From 58c2d2bf5aa7a237a5490ff35da1b958427fe71c Mon Sep 17 00:00:00 2001
From: Jaifroid <egk10@cam.ac.uk>
Date: Mon, 14 Jan 2019 06:30:57 +0000
Subject: [PATCH] Add active content warning

---
 www/css/app.css      | 12 ++++++++++
 www/index.html       | 23 +++++++++++++++++--
 www/js/app.js        | 53 +++++++++++++++++++++++++++++++++++++++-----
 www/js/lib/uiUtil.js | 38 ++++++++++++++++++++++++++++++-
 4 files changed, 118 insertions(+), 8 deletions(-)

diff --git a/www/css/app.css b/www/css/app.css
index 728ec900b..8a1d1b28d 100644
--- a/www/css/app.css
+++ b/www/css/app.css
@@ -124,6 +124,18 @@
     width: 200px;
 }
 
+.alert {
+    margin-bottom: 0 !important;
+}
+
+.alert-link {
+    text-decoration: underline;
+}
+
+#alertBoxHeader {
+    text-align: center;
+}
+
 @keyframes spin {
     0% { transform: rotate(0deg); }
     100% { transform: rotate(360deg); }
diff --git a/www/index.html b/www/index.html
index 3550726bc..47db22f5f 100644
--- a/www/index.html
+++ b/www/index.html
@@ -202,7 +202,8 @@ <h2>Configuration</h2>
                                 <div id="openLocalFiles" style="display: none;">
                                     Please select the .zim file (or all the .zimaa, .zimab etc in case of a split ZIM file)<br />
                                     <input type="file" id="archiveFiles" multiple class="btn" accept=".zim,.dat,.idx,.txt,.zimaa,.zimab,.zimac,.zimad,.zimae,.zimaf,.zimag,.zimah,.zimai,.zimaj,.zimak,.zimal,.zimam,.ziman,.zimao,.zimap,.zimaq,.zimar,.zimas,.zimat,.zimau,.zimav,.zimaw,.zimax,.zimay,.zimaz,.zimba,.zimbb,.zimbc,.zimbd,.zimbe,.zimbf,.zimbg,.zimbh,.zimbi,.zimbj,.zimbk,.zimbl,.zimbm,.zimbn,.zimbo,.zimbp,.zimbq,.zimbr,.zimbs,.zimbt,.zimbu,.zimbv,.zimbw,.zimbx,.zimby,.zimbz" /><br />
-                                    <strong>Only Mediawiki-based (wiki*.zim* files, like wikipedia) and StackExchange contents have been tested</strong> for now. Audio/video/dynamic contents are not supported for now.<br />
+                                    <strong>Only Mediawiki-based (wiki*.zim* files, like wikipedia), StackExchange and some video-based ZIMs (e.g. TEDx) have been tested</strong>.
+                                    Dynamic content is not currently supported in jQuery mode.<br />
                                 </div>
                                 <div id="scanningForArchives" style="display: none;">
                                     <br /> Scanning for archives... Please wait <img src="img/spinner.gif" alt="Please wait..." />
@@ -216,6 +217,22 @@ <h2>Configuration</h2>
                     </div>
 
                     <div class="container">
+                        <div class="row">
+                            <h3>Display settings</h3>
+                            <div class="column">
+                                <div class="panel panel-info" id="displaySettingsDiv">
+                                    <div class="panel-heading">Display options:</div>
+                                    <div class="panel-body">
+                                        <div class="checkbox">
+                                            <label>
+                                                <input type="checkbox" name="hideActiveContentWarning" id="hideActiveContentWarningCheck">
+                                                <strong>Permanently hide active content warning</strong> (for experienced users)
+                                            </label>
+                                        </div>
+                                    </div>
+                                </div>
+                            </div>
+                        </div>
                         <div class="row">
                             <h3>Expert settings</h3>
                             <div class="column">
@@ -236,7 +253,7 @@ <h3>Expert settings</h3>
                                         </div>
                                     </div>
                                 </div>
-                                <div class="panel panel-info" id="apiStatusDiv">
+                                <div class="panel panel-warning" id="apiStatusDiv">
                                     <div class="panel-heading">API Status</div>
                                     <div class="panel-body">
                                         <div id="serviceWorkerStatus"></div>
@@ -261,6 +278,8 @@ <h3>Expert settings</h3>
                     <div id="articleList" class="list-group">
                     </div>
                 </div>
+                <!-- Bootstrap alert box -->
+                <div id="alertBoxHeader"></div>
                 <iframe id="articleContent" class="articleIFrame" src="article.html"></iframe>
             </article>
             <footer>
diff --git a/www/js/app.js b/www/js/app.js
index 63279065f..7919df9c6 100644
--- a/www/js/app.js
+++ b/www/js/app.js
@@ -49,6 +49,18 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
      */
     var selectedArchive = null;
     
