I got a script which takes several images from my MySQL database, which are stored as blobs. This script is accessed from a JavaScript / Ajax request.
So for now i display the blob in a div. But how can i convert the blob to an image in JavaScript?
1 Answer
First, you could expose the image data as resources on the server-side then instantiate an image node in your client-side with the src set the appropriate URL.
<img src="mydomain/images/my-resource.png" />
The resource mydomain/images/my-resource.png does not need to be a static resource on the server; the URL just needs to return the image data in an HTTP response.
Second, if you have the blob in base64 on the client-side already, use a data-url. Format (from Wikipedia):
data:[<MIME-type>][;charset=<encoding>][;base64],<data>
Example (from Wikpedia):
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA
AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
9TXL0Y4OHwAAAABJRU5ErkJggg==" alt="Red dot" />
If you actually have raw binary data on the client-side then the btoa function may be of use when constructing said data-url.
Finally, you could also use the HTML5 File API, performing an XMLHttpRequest, configured with a responseType of either 'blob', or 'arraybuffer'. You can then instantiate an in-memory URL for the object, and assign this to the src of an Image DOM node.
base64_encodefirst so it's valid Base64 when it's received.