From bbb3d55f6e0315faf03dcf894709cc04d6109179 Mon Sep 17 00:00:00 2001
From: Christian Mohr <christian.mohr@insitu.de>
Date: Wed, 7 Mar 2018 19:05:09 +0100
Subject: improved code structure and comments

---
 system/core/Loader.php | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

(limited to 'system/core/Loader.php')

diff --git a/system/core/Loader.php b/system/core/Loader.php
index 07e572950..18fba2b72 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -94,11 +94,11 @@ class CI_Loader {
 	protected $_ci_cached_vars =	array();
 
 	/**
-	 * stack of variables for nested _ci_load calls
+	 * Stack of variable arrays to provide nested _ci_load calls all variables from parent calls
 	 *
 	 * @var	array
 	 */
-	protected $_ci_vars_stack =	array();
+	protected $_ci_load_vars_stack =	array();
 
 	/**
 	 * List of loaded classes
@@ -945,26 +945,38 @@ class CI_Loader {
 		 *
 		 * You can either set variables using the dedicated $this->load->vars()
 		 * function or via the second parameter of this function. We'll merge
-		 * the two types. Additionally we merge them with the last variables
-		 * from the nested call stack so that views that are embedded within
-		 * other views can have access to these variables.
+		 * the two types so that loaded views and files have access to these
+		 * variables.
+		 * Additionally we want all subsequent nested _ci_load() calls embedded
+		 * within the current file to 'inherit' all variables that are
+		 * accessible to the current file. For this purpose we push the current
+		 * variable configuration (_ci_vars) to the stack and remove it again
+		 * after the file or view is completely loaded. Nested _ci_load() calls
+		 * within the current file extend the stack with their variable
+		 * configuration.
 		 */
 
-		// init current _ci_vars
+		// Init current _ci_vars as current variable configuration
 		if (!is_array($_ci_vars)) {
 			$_ci_vars = [];
 		}
 
-		// merge with global cached vars (first call) or last state from nested
-		// call stack (subsequent nested calls)
-		if (!empty($this->_ci_vars_stack)) {
-			$_ci_vars = array_merge(end($this->_ci_vars_stack), $_ci_vars);
-		} else if (!empty($this->_ci_cached_vars)) {
+		// Include the global cached vars into the current _ci_vars if needed
+		if (!empty($this->_ci_cached_vars)) {
 			$_ci_vars = array_merge($this->_ci_cached_vars, $_ci_vars);
 		}
 
-		// push current _ci_vars state to stack and extract it
-		array_push($this->_ci_vars_stack, $_ci_vars);
+		// Merge the last variable configuration from a parent _ci_load()
+		// call into the current _ci_vars
+		if (!empty($this->_ci_load_vars_stack)) {
+			$previous_variable_configuration = end($this->_ci_load_vars_stack);
+			$_ci_vars = array_merge($previous_variable_configuration, $_ci_vars);
+		}
+
+		// Push the current _ci_vars to the stack
+		array_push($this->_ci_load_vars_stack, $_ci_vars);
+
+		// Extract the current _ci_vars
 		extract($_ci_vars);
 
 		/**
@@ -983,8 +995,8 @@ class CI_Loader {
 		include($_ci_path); // include() vs include_once() allows for multiple views with the same name
 		log_message('info', 'File loaded: '.$_ci_path);
 
-		// remove current _ci_vars state from stack
-		array_pop($this->_ci_vars_stack);
+		// Remove current _ci_vars from stack again
+		array_pop($this->_ci_load_vars_stack);
 
 		// Return the file data if requested
 		if ($_ci_return === TRUE)
-- 
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