From 176ee2bc9becdc7c6e6e03e9f06a826326e0952f Mon Sep 17 00:00:00 2001
From: Patrick Steele-Idem <pnidem@gmail.com>
Date: Tue, 2 Feb 2016 16:01:00 -0700
Subject: [PATCH] Marko v3: Added support for node.onBeforeGenerateCode and
 node.onAfterGenerateCode

---
 compiler/CodeGenerator.js | 40 +++++++++++++++++++++++++++++++++++++--
 compiler/ast/Node.js      | 33 ++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/compiler/CodeGenerator.js b/compiler/CodeGenerator.js
index 60481b8e2..dd33b56e7 100644
--- a/compiler/CodeGenerator.js
+++ b/compiler/CodeGenerator.js
@@ -9,6 +9,27 @@ const Container = require('./ast/Container');
 const util = require('util');
 const isValidJavaScriptIdentifier = require('./util/isValidJavaScriptIdentifier');
 
+class GeneratorEvent {
+    constructor(node, codegen) {
+        this.node = node;
+        this.codegen = codegen;
+
+        this.isBefore = true;
+        this.builder = codegen.builder;
+        this.context = codegen.context;
+    }
+
+    insertCode(newCode) {
+        this.codegen.generateStatements(newCode);
+
+        if (this.isBefore) {
+            if (!this.codegen._code.endsWith(this.codegen.currentIndent)) {
+                this.codegen.writeLineIndent();
+            }
+        }
+    }
+}
+
 class Slot {
     constructor(codegen, slotNode) {
         this._content = null;
@@ -80,7 +101,6 @@ class Generator {
 
         this._bufferedWrites = null;
         this.builder = context.builder;
-        this.walker = context.walker;
         this.outputType = options.output || 'html';
         this.context = context;
 
@@ -138,6 +158,17 @@ class Generator {
         let generateCodeFunc;
         var isStatement = node.statement;
 
+        var beforeAfterEvent;
+
+        if (node.listenerCount('beforeGenerateCode') || node.listenerCount('beforeGenerateCode')) {
+            beforeAfterEvent = new GeneratorEvent(node, this);
+        }
+
+        if (beforeAfterEvent) {
+            beforeAfterEvent.isBefore = true;
+            beforeAfterEvent.node.emit('beforeGenerateCode', beforeAfterEvent);
+        }
+
         if (node.getCodeGenerator) {
             generateCodeFunc = node.getCodeGenerator(this.outputType);
             if (generateCodeFunc) {
@@ -191,6 +222,11 @@ class Generator {
             }
         }
 
+        if (beforeAfterEvent) {
+            beforeAfterEvent.isBefore = false;
+            beforeAfterEvent.node.emit('afterGenerateCode', beforeAfterEvent);
+        }
+
         this._currentNode = oldCurrentNode;
     }
 
@@ -484,7 +520,7 @@ class Generator {
 
             this.decIndent();
             this.writeLineIndent();
-            this.write(']\n');
+            this.write(']');
         } else if (typeof value === 'number') {
             this.write(value.toString());
         } else if (typeof value === 'object') {
diff --git a/compiler/ast/Node.js b/compiler/ast/Node.js
index b38857ac7..a05de4deb 100644
--- a/compiler/ast/Node.js
+++ b/compiler/ast/Node.js
@@ -4,6 +4,7 @@ var ArrayContainer = require('./ArrayContainer');
 var ok = require('assert').ok;
 var extend = require('raptor-util/extend');
 var inspect = require('util').inspect;
+var EventEmitter = require('events').EventEmitter;
 
 class Node {
     constructor(type) {
@@ -16,9 +17,40 @@ class Node {
         this._flags = {};
         this._transformersApplied = {};
         this._preserveWhitespace = null;
+        this._events = null;
         this.data = {};
     }
 
+    on(event, listener) {
+        if (!this._events) {
+            this._events = new EventEmitter();
+        }
+
+        this._events.on(event, listener);
+    }
+
+    emit(event, args) {
+        if (this._events) {
+            this._events.emit.apply(this._events, arguments);
+        }
+    }
+
+    listenerCount(event) {
+        if (this._events) {
+            return this._events.listenerCount(event);
+        } else {
+            return 0;
+        }
+    }
+
+    onBeforeGenerateCode(listener) {
+        this.on('beforeGenerateCode', listener);
+    }
+
+    onAfterGenerateCode(listener) {
+        this.on('afterGenerateCode', listener);
+    }
+
     wrap(wrapperNode) {
         ok(this.container, 'Node does not belong to a container: ' + this);
         var replaced = this.container.replaceChild(wrapperNode, this);
@@ -81,6 +113,7 @@ class Node {
         delete result.data;
         delete result.tagDef;
         delete result._preserveWhitespace;
+        delete result._events;
         return result;
     }