Added option to disable jQuery and heavy javascript

Shaarli uses light Javascript in its normal operation, and some jQuery
for some features (autocomplete in tags, QR-Code popup...).
jQuery can be slow on small computers. An option has been added in
configuration screen to disable javascript features which are hard on
CPU.
(Note that the Picture Wall is awfully heavy *without* jQuery.)

(Side note: A *LOT* of users want Shaarli to work without javasript at
all, if possible. That's why I try to use as few javascript as possible:
It keeps Shaarli pages fast.)

index.php

@@ -96,6 +96,8 @@ require $GLOBALS['config']['CONFIG_FILE'];  // Read login/password hash into $GL
 if (empty($GLOBALS['title'])) $GLOBALS['title']='Shared links on '.htmlspecialchars(indexUrl());
 if (empty($GLOBALS['timezone'])) $GLOBALS['timezone']=date_default_timezone_get();
 if (empty($GLOBALS['disablesessionprotection'])) $GLOBALS['disablesessionprotection']=false;
+if (empty($GLOBALS['disablejquery'])) $GLOBALS['disablejquery']=false;
+// I really need to rewrite Shaarli with a proper configuation manager.
 
 autoLocale(); // Sniff browser language and set date format accordingly.
 header('Content-Type: text/html; charset=utf-8'); // We use UTF-8 for proper international characters handling.
@@ -1350,6 +1352,7 @@ function renderPage()
             $GLOBALS['title']=$_POST['title'];
             $GLOBALS['redirector']=$_POST['redirector'];
             $GLOBALS['disablesessionprotection']=!empty($_POST['disablesessionprotection']);
+            $GLOBALS['disablejquery']=!empty($_POST['disablejquery']);
             writeConfig();
             echo '<script language="JavaScript">alert("Configuration was saved.");document.location=\'?do=tools\';</script>';
             exit;
@@ -1951,6 +1954,11 @@ function lazyThumbnail($url,$href=false)
     $html='<a href="'.htmlspecialchars($t['href']).'">';
     
     // Lazy image (only loaded by javascript when in the viewport).
+    if (!empty($GLOBALS['disablejquery'])) // (except if jQuery is disabled)
+        $html.='<img class="lazyimage" src="'.htmlspecialchars($t['src']).'"';
+    else
+        $html.='<img class="lazyimage" src="#" data-original="'.htmlspecialchars($t['src']).'"';
+
     $html.='<img class="lazyimage" src="#" data-original="'.htmlspecialchars($t['src']).'"';
     if (!empty($t['width']))  $html.=' width="'.htmlspecialchars($t['width']).'"';
     if (!empty($t['height'])) $html.=' height="'.htmlspecialchars($t['height']).'"';
@@ -1958,7 +1966,7 @@ function lazyThumbnail($url,$href=false)
     if (!empty($t['alt']))    $html.=' alt="'.htmlspecialchars($t['alt']).'"';
     $html.='>';
     
