handle_plugins(): only reconfigure package upon successful enabling/disabling

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: qgisprocess
 Title: Use 'QGIS' Processing Algorithms
-Version: 0.3.0.9001
+Version: 0.3.0.9002
 Authors@R: c(
     person("Dewey", "Dunnington", , "[email protected]", role = "aut",
            comment = c(ORCID = "0000-0002-9415-4582", affiliation = "Voltron Data")),

NEWS.md

@@ -3,8 +3,9 @@
 - Speed up various calls to the `qgis_process` backend by automatically implementing `--skip-loading-plugins` where possible (#201).
 This benefits package startup time and the timing of `qgis_run_algorithm()`, `qgis_show_help()`, and several other functions.
 This feature needs QGIS >= 3.36.
+- Don't renew the package cache when no plugins were successfully enabled or disabled (#212).
 - Update the 'getting started' vignette (#206, #207):
-  - advise using `qgis_search_algorithms()`.
+  - advise to use `qgis_search_algorithms()`.
   - in QGIS >= 3.36 the GRASS GIS provider is called `grass` instead of `grass7`.
 
 # qgisprocess 0.3.0

R/qgis-plugins.R

@@ -221,11 +221,20 @@ handle_plugins <- function(names = NULL, quiet = FALSE, mode) {
     "{paste(names, collapse = ', ')}"
   ))
 
-  if (mode == "enable") for (p in names) enable_plugin(p, quiet = quiet)
-  if (mode == "disable") for (p in names) disable_plugin(p, quiet = quiet)
+  counter <- 0L
+  if (mode == "enable") for (p in names) {
+    counter <- enable_plugin(p, quiet = quiet) + counter
+  }
+  if (mode == "disable") for (p in names) {
+    counter <- disable_plugin(p, quiet = quiet) + counter
+  }
 
-  if (!quiet) message("\nRebuilding cache to reflect current plugin state ...\n")
-  qgis_configure(use_cached_data = FALSE, quiet = quiet)
+  if (counter > 0L) {
+    if (!quiet) {
+      message("\nRebuilding cache to reflect current plugin state ...\n")
+    }
+    qgis_configure(use_cached_data = FALSE, quiet = quiet)
+  }
 
   invisible(qgis_plugins())
 }
@@ -234,6 +243,7 @@ handle_plugins <- function(names = NULL, quiet = FALSE, mode) {
 
 #' @keywords internal
 enable_plugin <- function(name, quiet = FALSE) {
+  error_detected <- FALSE
   tryCatch(
     {
       qgis_run(args = c("plugins", "enable", name))
@@ -244,14 +254,17 @@ enable_plugin <- function(name, quiet = FALSE) {
         "'{name}' was not successfully enabled. Error message was:\n\n{e}\n",
         ifelse("stderr" %in% names(e) && nchar(e$stderr) > 0, e$stderr, "")
       ))
+      assign("error_detected", TRUE, envir = parent.env(environment()))
     }
   )
+  if (error_detected) invisible(FALSE) else invisible(TRUE)
 }
 
 
 
 #' @keywords internal
 disable_plugin <- function(name, quiet = FALSE) {
+  error_detected <- FALSE
   tryCatch(
     {
       qgis_run(args = c("plugins", "disable", name))
@@ -262,6 +275,8 @@ disable_plugin <- function(name, quiet = FALSE) {
         "'{name}' was not successfully disabled. Error message was:\n\n{e}\n",
         ifelse("stderr" %in% names(e) && nchar(e$stderr) > 0, e$stderr, "")
       ))
+      assign("error_detected", TRUE, envir = parent.env(environment()))
     }
   )
+  if (error_detected) invisible(FALSE) else invisible(TRUE)
 }