Fix #1318: Configure PDFjs viewer for IE11 pdf preview

CHANGE.md

@@ -5,6 +5,7 @@ Change Log: `bootstrap-fileinput`
 
 **Date:** _under development_
 
+- (enh #1318): Configure PDFjs viewer for IE11 pdf preview.
 - (enh #1311): Correct preview zoom modal keydown next and prev keyboard behavior.
 - (enh #1308): Enhance audio file preview thumbnail styling.
 - (enh #1298): New `encodeUrl` boolean option that encodes all URL passed by default.

js/fileinput.js

@@ -4476,7 +4476,8 @@
             close: 'Close detailed preview'
         },
         usePdfRenderer: function () {
-            return !!navigator.userAgent.match(/(iPod|iPhone|iPad|Android)/i);
+            var isIE11 = !!window.MSInputMethodContext && !!document.documentMode;
+            return !!navigator.userAgent.match(/(iPod|iPhone|iPad|Android)/i) || isIE11;
         },
         pdfRendererUrl: '',
         pdfRendererTemplate: '<iframe class="kv-preview-data file-preview-pdf" src="{renderer}?file={data}" {style}></iframe>'