Fetch
The fetch module handles RAP file listing, file download helpers, and UKB metadata shortcuts. It is the lightweight access layer for files that already exist in the project.
Scope
| Function | Role |
|---|---|
fetch_ls() |
List files or folders on RAP |
fetch_tree() |
Display a recursive RAP folder tree |
fetch_url() |
Generate a pre-authenticated download URL |
fetch_file() |
Download RAP files to the current environment |
fetch_metadata() |
Download UKB metadata tables used by decoding |
fetch_field() |
Download field metadata shortcuts |
Workflow Role
Use fetch_metadata() before value decoding and use fetch_ls() or fetch_tree() to inspect RAP project structure. For data policy reasons, individual-level phenotype tables should normally stay in RAP; local download helpers should be used only for permitted files and summary-level outputs.
Review Focus
- path validation before calling
dx; - overwrite and resume behavior for downloads;
- metadata file naming and integrity checks;
- messages that make RAP paths and local destinations easy to audit.