I have an image in blob store which is uploaded by users(their profile pic). I want to make a copy of the same and and re-size the copy so that it can be displayed as a thumbnail. I want to make a copy of the same instead of using the ImageService because this would be used more often compared to the profile image.
What I am doing here is this:
reader = profile_image.open() #get binary data from blob
data = reader.read()
file_name = files.blobstore.create(mime_type=profile_image.content_type)#file to write to
with files.open(file_name, 'a') as f:
f.write(data)
files.finalize(file_name)
blob_key = files.blobstore.get_blob_key(file_name)
image = images.Image(blob_key = blob_key)
image.resize(width=32, height=32)
entity.small_profile_pic = <MyImageModel>(caption=<caption given by user>,
picture=str(blob_key))
This is giving me error:
BadValueError: Image instance must have a complete key before it can be stored as a reference.
I think this is because the blob is not saved(put()) into the datastore, but how do i do it. Doed files.blobstore.get_blob_key(file_name) not do it ?
I would also like to ask: does the blobstore also cache the dynamically transformed images images served using get_serving_url() ...
I would use the get_serving_url method. In the doc is stated that:
The get_serving_url() method allows you to generate a stable, dedicated URL for serving web-suitable image thumbnails. You simply store a single copy of your original image in Blobstore, and then request a high-performance per-image URL. This special URL can serve that image resized and/or cropped automatically, and serving from this URL does not incur any CPU or dynamic serving load on your application (though bandwidth is still charged as usual). Images are served with low latency from a highly optimized, cookieless infrastructure.
Also the code you posted doesn't seem to follow the exampled posted in the docs. I would use something like this
img = images.Image(blob_key=original_image_key)
img.resize(width=32, height=32)
thumbnail = img.execute_transforms(output_encoding=images.JPEG)
file_name = files.blobstore.create(mime_type='image/jpeg')#file to write to
with files.open(file_name, 'a') as f:
f.write(thumbnail)
files.finalize(file_name)
blob_key = files.blobstore.get_blob_key(file_name)
Related
I am aiming to take a file a user attaches through an Lightning Component and create a document object containing the data.
So far I have overcome the request size limits by chunking the data being uploaded into 1MB chunks. When the Apex Aura method receives these chunks of data it will either create a new document (if it is the first chunk), or will retrieve the existing document and add the new chunk to the end.
Data is received Base64 encoded, and then decoded server-side.
As the document data is stored as a Blob, the original file contents will be read as a String, and then appended with the chunk received. The new contents are then converted back into a Blob to be stored within the ContentVersion object.
The problem I'm having is that strings in Apex have a maximum length of 6,000,000 or so. Whenever the file size exceeds 6MB, this limit is hit during the concatenation, and will cause the file upload to halt.
I have attempted to avoid this limit by converting the Blob to a String only when necessary for the concatenation (as suggested here https://developer.salesforce.com/forums/?id=906F00000008w9hIAA) but this hasn't worked. I'm guessing it was patched because it's still technically allocating a string larger then the limit.
Code's really simple when appending so far:
ContentVersion originalDocument = [SELECT Id, VersionData FROM ContentVersion WHERE Id =: <existing_file_id> LIMIT 1];
Blob originalData = originalDocument.VersionData;
Blob appendedData = EncodingUtil.base64Decode(<base_64_data_input>);
Blob newData = Blob.valueOf(originalData.toString() + appendedData.toString());
originalDocument.VersionData = newData;
You will have hard time with it.
You could try offloading the concatenation to asynchronous process (#future/Queueable/Schedulable/Batchable), they'll have 12MB RAM instead of 6. Could buy you some time.
You could try cheating by embedding an iframe (Visualforce or lightning:container tag? Or maybe a "canvas app") that would grab your file and do some manual JavaScript magic calling normal REST API for document upload: https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/dome_sobject_insert_update_blob.htm (last code snippet is about multiple documents). Maybe jsforce?
Can you upload it somewhere else (SharePoint? Heroku?) and have that system call into SF to push them (no Apex = no heap size limit). Or even look "Files Connect" up.
Can you send an email with attachments? Crude but if you write custom Email-to-Case handler class you'll have 36 MB of RAM.
