Define ApiQuery::isWriteMode

Why:
* ApiQueryBase subclasses may define a ::isWriteMode override, as
  the API call may need to write to the DB.
** This is the case for the CheckUser extension, where the
   'checkuser' API creates a log entry that allows users to audit
   usage of the API.
* ApiQuery currently does not define a implementation of
  ::isWriteMode, which means that the definitions by any class
  that extends ApiQueryBase currently do nothing.
* ApiQuery::isWriteMode should be defined and work in a similar
  way to ApiQuery::isReadMode, so that subclasses of ApiQueryBase
  can have their definitions of ::isWriteMode respected.

What:
* Define ApiQuery::isWriteMode in a similar way to how ApiQuery
  ::isReadMode is written, but also inspecting the modules that
  are used through the 'list' and 'prop' params.
* Add tests for ApiQuery::isWriteMode.

Bug: T361951
Change-Id: Idf1c8f95df58a861404e0c89507c885ec4554793

1 files changed, 16 insertions, 0 deletions

diff --git a/includes/api/ApiQuery.php b/includes/api/ApiQuery.php
index b818f49a2dbe..7eff88de99b3 100644
--- a/includes/api/ApiQuery.php
+++ b/includes/api/ApiQuery.php
@@ -992,6 +992,22 @@ class ApiQuery extends ApiBase {
 		return false;
 	}
 
+	public function isWriteMode() {
+		// Ask each module if it requires write mode. If any require write mode this returns true.
+		$modules = [];
+		$this->mParams = $this->extractRequestParams();
+		$this->instantiateModules( $modules, 'list' );
+		$this->instantiateModules( $modules, 'meta' );
+		$this->instantiateModules( $modules, 'prop' );
+		foreach ( $modules as $module ) {
+			if ( $module->isWriteMode() ) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	protected function getExamplesMessages() {
 		$title = Title::newMainPage()->getPrefixedText();
 		$mp = rawurlencode( $title );