Initial commit

static/lib.js

@@ -0,0 +1,85 @@
+function checkUsername(u){
+  var starts_with_period = /^\./.test(u);
+  var ends_with_period = /\.$/.test(u);
+  var two_periods = /\.\./.test(u);
+  var forbidden_extensions = u.match(/\.(com|net|org|txt)$/);
+  
+  return (
+    starts_with_period? 'You cannot start username with a period.':
+    ends_with_period? 'You cannot end username with a period.':
+    two_periods? 'You cannot have more than one period in a row.':
+    forbidden_extensions? 'Your username cannot end with .' + forbidden_extensions[1]:
+    'ok'
+  );
+}
+
+function attachUsernameInput(){
+  var usernameInputs = document.getElementsByClassName('username-input');
+  for(var i=0;i<usernameInputs.length;i++)(function(usernameInput){
+    var lastValue = '';
+    var usernameInputMessage = document.createElement('div');
+    usernameInput.oninput = function(event){
+      var value = usernameInput.value;
+      if (value != lastValue){
+        if(!/^[a-z0-9_. ]*$/i.test(value)){
+          usernameInputMessage.innerHTML = 'Usernames can only contain letters, numbers, underscores, and periods.';
+          usernameInputMessage.className = 'username-input-message error';
+          event.preventDefault();
+          return;
+        }
+        if(/ /.test(value)){
+          value = value.replace(/ /g,'_');
+        }
+        usernameInput.value = lastValue = value.toLowerCase();
+        if(!value){
+          usernameInputMessage.innerHTML = 'You cannot have an empty username.';
+          usernameInputMessage.className = 'username-input-message error';
+          return;
+        }
+        var message = checkUsername(value);
+        if (message != 'ok'){
+          usernameInputMessage.innerHTML = message;
+          usernameInputMessage.className = 'username-input-message error';
+          return;
+        }
+        usernameInputMessage.innerHTML = 'Checking username...';
+        usernameInputMessage.className = 'username-input-message checking';
+        requestUsernameAvailability(value, function(resp){
+          if (resp.status != 'ok'){
+            usernameInputMessage.innerHTML = 'Sorry, there was an unknown error.';
+            usernameInputMessage.className = 'username-input-message error';
+            return;
+          }
+          if (resp.is_available){
+            usernameInputMessage.innerHTML = "The username '" + value + "' is available.";
+            usernameInputMessage.className = 'username-input-message success';
+            return;
+          } else {
+            usernameInputMessage.innerHTML = "The username '" + value + "' is not available.";
+            usernameInputMessage.className = 'username-input-message error';
+            return;
+          }
+        });
+      }
+    };
+    usernameInputMessage.className = 'username-input-message';
+    usernameInput.parentNode.appendChild(usernameInputMessage);
+  })(usernameInputs[i]);
+}
+
+attachUsernameInput();
+
+function requestUsernameAvailability(u, callback){
+  var xhr = new XMLHttpRequest();
+  xhr.open('GET', '/ajax/username_availability/' + u, true);
+  xhr.onreadystatechange = function(){
+    if (xhr.readyState == XMLHttpRequest.DONE){
+      try {
+        var data = JSON.parse(xhr.responseText);
+        callback(data);
+      } catch(ex) {
+      }
+    }
+  }
+  xhr.send();
+}