BlobUtil

Check to see if the $_POST is completely broken in file upload Sometimes, if the maxUpload_SIZE is exceeded, it deletes all of $_POST and we lose our session.

Check to see if the $_POST is completely broken in file upload Sometimes, if the maxUpload_SIZE is exceeded, it deletes all of $_POST

Returns true if this is a good upload, an error string if not

Make sure the contents of this file are a PNG or JPEG

uploadToBlob - returns blob_id or false

Returns false for any number of failures, for better detail, use validateUpload() before calling this to do the actual upload.

isTestKey - Indicate if this is a key that is supposed to stay in blob_file

Legacy code - returns array [id, sha256]

Returns false for any number of failures, for better detail, use validateUpload() before calling this to do the actual upload.

Set the backref for a file entry

This is a soft foreign key in the frorm of:

table:column:value peer_submit::submit_id::2

This is uses when we want to link a blob to a record at an even finer level than context_id and link_id which is done by default.

When an application is doing a two-phase commit where it is uploading the file and then creating the record in the table that references the file (i.e. peer_submit in the above example), it can set the back ref to have a value of -1 to indicate that the file is as yet unlinked

peer_submit::submit_id::-1

and then once the peer_submit record is committed call this routine to point to the real record in the table.

Read a file off local disk and put it into a blob

Delete a blob based on its id

This cleans up files from the file table and if there are no more references to the file, eliminates the blob. This can only delete blobs in the current CONTEXT - but ultimately it is up to the calling code to decide who (i.e. an instructor) is allowed to delete a file.

Check and migrate a blob from an old place to the right new place

Check and migrate a blob from blob_file to blob_blob

Check and migrate a blob to its corresponding file