-    // No-javascript fallback:
+    // No-javascript fallback.
     $html.='<noscript><img src="'.htmlspecialchars($t['src']).'"';
     if (!empty($t['width']))  $html.=' width="'.htmlspecialchars($t['width']).'"';
     if (!empty($t['height'])) $html.=' height="'.htmlspecialchars($t['height']).'"';
@@ -2065,8 +2073,8 @@ function templateTZform($ptz=false)
         foreach($continents as $continent)
             $continents_html.='<option  value="'.$continent.'"'.($pcontinent==$continent?'selected':'').'>'.$continent.'</option>';
         $cities_html = $cities[$pcontinent];
-        $timezone_form = "Continent: <select name=\"continent\" id=\"continent\" onChange=\"onChangecontinent();\">${continents_html}</select><br /><br />";
-        $timezone_form .= "City: <select name=\"city\" id=\"city\">${cities[$pcontinent]}</select><br /><br />";
+        $timezone_form = "Continent: <select name=\"continent\" id=\"continent\" onChange=\"onChangecontinent();\">${continents_html}</select>";
+        $timezone_form .= "&nbsp;&nbsp;&nbsp;&nbsp;City: <select name=\"city\" id=\"city\">${cities[$pcontinent]}</select><br />";
         $timezone_js = "<script language=\"JavaScript\">";
         $timezone_js .= "function onChangecontinent(){document.getElementById(\"city\").innerHTML = citiescontinent[document.getElementById(\"continent\").value];}";
         $timezone_js .= "var citiescontinent = ".json_encode($cities).";" ;
@@ -2137,12 +2145,11 @@ function processWS()
 function writeConfig()
 {
     if (is_file($GLOBALS['config']['CONFIG_FILE']) && !isLoggedIn()) die('You are not authorized to alter config.'); // Only logged in user can alter config.
-    if (empty($GLOBALS['redirector'])) $GLOBALS['redirector']='';
-    if (empty($GLOBALS['disablesessionprotection'])) $GLOBALS['disablesessionprotection']=false;
     $config='<?php $GLOBALS[\'login\']='.var_export($GLOBALS['login'],true).'; $GLOBALS[\'hash\']='.var_export($GLOBALS['hash'],true).'; $GLOBALS[\'salt\']='.var_export($GLOBALS['salt'],true).'; ';
     $config .='$GLOBALS[\'timezone\']='.var_export($GLOBALS['timezone'],true).'; date_default_timezone_set('.var_export($GLOBALS['timezone'],true).'); $GLOBALS[\'title\']='.var_export($GLOBALS['title'],true).';';
     $config .= '$GLOBALS[\'redirector\']='.var_export($GLOBALS['redirector'],true).'; ';
     $config .= '$GLOBALS[\'disablesessionprotection\']='.var_export($GLOBALS['disablesessionprotection'],true).'; ';
+    $config .= '$GLOBALS[\'disablejquery\']='.var_export($GLOBALS['disablejquery'],true).'; ';
     $config .= ' ?>';
     if (!file_put_contents($GLOBALS['config']['CONFIG_FILE'],$config) || strcmp(file_get_contents($GLOBALS['config']['CONFIG_FILE']),$config)!=0)
     {

tpl/configure.html

@@ -8,10 +8,19 @@
     <form method="POST" action="" name="configform" id="configform">
 	<input type="hidden" name="token" value="{$token}">
 	<table border="0" cellpadding="20">
+
 	    <tr><td><b>Page title:</b></td><td><input type="text" name="title" id="title" size="50" value="{$title}"></td></tr>
-	  <tr><td valign="top"><b>Timezone:</b></td><td>{$timezone_form}</td></tr>
+
+	    <tr><td valign="top"><b>Timezone:</b></td><td valign="top">{$timezone_form}</td></tr>
+
 	    <tr><td valign="top"><b>Redirector</b></td><td><input type="text" name="redirector" id="redirector" size="50" value="{$redirector}"><br>(e.g. <i>http://anonym.to/?</i> will mask the HTTP_REFERER)</td></tr>
-      <tr> <td valign="top">Security:</td> <td><input type="checkbox" name="disablesessionprotection" id="disablesessionprotection" {if="!empty($GLOBALS['disablesessionprotection'])"}checked{/if}><label for="disablesessionprotection">&nbsp;Disable session cookie hijacking protection (Check this if you get disconnected often or if your IP address changes often.)</label></td></tr>
+
+        <tr><td valign="top"><b>Security:</b></td><td><input type="checkbox" name="disablesessionprotection" id="disablesessionprotection" {if="!empty($GLOBALS['disablesessionprotection'])"}checked{/if}><label for="disablesessionprotection">&nbsp;Disable session cookie hijacking protection (Check this if you get disconnected often or if your IP address changes often.)</label></td></tr>
+
+        <tr><td valign="top"><b>Features:</b></td><td>
+        	<input type="checkbox" name="disablejquery" id="disablejquery" {if="!empty($GLOBALS['disablejquery'])"}checked{/if}><label for="disablejquery">&nbsp;Disable jQuery and all heavy javascript (for example: Autocomplete in tags. Useful for slow computers.)</label>
+        </tr>
+
 	  <tr><td></td><td align="right"><input type="submit" name="Save" value="Save config" class="bigbutton"></td></tr>
 	</table>
 	</form>

