Caching an attached Excel file in a Ruby on Rails application typically involves using a combination of Rails' caching mechanisms and storage services. Here's a general guide on how to achieve this:
1. **Add the Attachment**:
Ensure you have a model in your Rails application that handles file attachments. You can use a gem like Paperclip, CarrierWave, ActiveStorage (built into Rails 5+), or any other attachment library. For example, with ActiveStorage, you can attach files to your model like this:
```ruby
class Report < ApplicationRecord
has_one_attached :excel_file
end
```
2. **Upload the Excel File**:
Your application should allow users to upload Excel files and attach them to a specific record.
3. **Enable Caching**:
Rails provides built-in caching support. You can configure caching by specifying the cache store in your `config/environments/production.rb` file. For example, to use file-based caching:
```ruby
config.cache_store = :file_store, "path/to/cache/directory"
```
4. **Cache the Excel File**:
When a user uploads an Excel file, you can cache it using Rails' caching mechanism. You can do this in your controller action. Here's an example:
```ruby
def cache_excel
report = Report.find(params[:id])
# Check if the file is already cached
if Rails.cache.exist?("cached_excel_#{report.id}")
cached_file = Rails.cache.read("cached_excel_#{report.id}")
else
# Cache the file if it's not already cached
cached_file = report.excel_file.download
Rails.cache.write("cached_excel_#{report.id}", cached_file, expires_in: 1.hour)
end
send_data cached_file, filename: "cached_excel.xlsx"
end
```
In this example, when a user requests the `cache_excel` action, the code checks if the file is already cached. If it's not, the file is downloaded from the attachment, cached, and then sent as a response.
5. **Cache Expiry and Cleanup**:
You may want to configure cache expiry and implement a cleanup mechanism to remove cached files after a certain period or when they are no longer needed.
6. **Security**:
Ensure that you have proper security measures in place to prevent unauthorized access to the cached files.
This is a basic example of how to cache an attached Excel file using Rails. The specifics may vary depending on your attachment library and your application's requirements.