Finally wait is over I mean after nearly a rough patch of virtually no post for an year I back with a post again
As the title suggest it with regards to some tips and tricks that I manage to pull on carrierwave when working on a project
A) Upload Simultaneously to File and S3
I know there are tons of way to do this like upload the file first to server and then using the background process upload it to
S3 blah blah .
Even directly upload to
S3 is also an options since
AMAZON S3 allow
CORS
Well all this work great but I kind of not want to do them perhaps, may try some other approach
(Mind you nothing against the other approach mention thus after or already exists)
So what is my approach well basically nothing all you have to do customize your uploader a bit (not heavy customization though )
Consider this is your standard uploader look like with default storage as
:file
class MyUploader < CarrierWave::Uploader::Base
storage :file
... blah ...
... blah ...
... blah ...
end
Now to simultaneously upload it to S3 all you have to do is place this in your
uploader.
version :s3_version do
storage :fog
def full_file_name
super.sub(/s3_version_/,'')
end
end
So your uploader finally look like this
class MyUploader < CarrierWave::Uploader::Base
storage :file
... blah ...
... blah ...
version :s3_version do
storage :fog
def full_file_name
super.sub(/s3_version_/,'')
end
end
end
That it define a version
:s3_version (virtually any name you want) and then use storage as
:fog in it (make sure to change the
REGULAR EXPRESSION incase you chose a different version name other then
s3_version)
Note : Also make sure to add the FOG setting for Carrierwave (S3 is just taken as an example it would work it all storage that fog provide)
Now most of you would argue that if say
S3 isn't responding/ something goes
wrong in
S3 over net, then your local storage goes for a toss and I agree completely with that to so I urge viewer to please take a note of this . Well for me I happy taking that risk on my part . :)
B). Delete the record but don't delete the attachment
Well not all would agree with me on this but there are time when we been ask to
delete the uploader record but
not delete the file stored :)
There could be many reason like in my case there was a requirement that we need to retain the original copy of the client registered agreement even though the client not longer exists
As said there exists even a dozen tons of ways to achieve this as well but let me show you how I manage to pull off this.
All I did is I overwrite the method
remove! in my
uploader and I also define a
attr_accessor against my model (i.e
attr_accessor :keep_file on my model)
Enough said time for code
class MyUploader < CarrierWave::Uploader::Base
def remove!
unless model.keep_file
super
end
end
end
Now to secure the storage file and only delete the record all I did is set
:keep_file => true and rest is taken care.
What I mean is record are destroyed but not the file from the storage system with this
There is another approach but I now tried and tested it that one would to overwrite the
remove?
method something like this (Note I haven't tested this )
class MyUploader < CarrierWave::Uploader::Base
def remove?
false
end
end
C). Custom the CarrierWave Error Message
Ever since I question/answered my own
question I'm seeing that I'm getting a lot of traction on it . What I have asked for is -
How to change the Carrierwave error message and set your own ?.
Well clearly the answer for that is define a key/value in your
en.yml for desired carrierwave error message and that it
e.g Let say
Carrierwave default message on extensions
whilelists valdations is this
You are not allowed to upload %{extension} files, allowed types: %{allowed_types}
Now want is to change reason (reason with held with me :) ) . So all I have to do is this
in my
en.yml define something like this
en:
errors:
messages:
extension_white_list_error: 'My Custom Message'
A full list of carrierwave key/value pair can be found over
here
That it guys hope you liked the tricks and found it useful
Thank You
