I'm planning to build a Rails app where user can view content of zip-file in their browser without downloading the actual content. Is this possible using RubyonRails? Please guide me a way forward.
Thanks,
Sure you can! Take at look at the rubyzip gem. With it, you could for example get the names of all files contained in the zip as follows
zip_filenames = Zip::File.open('foo.zip') do |zip_file|
zip_file.map { |entry| entry.name }
end
Then use this array to somehow display it in your application. If you'd actually want to open a video/text file contained in the archive, you'll have to extract it on the server to some temporary location, then open it through some other means.
Related
I have a field to upload a file to my form. Now I want to be able to view it without downloading the file (it's a photo and no editing of the file is required). When I do download the file I would like to have it keep its original name instead of being renamed to a generic name (ex. original_name.* stays original_name.* instead of becoming serial_number_22.*).
I have the following.
In my .py file:
'file_upload' : fields.binary('Sales Contract'),
In my .xml file:
<field name="file_upload"/>
With kind regards,
Please have a look at this module Document Management System. This helps you in uploading and associating files to individual records. And separately under knowledge menu you can organize, view, share files and folders and sharing via ftp is also an additional option.
I am sorry if your purpose is different. I thought this may help you.
If it's an image, you can use widget="image" to view it directly after upload.
I got an app I'm working on that uses static data from a sqlite database to do various things, While I only need read only access to the database, depending on the episode they pick from the first screen I want it to use a different database file and I want the list of available episodes to be updateable on the fly. and I got help to get the list of available episodes updated, and the proper content downloaded and stored in separate folders, So I know I could when the episode is selected delete the sql file in the documents folder and copy in the new one each time and that would work well enough for what I'm trying to do. but it seems like a bit much extra work to have to check for file, delete file, copy in new one. then open it from there each time the user wants to pick a different episode. and I don't want to put all the sql files together as that will be a bigger hassle then the first route especially if this app stays around long enough to have a long list of episodes.
so my question here is: can I get at least read-only access to an sql file that I've downloaded (or one in the bundle for testing) with out having to first copy it to the documents? and if so how would i open the file?
Can I get at least read-only access to an SQL file that I've downloaded (or one in the bundle for testing) without having to first copy it to the documents directory?
Yes. Files in the app bundle are readable (if they weren't, there would be no point in storing files in the bundle).
And if so, how would I open the file?
It's not clear what you're asking here - if you want to perform SQL queries on the file, you should use the sqlite3 library which is available on iOS.
I have used paperclip to allow me to upload files to a rails application. Everything works and the file is uploaded, but instead of seeing a link to the actual file itself I see the location of it within the systems folder of the rails project.
I'm guessing its either a routing issue or I need to create a link to the file in question. However, I would like to hide the location of the file itself, and only see the link displayed.
I would be very grateful if someone could point me in the right direction here.
You want to hide the actual path of the file in the server, right?
You can achieve that using send_file (http://api.rubyonrails.org/classes/ActionController/DataStreaming.html#method-i-send_file) in a normal controller.
You will still need to do something to protect the download using the real path.
Does anyone have some sample code demonstrating how to make a "file browser" view? I'd like to be able to navigate through directories and drill-down the sub-directories and see files located within the various folders. I want the user to be able to create new directories/files and even select an existing file. Is there sample code out there already available to do this?
I don't know about sample code, but this wouldn't be too complicated to achieve using NSFileManager and a UITableView.
You can obtain arrays of directory contents using the subpathsOfDirectoryAtPath:error and associated methods of a file manager. These arrays in turn can populate a UITableView. It would be fairly easy to put together a navigation controller that could display a series of table views showing a file hiearchy.
Bear in mind, however, that you'll only be able to access the directories inside your application sandbox, unless you're running on a jailbroken device.
The iOS programming guide says that
You should never present users with the list of files in this directory and ask them to decide what to do with those files. Instead, sort through the files programmatically and add files without prompting.
This is assuming you are trying to implement file browse feature for your documents directory.
I'm an author of FileExplorer which is a file browser for iOS and fulfills most of your requirements.
Here are some of the features of my control:
Possibility to choose files or/and directories if there is a need for that
Possiblity to remove files or/and directories if there is a need for that
Built-in search functionality
View Audio, Video, Image and PDF files.
Possibility to add support for any file type.
You can find my control here.
I have a website that shows galleries. Users can upload their own content from the web (by entering a URL) or by uploading a picture from their computer.
I am storing the URL in the database which works fine for the first use case but I need to figure out where to store the actual images if a user does a upload from their computer.
Is there any recommendation here or best practice on where I should store these?
Should I save them in the appdata or content folders? Should they not be stored with the website at all because it's user content?
You should NOT store the user uploads anywhere they can be directly accessed by a known URL within your site structure. This is a security risk as users could upload .htm file and .js files. Even a file with the correct extension can contain malicious code that can be executed in the context of your site by an authenticated user allowing server-side or client-side attacks.
See for example http://www.acunetix.com/websitesecurity/upload-forms-threat.htm and What security issues appear when users can upload their own files? which mention some of the issues you need to be aware of before you allow users to upload files and then present them for download within your site.
Don't put the files within your normal web site directory structure
Don't use the original file name the user gave you. You can add a content disposition header with the original file name so they can download it again as the same file name but the path and file name on the server shouldn't be something the user can influence.
Don't trust image files - resize them and offer only the resized version for subsequent download
Don't trust mime types or file extensions, open the file and manipulate it to make sure it's what it claims to be.
Limit the upload size and time.
Depending on the resources you have to implement something like this, it is extremely beneficial to store all this stuff in Amazon S3.
Once you get the upload you simply push it over to Amazon and pop the URL in your database as you're doing with the other images. As mentioned above it would probably be wise to open up the image and resize it before sending it over. This both checks it is actually an image and makes sure you don't accidentally present a full camera resolution image to an end user.
Doing this now will make it much, much easier if you ever have to migrate/failover your site and don't want to sync gigabytes of image assets.
One way is to store the image in a database table with a varbinary field.
Another way would be to store the image in the App_Data folder, and create a subfolder for each user (~/App_Data/[userid]/myImage.png).
For both approaches you'd need to create a separate action method that makes it possible to access the images.
While uploading images you need to verify the content of the file before uploading it. The file extension method is not trustable.
Use magic number method to verify the file content which will be an easy way.
See the stackoverflow post and see the list of magic numbers
One way of saving the file is converting it to binary format and save in our database and next method is using App_Data folder.
The storage option is based on your requirement. See this post also
Set upload limit by setting maxRequestLength property to Web.Config like this, where the size of file is specified in KB
<httpRuntime maxRequestLength="51200" executionTimeout="3600" />
You can save your trusted data just in parallel of htdocs/www folder so that any user can not access that folder. Also you can add .htaccess authentication on your trusted data (for .htaccess you should kept your .htpasswd file in parallel of htdocs/www folder) if you are using apache.