I am relatively new to web development and very new to using Web2py. The application I am currently working on is intended to take in a CSV upload from a user, then generate a PDF file based on the contents of the CSV, then allow the user to download that PDF. As part of this process I need to generate and access several intermediate files that are specific to each individual user (these files would be images, other pdfs, and some text files). I don't need to store these files in a database since they can be deleted after the session ends, but I am not sure the best way or place to store these files and keep them separate based on each session. I thought that maybe the subfolders in the sessions folder would make sense, but I do not know how to dynamically get the path to the correct folder for the current session. Any suggestions pointing me in the right direction are appreciated!
I was having this error "TypeError: expected string or Unicode object, NoneType found" and I had to store just a link in the session to the uploaded document in the db or maybe the upload folder in your case. I would store it to upload to proceed normally, and then clear out the values and the file if not 'approved'?
If the information is not confidential in similar circumstances, I directly write the temporary files under /tmp.
Related
I have to python files that create and read text from a .txt file, in order for them to work they need to know the info inside of the .txt file.
In heroku I have a scheduler that runs one file, then the other. The big problem is that the files are reset every time to their state from the original repo. How can I get around this?
Heroku does not offer a persistent file system. You will need to store them in another service (like S3), or depending on what the contents of your files are, redesign to write and read from a database instead.
I need a component that's a browser-based file browser, and I expect some django app to currently provide this. Is there such a thing?
The full story:
I'm building a django app that is used for testing. I want to use it to serve files (and strings, and etc.) and attach custom headers to it.
Currently, I have a model FileSource which has a single file_path field, which is of type django.db.models.FileField.
When creating a FileSource from the admin, the user has a nice file upload dialog, and when saving, the file he chose, is saved on the server (in a really weird location, inside the directory where django is installed, or something weird like that, because i didn't customize the storage, nor will it help me in any way)
My problem: I only want to use the file dialog for the user to select a full path on the server. The file that the user chose must be only referenced, not copied (like currently), and it must reside on the server.
The server must thus be able to list the files it has, so i basically need a little browser-based file-browser.
At that point, I expect to be able to save a full path in my DB, and then I'll be able to access that file and serve it (together with whatever custom headers the user will chose from my app).
Currently, as you might know, the browsers always lie about the full path of the file. Chromium appends "C:\fakepath" to the file name, so I need support of the backend to accomplish this.
Also, I checked out django-filebrowser and django-filer and from what I understood, they weren't built for this. If I'm wrong, a little assistence in configuring them would be awesome.
You can use a FilePathField for that. It won't upload a file, but rather allow you to choose a pre-existing file. A caveat is that you can only use one directory. If you need multiple directories, then you'd need do go with something like django-filer.
You can upload an individual file with the Admin site. However I have a need to upload at least 1 file, but potentially multiple files, for each object. Sometimes there will be sub-directories with these files that must also be uploaded.
Is there a good way to do this in the Admin site? Or would you recommend simply sftp-ing the files across and storing the path to them?
Thank you for your help.
I've only very recently starting working with Django, so do not yet know all the cool features I could be using :-)
Maybe have a look at https://github.com/stefanfoulis/django-filer, it allows multiple files to be uploaded at once.
I want to serve images in a web-app using sessions such that the links to the images expire once the session has expired.
If I show the actual links to the filesystem store of the images, say http://www.mywebapp.com/images/foo1.jpg this clearly makes stopping future requests for the image (one the user has signed out of the session) difficult to stop. Which is why I was considering placing the images in a sqlite db, and serving them from there.
It seems that using the db for image storage is considered bad practice (though apparently the GAE blob store seems to provide this functionality), so i was trying to figure out what the alternatives would be.
1)
Perhaps I do somesort of url-re-writing like so:
http://www.mywebapp.com/images/[session_id]/foo1.jpg
Thinking of using nginx, but it seems (on a first look) that this will require some hackin to accomplish?
2)
Copy the files to a physical directory on the filesystem and delete when the session expires. this seems quite messy though?
Are there any standard methods of accomplishing this dynamic image url thing?
I'm using web.py - if that helps.
Many thanks!
lighty's mod_secdownload has worked well for me to solve this issue. You can read more about it at http://redmine.lighttpd.net/wiki/1/Docs:ModSecDownload
The lighttpd wiki also has a generic article about your problem: http://redmine.lighttpd.net/wiki/1/HowToFightDeepLinking
Why so complicated?
Serve the image under the name which the user supplied (i.e. http://www.mywebapp.com/images/foo1.jpg)
Save the images in a directory using a UUID as name.
Create a map of file names to UUIDs in the session.
In the handler for /images/ look up the real file name in the map. Return 404 if no such entry exists. Otherwise serve the image.
When the session is closed, delete all files from the map.
In a cron job, delete all images that are older than one day.
This way, several users can upload the same image (same name), images get deleted as soon as possible or by the cron job (if the server crashes or something like that).
A combination of your two ideas (copy to a dir, expire when session expires) could be generalized to creating a new dir (could be as simple as a symlink) every 15 minutes. When generating the new symlink, also remove the one that's an hour old by now. Always link to the newest name in your code.
Is there a way to read the contents of a static data directory or interact with that data in any way from within the code of an application?
Edit: Please excuse me if it wasn't clear at first, I mean getting a list of the files in that directory, not reading the data in them.
No. Files marked as static in app.yaml are not available to your application; they're served from separate servers.
If you just need to list them, you could build a list as part of your deploy process. If you need to actually read them, you'll need to include a second copy in your application directory (although the "copy" can be just a symlink; appcfg.py will follow symlinks and upload them.)
You can just open them (only read only).