2.5 KiB
Content service
Accesses app-generated data objects via URLs and file downloads.
Methods
downloadBlob(blob: Blob, fileName: string): void
Starts downloading the data in blob to a named file.
downloadData(data: any, fileName: string): void
Starts downloading a data object to a named file.
downloadJSON(json: any, fileName): void
Starts downloading of JSON data to a named file.
createTrustedUrl(blob: Blob): string
Creates a trusted URL to access the data in blob.
Details
Use the Content service to deliver data to the user from Blob objects.
The Blob class (implemented in the browser, not ADF) represents an array of bytes that you can use to construct and store data in any binary format you choose. The user can access a Blob either by downloading the byte array as a file or in some cases by viewing it directly in the browser via a special URL that references the Blob. For example, you could use the Blob interface to construct an image in the PNG format. Since PNG is a format the browser can display, you could use the Blob's URL in an <img> element to view the image within the page. Alternatively, you could let the user download it as a PNG file.
The downloadBlob method starts a download of the Blob data to the filename
within the user's downloads folder. The other downloadXXX methods do the same
but first convert the supplied data to a Blob before downloading; see the
Blob reference page
for details of how a Blob's contents are assembled from the constructor arguments.
Use createdTrustedUrl to generate a URL string for a Blob. The URL refers to
the Blob as though it were a file but it is actually an object stored in memory,
so it does not persist across browser sessions. This URL can be used much like any
other, so you could use it for the src attribute of an <img> element or the
href of a download link. Note that while the URL is 'trusted', the data it contains
is not necessarily trustworthy unless you can vouch for it yourself; be careful that
the data doesn't expose your app to
Cross Site Scripting
attacks.