Configuration with options or environment variables
In qgisprocess: Use 'QGIS' Processing Algorithms

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

Options and environment variables are available to manage {qgisprocess} behaviour. Several options have a corresponding environment variable. When both have a value, the option will be given priority.

Options are typically harder to isolate from the R code that you collaborate on. Consequently, it is advised to:

use options() where this affects behaviour that must be the same across users and machines for reproducibility. Put these inside your script, or at least in a .Rprofile file that is shared together with the other project files.
use environment variables where behaviour must be machine-specific. For example, you can create a .Renviron file in your working directory and ignore it in distributed version control. Or you can set the environment variable at a higher level, e.g. in a .Renviron file in your home directory. See base::Startup for more information.

Overview

Below table lists the available options and environment variables.

Descriptions

Following descriptions are applicable to both option and environment variable:

qgisprocess.path: sets the path to 'qgis_process'; see qgis_configure()
qgisprocess.tmp_vector_ext: sets the vector file extension for temporary files; see qgis_tmp_vector()
qgisprocess.tmp_raster_ext: sets the raster file extension for temporary files; see qgis_tmp_raster()
qgisprocess.detect_newer_qgis: for Windows and macOS; will report availability of an installed (standalone) QGIS version that is more recent than the cached version
qgisprocess.use_json_input: control whether the JSON input method is used; see qgis_using_json_input()
qgisprocess.use_json_output: control whether the JSON output method is used; see qgis_using_json_output()
qgisprocess.cachefiles_days_keep: control a cache file's age (as days) that must be exceeded for it to be deleted when loading the package (default is 90); see ?qgis_delete_old_cachefiles
qgisprocess.use_cached_help: whether to fetch an algorithm's documentation from a cached file (corresponding to the QGIS and {qgisprocess} versions in use) if this file exists (default is TRUE; if FALSE, always (re)query documentation from QGIS)
qgisprocess.env: named list of environment variable values used in each call to 'qgis_process'; see qgis_run()