Merge branch 'develop' into css-variables

# Conflicts:
#	demo/dist/demo.css
#	demo/dist/demo.js
#	demo/dist/demo.js.map
#	demo/dist/demo.min.js
#	demo/dist/demo.min.js.map
#	dist/plyr.css
#	dist/plyr.js
#	dist/plyr.js.map
#	dist/plyr.min.js
#	dist/plyr.min.js.map
#	dist/plyr.polyfilled.js
#	dist/plyr.polyfilled.js.map
#	dist/plyr.polyfilled.min.js
#	dist/plyr.polyfilled.min.js.map
#	gulpfile.js
#	src/sass/components/captions.scss
#	src/sass/components/control.scss

1 files changed, 76 insertions, 0 deletions

diff --git a/src/js/utils/loadSprite.js b/src/js/utils/loadSprite.js
new file mode 100644
index 00000000..917bd6ac
--- /dev/null
+++ b/src/js/utils/loadSprite.js
@@ -0,0 +1,76 @@
+// ==========================================================================
+// Sprite loader
+// ==========================================================================
+
+import Storage from '../storage';
+import fetch from './fetch';
+import is from './is';
+
+// Load an external SVG sprite
+export default function loadSprite(url, id) {
+    if (!is.string(url)) {
+        return;
+    }
+
+    const prefix = 'cache';
+    const hasId = is.string(id);
+    let isCached = false;
+
+    const exists = () => document.getElementById(id) !== null;
+
+    const update = (container, data) => {
+        container.innerHTML = data;
+
+        // Check again incase of race condition
+        if (hasId && exists()) {
+            return;
+        }
+
+        // Inject the SVG to the body
+        document.body.insertAdjacentElement('afterbegin', container);
+    };
+
+    // Only load once if ID set
+    if (!hasId || !exists()) {
+        const useStorage = Storage.supported;
+
+        // Create container
+        const container = document.createElement('div');
+        container.setAttribute('hidden', '');
+
+        if (hasId) {
+            container.setAttribute('id', id);
+        }
+
+        // Check in cache
+        if (useStorage) {
+            const cached = window.localStorage.getItem(`${prefix}-${id}`);
+            isCached = cached !== null;
+
+            if (isCached) {
+                const data = JSON.parse(cached);
+                update(container, data.content);
+            }
+        }
+
+        // Get the sprite
+        fetch(url)
+            .then(result => {
+                if (is.empty(result)) {
+                    return;
+                }
+
+                if (useStorage) {
+                    window.localStorage.setItem(
+                        `${prefix}-${id}`,
+                        JSON.stringify({
+                            content: result,
+                        }),
+                    );
+                }
+
+                update(container, result);
+            })
+            .catch(() => {});
+    }
+}