+    /**
+     * A global parameter object for storing variables that need to be remembered between page loads
+     * or across different functions
+     * 
+     * @type Object
+     */
+    var params = {};
+
+    // Set parameters and associated UI elements from cookie
+    params['hideActiveContentWarning'] = cookies.getItem('hideActiveContentWarning') === 'true';
+    document.getElementById('hideActiveContentWarningCheck').checked = params.hideActiveContentWarning;
+    
     /**
      * Resize the IFrame height, so that it fills the whole available height in the window
      */
@@ -159,6 +171,7 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
         $('#articleListWithHeader').hide();
         $("#searchingArticles").hide();
         $('#articleContent').hide();
+        $('.alert').hide();
         refreshAPIStatus();
         return false;
     });
@@ -178,22 +191,31 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
         $('#articleListWithHeader').hide();
         $("#searchingArticles").hide();
         $('#articleContent').hide();
+        $('.alert').hide();
         return false;
     });
     $('input:radio[name=contentInjectionMode]').on('change', function(e) {
         // Do the necessary to enable or disable the Service Worker
         setContentInjectionMode(this.value);
     });
-    
+    $('input:checkbox[name=hideActiveContentWarning]').on('change', function (e) {
+        params.hideActiveContentWarning = this.checked ? true : false;
+        cookies.setItem('hideActiveContentWarning', params.hideActiveContentWarning, Infinity);
+    });
+
     /**
      * Displays of refreshes the API status shown to the user
      */
     function refreshAPIStatus() {
+        var apiStatusPanel = document.getElementById('apiStatusDiv');
+        apiStatusPanel.classList.remove('panel-success', 'panel-warning');
+        var apiPanelClass = 'panel-success';
         if (isMessageChannelAvailable()) {
             $('#messageChannelStatus').html("MessageChannel API available");
             $('#messageChannelStatus').removeClass("apiAvailable apiUnavailable")
                     .addClass("apiAvailable");
         } else {
+            apiPanelClass = 'panel-warning';
             $('#messageChannelStatus').html("MessageChannel API unavailable");
             $('#messageChannelStatus').removeClass("apiAvailable apiUnavailable")
                     .addClass("apiUnavailable");
@@ -204,15 +226,19 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
                 $('#serviceWorkerStatus').removeClass("apiAvailable apiUnavailable")
                         .addClass("apiAvailable");
             } else {
+                apiPanelClass = 'panel-warning';
                 $('#serviceWorkerStatus').html("ServiceWorker API available, but not registered");
                 $('#serviceWorkerStatus').removeClass("apiAvailable apiUnavailable")
                         .addClass("apiUnavailable");
             }
         } else {
+            apiPanelClass = 'panel-warning';
             $('#serviceWorkerStatus').html("ServiceWorker API unavailable");
             $('#serviceWorkerStatus').removeClass("apiAvailable apiUnavailable")
                     .addClass("apiUnavailable");
         }
+        apiStatusPanel.classList.add(apiPanelClass);
+
     }
     
     var contentInjectionMode;
@@ -640,6 +666,7 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
      */
     function searchDirEntriesFromPrefix(prefix) {
         if (selectedArchive !== null && selectedArchive.isReady()) {
+            $('#activeContent').alert('close');
             selectedArchive.findDirEntriesWithPrefix(prefix.trim(), MAX_SEARCH_RESULT_SIZE, populateListOfArticles);
         } else {
             $('#searchingArticles').hide();
@@ -713,12 +740,11 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
             $("#searchingArticles").show();
             if (dirEntry.isRedirect()) {
                 selectedArchive.resolveRedirect(dirEntry, readArticle);
-            }
-            else {
+            } else {
+                params.isLandingPage = false;
                 readArticle(dirEntry);
             }
-        }
-        else {
+        } else {
             alert("Data files not set");
         }
     }
@@ -823,6 +849,13 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
     // remove any relative or absolute path from ZIM-style URLs.
     // DEV: If you want to support more namespaces, add them to the END of the character set [-IJ] (not to the beginning) 
     var regexpTagsWithZimUrl = /(<(?:img|script|link|video|audio|source|track)\b[^>]*?\s)(?:src|href)(\s*=\s*["'])(?:\.\.\/|\/)+(?=[-IJ]\/)/ig;
+    // Regex below tests the html of an article for active content [kiwix-js #466]
+    // It inspects every <script> block in the html and matches in the following cases: 1) the script loads a UI application called app.js;
+    // 2) the script block has inline content that does not contain "importScript()" or "toggleOpenSection" (these strings are used widely
+    // in our fully supported wikimedia ZIMs, so they are excluded); 3) the script block is not of type "math" (these are MathJax markup
+    // scripts used extensively in Stackexchange ZIMs). Note that the regex will match ReactJS <script type="text/html"> markup, which is
+    // common in unsupported packaged UIs, e.g. PhET ZIMs.
+    var regexpActiveContent = /<script\b(?:(?![^>]+src\b)|(?=[^>]+src\b=["'][^"']+?app\.js))(?!>[^<]+(?:importScript\(\)|toggleOpenSection))(?![^>]+type\s*=\s*["'](?:math\/|[^"']*?math))/i;
     