tpl/includes.html

@@ -7,4 +7,4 @@
 <link href="images/favicon.ico#" rel="shortcut icon" type="image/x-icon" />
 <link type="text/css" rel="stylesheet" href="inc/shaarli.css?version={$version|urlencode}#" />
 {if condition="is_file('inc/user.css')"}<link type="text/css" rel="stylesheet" href="inc/user.css?version={$version}#" />{/if}
-<script src="inc/jquery.min.js#"></script><script src="inc/jquery-ui.min.js#"></script>
+{if="empty($GLOBALS['disablejquery'])"}<script src="inc/jquery.min.js#"></script><script src="inc/jquery-ui.min.js#"></script>{/if}

tpl/linklist.html

@@ -48,7 +48,8 @@
                 {else}
                     <span class="linkdate" title="Short link here"><a href="?{$value.linkdate|smallHash}">permalink</a> - </span>
                 {/if}
-                <div style="position:relative;display:inline;"><a href="http://invx.com/code/qrcode/?code={$scripturl|urlencode}%3F{$value.linkdate|smallHash}&width=200&height=200" onclick="return false;" class="qrcode"><img src="images/qrcode.png#" width="13" height="13" title="QR-Code"></a></div> - 
+                <div style="position:relative;display:inline;"><a href="http://invx.com/code/qrcode/?code={$scripturl|urlencode}%3F{$value.linkdate|smallHash}&width=200&height=200" 
+                    {if="empty($GLOBALS['disablejquery'])"}onclick="return false;"{/if} class="qrcode"><img src="images/qrcode.png#" width="13" height="13" title="QR-Code"></a></div> - 
                 <span class="linkurl" title="Short link">{$value.url|htmlspecialchars}</span><br>
                 {if="$value.tags"}
                     <div class="linktaglist">
@@ -65,6 +66,7 @@
 </div>
 
     {include="page.footer"}
+{if="empty($GLOBALS['disablejquery'])"}    
 <script>
 $(document).ready(function() {
 	$('a.qrcode').click(function(){
@@ -75,5 +77,6 @@ $(document).ready(function() {
 });
 function hide_qrcode() { $('div.qrcode').remove(); }
 </script>
+{/if}
 </body>
 </html>

tpl/page.footer.html

@@ -8,7 +8,7 @@
 <script language="JavaScript">function confirmDeleteLink() { var agree=confirm("Are you sure you want to delete this link ?"); if (agree) return true ; else return false ; }</script>
 {/if}
 
-{if="$GLOBALS['config']['OPEN_SHAARLI'] || isLoggedIn()"}
+{if="($GLOBALS['config']['OPEN_SHAARLI'] || isLoggedIn()) && empty($GLOBALS['disablejquery'])"}
 <script language="JavaScript">
 $(document).ready(function()
 {

tpl/picwall.html

@@ -1,7 +1,9 @@
 <!DOCTYPE html>
 <html>
 <head>{include="includes"}
-<script src="inc/jquery.lazyload.min.js#"></script>
+{if="empty($GLOBALS['disablejquery'])"}	
+	<script src="inc/jquery.lazyload.min.js#"></script>
+{/if}
 </head>
 <body>
 <div id="pageheader">{include="page.header"}</div>
@@ -16,9 +18,11 @@
 </center>
 {include="page.footer"}
 </body>
+{if="empty($GLOBALS['disablejquery'])"} 
 <script>
 $(document).ready(function() {
     $("img.lazyimage").show().lazyload();
 });
 </script>
+{/if} 
 </html>