You wrote "we needed multiple files to be uploaded and the multi-file-upload component provided doesn't support all extensions". That may be caused by these:
In Experience Builder sites, the file size limits and types allowed follow the settings determined by site file moderation.
lightning-file-upload doesn't support uploading multiple files at once on Android devices.
if the Don't allow HTML uploads as attachments or document records security setting is enabled for your organization, the file uploader cannot be used to upload files with the following file extensions: .htm, .html, .htt, .htx, .mhtm, .mhtml, .shtm, .shtml, .acgi, .svg.
I have an image that I loaded by using URLImage class. Here is the code:
EncodedImage placeholder = EncodedImage.createFromImage(Image.createImage(getWidth()/2, getWidth()/2 , 0xF92D2D), true);
Image originImg = URLImage.createToStorage(placeholder, imgFileName, photo_url);
To my understanding, this image is being saved into Storage with createToStorage() method. However, next time when I am loading this form, I don't want to download the image again, I want to take it from the Storage, because its faster.
So what I did, I added check :
if (Storage.getInstance().exists(imgFileName)) {
// Take the image from the Storage
originImg = Image.createImage(Storage.getInstance().createInputStream(imgFileName));
} else {
// Load the image with URLImage class.
}
However, it seems like my file is never saved into the Storage. What can be wrong?
You don't need to do that. URLImage seamlessly loads the file from storage if the file is already there. You can open the network monitor and see if a request is made to the URL for this specific image.
I'm not sure why the Storage.getInstance().exists(imgFileName) method would fail. I assume the image name is different in the different execution or something of that sort. You can see that images are created in your .cn1 directory.
I'm converting my site over to using the blobstore for image serving and am having a problem. I have a page with a large number of images being rendered dynamically (through jinja), and the only data available are entity keys that point to image objects that contain the relevant serving url.
Previously each image had a url along the lines of "/show-image?key={{image_key}}", which points to a request handler along the lines of this:
def get(self):
imageInfo = db.get(self.request.args.get("key"))
imagedata = imageInfo.data // the image is stored as a blob in the normal datastore
response = Response()
response.data = imagedata
response.headers['Content-Type'] = imageInfo.type
return response
My question is: How can I modify this so that, rather than returning a response with imageInfo.data, I return a response with imageInfo.saved_serving_url (generated from get_serving_url when the image object was created). More importantly, is this even a good idea? It seems like converting the saved_serving_url back into data (eg using urllib.fetch) might just counteract the speed and efficiency of using the high-speed datastore in the first place?
Maybe I should just rewrite my code so that the jinja template has direct access to the serving urls of each image. But ideally I'd like to avoid that due to the amount of parallel lists I'd have to pass about.
why not returning the serving url instead of the imagedata?
<img src="/show-image?key={{image_key}}" />
def get(self):
imageInfo = db.get(self.request.args.get("key"))
return imageInfo.saved_serving_url
I'm uploading some images to GAE's Blobstore. Upload goes succesfully and when i see the images in GAE console i can see that they're stored in the expected size and resolution.
According to this site, to get a URL to the uploaded image i can use this:
BlobKey blobKey = (BlobKey) blobs.get("image");
ImagesService imagesService = ImagesServiceFactory.getImagesService();
String imageUrl = imagesService.getServingUrl(blobKey);
The resulting URL points to a smaller version of the uploaded images (in size and quality). How can i get a URL to the full size image stored in Blobstore?
you can append =s0 parameter after the url to get full sized image.
I'd like to use GAE to allow a few users to upload files and later retrieve them. Files will be relatively small (a few hundred KB), so just storing stuff as a blob should work. I haven't been able to find any examples of something like this. There are a few image uploading examples out there but I'd like to be able to store word documents, pdfs, tiffs, etc. Any ideas/pointers/links? Thanks!
The same logic used for image uploads apply for other archive types. To make the file downloadable, you add a Content-Disposition header so the user is prompted to download it. A webapp simple example:
class DownloadHandler(webapp.RequestHandler):
def get(self, file_id):
# Files is a model.
f = Files.get_by_id(file_id)
if not f:
return self.error(404)
# Set headers to prompt for download.
headers = self.response.headers
headers['Content-Type'] = f.content_type or 'application/octet-stream'
headers['Content-Disposition'] = 'attachment; filename="%s"' % f.filename
# Add the file contents to the response.
self.response.out.write(f.contents)
(untested code, but you get the idea :)
It sounds like you want to use the Blobstore API.
You don't mention if you are using Python or Java so here are links to both.
I use blobstore API that admits any file upload/download up to 50 MB.