From c7464ebf91af37482912b434a9e5dc25cf46666e Mon Sep 17 00:00:00 2001
From: Simon Brunel <simonbrunel@users.noreply.github.com>
Date: Sat, 2 Sep 2017 11:04:10 +0200
Subject: [PATCH] Add platform basic implementation (fallback) (#4708)

If `window` or `document` are `undefined`, a minimal platform implementation is used instead, which one only returns a context2d read from the given canvas/context.
---
 src/platforms/platform.basic.js | 15 +++++++++++++++
 src/platforms/platform.dom.js   |  7 +++++++
 src/platforms/platform.js       |  5 +++--
 3 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 src/platforms/platform.basic.js

diff --git a/src/platforms/platform.basic.js b/src/platforms/platform.basic.js
new file mode 100644
index 00000000000..f510b3575c7
--- /dev/null
+++ b/src/platforms/platform.basic.js
@@ -0,0 +1,15 @@
+/**
+ * Platform fallback implementation (minimal).
+ * @see https://github.com/chartjs/Chart.js/pull/4591#issuecomment-319575939
+ */
+
+module.exports = {
+	acquireContext: function(item) {
+		if (item && item.canvas) {
+			// Support for any object associated to a canvas (including a context2d)
+			item = item.canvas;
+		}
+
+		return item && item.getContext('2d') || null;
+	}
+};
diff --git a/src/platforms/platform.dom.js b/src/platforms/platform.dom.js
index 8fe9f27073c..a14119ad425 100644
--- a/src/platforms/platform.dom.js
+++ b/src/platforms/platform.dom.js
@@ -305,6 +305,13 @@ function injectCSS(platform, css) {
 }
 
 module.exports = {
+	/**
+	 * This property holds whether this platform is enabled for the current environment.
+	 * Currently used by platform.js to select the proper implementation.
+	 * @private
+	 */
+	_enabled: typeof window !== 'undefined' && typeof document !== 'undefined',
+
 	initialize: function() {
 		var keyframes = 'from{opacity:0.99}to{opacity:1}';
 
diff --git a/src/platforms/platform.js b/src/platforms/platform.js
index 8f4827732b1..c755f81fdb1 100644
--- a/src/platforms/platform.js
+++ b/src/platforms/platform.js
@@ -1,10 +1,11 @@
 'use strict';
 
 var helpers = require('../helpers/index');
+var basic = require('./platform.basic');
+var dom = require('./platform.dom');
 
-// By default, select the browser (DOM) platform.
 // @TODO Make possible to select another platform at build time.
-var implementation = require('./platform.dom');
+var implementation = dom._enabled ? dom : basic;
 
 /**
  * @namespace Chart.platform