Overview
Built-in Engines
Currently, NocoBase supports the following built-in engine types:
A local storage engine is automatically added during system installation and can be used directly. You can also add new engines or edit the parameters of existing ones.
Common Engine Parameters
In addition to the specific parameters for different engine types, the following are common parameters (using local storage as an example):

Title
The name of the storage engine, used for human identification.
System Name
The system name of the storage engine, used for system identification. It must be unique across the system. If left blank, it will be randomly generated by the system.
Access base URL
The prefix of the URL address for external access to the file. This can be the base URL of a CDN, for example: "https://cdn.nocobase.com/app" (without the trailing "/").
Path
The relative path used when storing files. This part will also be automatically concatenated to the final URL when accessed. For example: "user/avatar" (without the leading or trailing "/").
File Size Limit
The size limit for files uploaded to this storage engine. Files exceeding this size cannot be uploaded. The system default limit is 20MB, and the maximum adjustable limit is 1GB.
File Type
Limits the types of files that can be uploaded, using the MIME syntax description format. For example, image/* represents image files. Multiple types can be separated by commas, such as image/*, application/pdf to allow both image and PDF files.
Default Storage Engine
When checked, this is set as the system's default storage engine. When an attachment field or file collection does not specify a storage engine, uploaded files will be saved to the default storage engine. The default storage engine cannot be deleted.
Keep Files When Destroying Records
When checked, uploaded files in the storage engine are retained even when the data records in the attachment or file collection are deleted. By default, this is unchecked, meaning files in the storage engine are deleted along with the records.
After a file is uploaded, the final access path is constructed by concatenating several parts:
For example: https://cdn.nocobase.com/app/user/avatar/20240529115151.png.

