targets_notes.qmd

---
title: "Targets Notes"
format: gfm
---

<!-- targets_notes.md is generated from targets_notes.qmd - edit that file -->

Notes about using the `targets` R package, focused on a few useful functions and options. For a comprehensive reference, see the {targets} user manual: <https://books.ropensci.org/targets/>

## visualize / validate the pipeline

-   view the network: `tar_visnetwork()`
-   see a list of the targets: `tar_manifest()`
-   view a simplified network (without functions): `tar_glimpse()`

## run pipeline / clear results

-   run the pipeline: `tar_make()`
-   invalidate a particular target, to force it to re-run (regardless of its actual state): `tar_invalidate()`
-   invalidate all targets to force the entire pipeline to re-run (note that this does not destroy the `_targets.R` file, just the outputs in the `_targets` folder): `tar_destroy()`

## inspect outputs

These functions allow you to view or load the output object from any target (e.g., a dataset). Before using any of these functions, make sure to load any packages required to use the given object/dataset (e.g., if the target object being retrieved is geospatial data, load the `sf` package - otherwise you'll get an error when you try to use that object):

-   read an object/target directly (don't load as a variable): `tar_read()`
-   load an object/target (as a variable in the global environment): `tar_load()`

## debugging / development

Use workspaces:

-   save a particular workspace: `tar_option_set(workspaces = c(...))`
-   save a workspace for any target that has an error: `tar_option_set(workspace_on_error = TRUE)`
-   to load a workspace, call: `tar_workspace(workspace_name)`
-   to see available workspaces, call: `tar_workspaces()`

## build reports / presentations

-   Quarto: `tarchetypes::tar_quarto()`
    -   embed target objects (e.g., plots) with `targets::tar_read(target_name)`
    -   may also want to include `store = here::here(tar_config_get('store')))` in the `targets::tar_read()` call - this should allow for manual rendering (i.e. without having to render using `tar_make()` each time) (might not be the best practice though?)
    -   make sure packages needed to render the document are included in the .qmd file itself (and not just called by `tar_option_set()` in the `_targets.R` file)
-   Rmarkdown: `tarchetypes::tar_render()`