve the original image data for users who want to
  // retain it but due to reports of data loss, we don’t want to overburden IndexedDB
  // by potentially doubling stored image data.
  // See: https://github.com/signalapp/Signal-Desktop/issues/1589
  const newAttachment = Object.assign({}, attachment, {
    data: newDataArrayBuffer,
    size: newDataArrayBuffer.byteLength,
  });

  // `digest` is no longer valid for auto-oriented image data, so we discard it:
  delete newAttachment.digest;

  return newAttachment;
};

async function showPage(pageId) {
    const page = await getPage({pageId, followRedirects: true})
    if (page._id !== pageId) {
        // Apparently getPage followed one or more redirects. Reload the viewer
        // with the resolved page's id in the ?page query.
        const location = new URL(window.location)
        location.searchParams.set('page', page._id)
        window.location = location
    }
    const timestamp = getTimestamp(page)

    // Read the html file from the database.
    const blob = await db.getAttachment(pageId, 'frozen-page.html')
    // We assume utf-8 encoding. TODO: read encoding from document.
    const html = new TextDecoder('utf-8').decode(await blobToArrayBuffer(blob))

    document.title = `📄 ${page.title}`

    const bar = (
        <div id="bar">
            <span id="description">
                
                Snapshot of
                <a style="{{margin:" href="{page.url}">
                    {shortUrl(page.url)}
                </a>
                
                <time datetime="{new">
                    {niceTime(timestamp)}
                </time>
            </span></div>

export async function stringToDataUrl(string, type='text/plain') {
    // Using self.btoa is faster but fails for unicode strings.
    const blob = new Blob([string], {type})
    const dataUrl = await blobToDataURL(blob)
    return dataUrl
}

// If we got passed the doc itself, we can check whether the attachment exists.
        (doc && !get(['_attachments', attachmentId, 'digest'])(doc))
    ) {
        return undefined
    }
    let blobOrBuffer
    try {
        blobOrBuffer = await db.getAttachment(docId, attachmentId)
    } catch (err) {
        return undefined
    }
    const contentType = get(['_attachments', attachmentId, 'content_type'])(doc)
    const isBrowser = typeof window !== 'undefined' && !window.process
    const blob = isBrowser
        ? blobOrBuffer
        : await arrayBufferToBlob(blobOrBuffer, contentType)
    const base64 = await blobToBase64String(blob)
    const dataUrl = `data:${blob.type};base64,${base64}`
    return dataUrl
}

exports.autoOrientJPEG = async attachment => {
  if (!MIME.isJPEG(attachment.contentType)) {
    return attachment;
  }

  // If we haven't downloaded the attachment yet, we won't have the data
  if (!attachment.data) {
    return attachment;
  }

  const dataBlob = await arrayBufferToBlob(
    attachment.data,
    attachment.contentType
  );
  const newDataBlob = await dataURLToBlob(await autoOrientImage(dataBlob));
  const newDataArrayBuffer = await blobToArrayBuffer(newDataBlob);

  // IMPORTANT: We overwrite the existing `data` `ArrayBuffer` losing the original
  // image data. Ideally, we’d preserve the original image data for users who want to
  // retain it but due to reports of data loss, we don’t want to overburden IndexedDB
  // by potentially doubling stored image data.
  // See: https://github.com/signalapp/Signal-Desktop/issues/1589
  const newAttachment = Object.assign({}, attachment, {
    data: newDataArrayBuffer,
    size: newDataArrayBuffer.byteLength,
  });