Fix issue with previewing some challenge plugins (#1579)

CTFd/themes/admin/assets/js/pages/challenge.js

@@ -237,20 +237,27 @@ function handleChallengeOptions(event) {
 
 $(() => {
   $(".preview-challenge").click(function(_e) {
-    window.challenge = new Object();
     CTFd._internal.challenge = {};
     $.get(
       CTFd.config.urlRoot + "/api/v1/challenges/" + window.CHALLENGE_ID,
       function(response) {
-        const challenge = CTFd._internal.challenge;
+        // Preview should not show any solves
         var challenge_data = response.data;
         challenge_data["solves"] = null;
 
         $.getScript(
           CTFd.config.urlRoot + challenge_data.type_data.scripts.view,
           function() {
+            const challenge = CTFd._internal.challenge;
+
+            // Inject challenge data into the plugin
+            challenge.data = response.data;
+
             $("#challenge-window").empty();
 
+            // Call preRender function in plugin
+            challenge.preRender();
+
             $("#challenge-window").append(challenge_data.view);
 
             $("#challenge-window #challenge-input").addClass("form-control");