Make all macros used in a template's metrics filters available in its functions, too

refs #187

Author: Al2Klimov

doc/04-Templates.md

@@ -125,6 +125,10 @@ The metric in question can be referenced in the function call using the macro
 
     alias(color(scale($metric$, 1000), '#1a7dd7'), 'Round trip time (ms)')
 
+In addition you may utilize all other macros here as well:
+
+    alias(color(scale(divideSeries($metric$, $service_name_template$.perfdata.$disk$.max), 100), '#1a7dd7'), 'Used (%)')
+
 ## Template Example <a id="templates-example"></a>
 
 The configuration examples used in this document are borrowed from the template

library/Graphite/Graphing/Templates.php

@@ -199,17 +199,6 @@ function($option) {
                             );
                         }
 
-                        if ($curves[$curve][1]->getMacros() !== ['metric']) {
-                            throw new ConfigurationError(
-                                'Bad function "%s" for curve "%s" of template "%s" in file "%s":'
-                                . ' function definitions of templates must include the macro $metric$ and no other ones',
-                                $template['functions'][$curve],
-                                $curve,
-                                $templateName,
-                                $path
-                            );
-                        }
-
                         unset($template['functions'][$curve]);
                     } else {
                         $curves[$curve][1] = new MacroTemplate('$metric$');

library/Graphite/Web/Widget/GraphImage.php

@@ -84,10 +84,26 @@ public function render()
                 $params->set($key, $value->resolve($variables));
             }
 
-            foreach ($this->chart->getMetrics() as $curveName => $metric) {
-                $params->add('target', $template->getCurves()[$curveName][1]->resolve([
-                    'metric' => $graphiteWebClient->escapeMetricPath($metric)
-                ]));
+            $metrics = $this->chart->getMetrics();
+
+            foreach ($metrics as &$metric) {
+                $metric = $graphiteWebClient->escapeMetricPath($metric);
+            }
+            unset($metric);
+
+            $allVars = [];
+
+            foreach ($template->getCurves() as $curveName => $curve) {
+                $vars = $curve[0]->reverseResolve($metrics[$curveName]);
+
+                if ($vars !== false) {
+                    $allVars = array_merge($allVars, $vars);
+                }
+            }
+
+            foreach ($metrics as $curveName => $metric) {
+                $allVars['metric'] = $metric;
+                $params->add('target', $template->getCurves()[$curveName][1]->resolve($allVars));
             }
 
             $url = Url::fromPath('/render')->setParams($params);