carrierwaveuploader/carrierwave
Carrierwave
CarrierWave is a Ruby file upload library used to manage the uploading, storing, and retrieval of files within web frameworks such as Rails and Sinatra. It functions as an Active Record file manager that associates uploaded assets with database records.
The project includes an image processing pipeline for generating thumbnails and derivative versions of uploaded images. It also features a file validation engine to restrict uploads based on allowlists or denylists of extensions and content types, and provides cloud storage integration to manage assets on remote providers.
The library covers broader capabilities including web form upload caching to persist files during validation failures, the ability to upload files via remote URLs, and the management of multiple file upload fields within a single record. It also supports the customization of filenames, storage paths, and the use of fallback URLs when no file is present.
Features
- File Upload Management - Handles the uploading, storing, and retrieval of files within Ruby web applications.
- Cloud Storage Integrations - Connects to external storage providers to save and retrieve files from remote cloud environments.
- Derivative Versions - Creates multiple derivative versions of a single uploaded file, such as thumbnails with specific dimensions.
- Asset-to-Record Mappings - Associates file metadata and storage paths directly with database records to manage ownership and retrieval.
- Cloud Storage Wrappers - Implements an abstraction layer that decouples the application from specific cloud storage provider APIs.
- Storage Abstractions - Standardises file interactions across different local and remote cloud providers using a common interface.
- Derivative Media Versions - Generates multiple scaled or formatted versions of uploaded images based on predefined processing rules.
- Image Processing - Manipulates uploaded images using processing libraries to perform resizing and format conversion.
- Image Processing Pipelines - Implements a processing pipeline for generating thumbnails and various derivative versions of uploaded images.
- File Type Validators - Restricts uploads by validating file extensions and MIME types against allowlists or denylists.
- Form Upload Caching - Stores uploaded files during validation failures so users do not have to re-upload them upon form redisplay.
- Hybrid Cloud Storage Configuration - Defines custom directories for storing uploaded files and temporary caches across local and cloud providers.
- Derivative Regeneration - Regenerates processed versions of a file from the original source after processing logic changes.
- File Storage Services - Overrides storage and cache directories to control where files are saved on the filesystem or cloud.
- URL-Based Uploads - Downloads files from remote internet locations and stores them locally or in the cloud.
- Remote URL Media Linking - Provides capabilities for downloading and storing files from user-specified remote URLs.
- Upload Lifecycle Callbacks - Provides event hooks that trigger custom logic at specific stages of the file upload process.
- Storage Filename Strategies - Overrides the default naming convention for uploaded files to implement specific naming logic.
- Form Upload Caching - Caches uploaded files during form submissions so they are not lost when model validations fail.
- Upload Caching - Persists uploaded files during form submission failures to avoid re-uploading after validation errors.
- File Upload - Flexible file upload solution for various web frameworks.
- File Handling - File upload management for Ruby frameworks.
- Media and Communication - Handles file uploads.
