Support File Type Variables in LLM Node Prompt Editor with Automatic Format Conversion

[laipz8200]

Currently, Dify's LLM Node prompt editor does not support using File type variables directly. This enhancement would allow users to include File type variables directly in the prompt editor, where Dify automatically converts the file content into the correct format for the chosen model (e.g., text extraction for text-based models).

If a file type is unsupported by the model, Dify should raise an error. This feature would improve the flexibility of prompt creation and streamline workflows involving file data.

Acceptance Criteria

1. Users can include File type variables in the LLM Node prompt editor.
2. Dify should convert the file content to the appropriate format for the selected model.
3. If the file type is unsupported by the model, it should be ignored without causing errors.