fix(index): dynamic css loading support for older browsers (#294)

Author: moyus

Diff for: src/index.js

@@ -379,6 +379,18 @@ class MiniCssExtractPlugin {
                     : '',
                   'var head = document.getElementsByTagName("head")[0];',
                   'head.appendChild(linkTag);',
+                  "// old webkit's would claim to have onload, but didn't really support it",
+                  '// https://github.com/kriszyp/xstyle/blob/master/core/load-css.js',
+                  'var webkitVersion = navigator.userAgent.match(/AppleWebKit\\/(\\d+\\.?\\d*)/);',
+                  'webkitVersion = webkitVersion && +webkitVersion[1];',
+                  'if (webkitVersion < 536) {',
+                  Template.indent([
+                    '// http://www.backalleycoder.com/2011/03/20/link-tag-css-stylesheet-load-event/',
+                    'var img = document.createElement("img");',
+                    'img.onerror = resolve;',
+                    `img.src = fullhref;`,
+                  ]),
+                  '}',
                 ]),
                 '}).then(function() {',
                 Template.indent(['installedCssChunks[chunkId] = 0;']),