     // Cache for CSS styles contained in ZIM.
     // It significantly speeds up subsequent page display. See kiwix-js issue #335
@@ -836,6 +869,11 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
      * @param {String} htmlArticle
      */
     function displayArticleContentInIframe(dirEntry, htmlArticle) {
+        // Display Bootstrap warning alert if the landing page contains active content
+        if (!params.hideActiveContentWarning && params.isLandingPage) {
+            if (regexpActiveContent.test(htmlArticle)) uiUtil.displayActiveContentWarning();
+        }
+
         // Replaces ZIM-style URLs of img, script, link and media tags with a data-kiwixurl to prevent 404 errors [kiwix-js #272 #376]
         // This replacement also processes the URL to remove the path so that the URL is ready for subsequent jQuery functions
         htmlArticle = htmlArticle.replace(regexpTagsWithZimUrl, '$1data-kiwixurl$2');
@@ -1132,6 +1170,8 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
                 $("#searchingArticles").hide();
                 alert("Article with title " + title + " not found in the archive");
             } else {
+                params.isLandingPage = false;
+                $('#activeContent').alert('close');
                 readArticle(dirEntry);
             }
         }).fail(function(e) { alert("Error reading article with title " + title + " : " + e); });
@@ -1145,6 +1185,8 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
                 alert("Error finding random article.");
             } else {
                 if (dirEntry.namespace === 'A') {
+                    params.isLandingPage = false;
+                    $('#activeContent').alert('close');
                     readArticle(dirEntry);
                 } else {
                     // If the random title search did not end up on an article,
@@ -1164,6 +1206,7 @@ define(['jquery', 'zimArchiveLoader', 'util', 'uiUtil', 'cookies','abstractFiles
                 $("#welcomeText").show();
             } else {
                 if (dirEntry.namespace === 'A') {
+                    params.isLandingPage = true;
                     readArticle(dirEntry);
                 } else {
                     console.error("The main page of this archive does not seem to be an article");
diff --git a/www/js/lib/uiUtil.js b/www/js/lib/uiUtil.js
index 6c261c6fa..ed043fc0d 100644
--- a/www/js/lib/uiUtil.js
+++ b/www/js/lib/uiUtil.js
@@ -84,12 +84,48 @@ define([], function() {
         return url.replace(regexpRemoveUrlParameters, "$1");
     }
 
+    /**
+     * Displays a Bootstrap warning alert with information about how to access content in a ZIM with unsupported active UI
+     */
+    function displayActiveContentWarning() {
+        // We have to add the alert box in code, because Bootstrap removes it completely from the DOM when the user dismisses it
+        var alertHTML =
+            '<div id="activeContent" class="alert alert-warning alert-dismissible fade in">' +
+                '<a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>' +
+                '<strong>Unable to display active content:</strong> This ZIM is not fully supported in jQuery mode.<br />' +
+                'Content may be available by searching above (type a space or a letter of the alphabet), or else ' +
+                '<a id="swModeLink" href="#contentInjectionModeDiv" class="alert-link">switch to Service Worker mode</a> ' +
+                'if your platform supports it. &nbsp;[<a id="stop" href="#displaySettingsDiv" class="alert-link">Permanently hide</a>]' +
+            '</div>';
+        document.getElementById('alertBoxHeader').innerHTML = alertHTML;
+        ['swModeLink', 'stop'].forEach(function(id) {
+            // Define event listeners for both hyperlinks in alert box: these take the user to the Config tab and highlight
+            // the options that the user needs to select
+            document.getElementById(id).addEventListener('click', function () {
+                var elementID = id === 'stop' ? 'hideActiveContentWarningCheck' : 'serviceworkerModeRadio';
+                var thisLabel = document.getElementById(elementID).parentNode;
+                thisLabel.style.borderColor = 'red';
+                thisLabel.style.borderStyle = 'solid';
+                var btnHome = document.getElementById('btnHome');
+                [thisLabel, btnHome].forEach(function (ele) {
+                    // Define event listeners to cancel the highlighting both on the highlighted element and on the Home tab
+                    ele.addEventListener('mousedown', function () {
+                        thisLabel.style.borderColor = '';
+                        thisLabel.style.borderStyle = '';
+                    });
+                });
+                document.getElementById('btnConfigure').click();
+            });
+        });
+    }
+
     /**
      * Functions and classes exposed by this module
      */
     return {
         feedNodeWithBlob: feedNodeWithBlob,
         replaceCSSLinkWithInlineCSS: replaceCSSLinkWithInlineCSS,
-        removeUrlParameters: removeUrlParameters
+        removeUrlParameters: removeUrlParameters,
+        displayActiveContentWarning: displayActiveContentWarning
     };
 });