Add explicit aria-label to placeholder-only inputs

While `placeholder` is nominally valid per spec
http://rawgit.com/w3c/html-api-map/master/index.html#accessible-name-and-description-calculation
it is inelegant, a fallback, and not supported in ios/safari/voiceover
and android/chrome/talkback, to name a few combinations

`aria-describedby` is also not really the right tool for providing a
name/label equivalent, so remove that from the list of possible
alternative methods / clarify how it can be used

docs/components/button-group.md

@@ -59,7 +59,7 @@ Feel free to mix input groups with button groups in your toolbars. Similar to th
   </div>
   <div class="input-group">
     <span class="input-group-addon" id="btnGroupAddon">@</span>
-    <input type="text" class="form-control" placeholder="Input group example" aria-describedby="btnGroupAddon">
+    <input type="text" class="form-control" placeholder="Input group example" aria-label="Input group example" aria-describedby="btnGroupAddon">
   </div>
 </div>
 
@@ -72,7 +72,7 @@ Feel free to mix input groups with button groups in your toolbars. Similar to th
   </div>
   <div class="input-group">
     <span class="input-group-addon" id="btnGroupAddon2">@</span>
-    <input type="text" class="form-control" placeholder="Input group example" aria-describedby="btnGroupAddon2">
+    <input type="text" class="form-control" placeholder="Input group example" aria-label="Input group example" aria-describedby="btnGroupAddon2">
   </div>
 </div>
 {% endexample %}

docs/components/input-group.md

@@ -19,11 +19,11 @@ Place one add-on or button on either side of an input. You may also place one on
 {% example html %}
 <div class="input-group">
   <span class="input-group-addon" id="basic-addon1">@</span>
-  <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">
+  <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="basic-addon1">
 </div>
 <br>
 <div class="input-group">
-  <input type="text" class="form-control" placeholder="Recipient's username" aria-describedby="basic-addon2">
+  <input type="text" class="form-control" placeholder="Recipient's username" aria-label="Recipient's username" aria-describedby="basic-addon2">
   <span class="input-group-addon" id="basic-addon2">@example.com</span>
 </div>
 <br>
@@ -53,12 +53,12 @@ Add the relative form sizing classes to the `.input-group` itself and contents w
 {% example html %}
 <div class="input-group input-group-lg">
   <span class="input-group-addon" id="sizing-addon1">@</span>
-  <input type="text" class="form-control" placeholder="Username" aria-describedby="sizing-addon1">
+  <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="sizing-addon1">
 </div>
 <br>
 <div class="input-group">
   <span class="input-group-addon" id="sizing-addon2">@</span>
-  <input type="text" class="form-control" placeholder="Username" aria-describedby="sizing-addon2">
+  <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="sizing-addon2">
 </div>
 {% endexample %}
 
@@ -124,12 +124,12 @@ Buttons in input groups must wrapped in a `.input-group-btn` for proper alignmen
       <span class="input-group-btn">
         <button class="btn btn-secondary" type="button">Go!</button>
       </span>
-      <input type="text" class="form-control" placeholder="Search for...">
+      <input type="text" class="form-control" placeholder="Search for..." aria-label="Search for...">
     </div>
   </div>
   <div class="col-lg-6">
     <div class="input-group">
-      <input type="text" class="form-control" placeholder="Search for...">
+      <input type="text" class="form-control" placeholder="Search for..." aria-label="Search for...>
       <span class="input-group-btn">
         <button class="btn btn-secondary" type="button">Go!</button>
       </span>
@@ -143,7 +143,7 @@ Buttons in input groups must wrapped in a `.input-group-btn` for proper alignmen
       <span class="input-group-btn">
         <button class="btn btn-secondary" type="button">Hate it</button>
       </span>
-      <input type="text" class="form-control" placeholder="Product name">
+      <input type="text" class="form-control" placeholder="Product name" aria-label="Product name">
       <span class="input-group-btn">
         <button class="btn btn-secondary" type="button">Love it</button>
       </span>
@@ -240,4 +240,4 @@ Buttons in input groups must wrapped in a `.input-group-btn` for proper alignmen
 
 Screen readers will have trouble with your forms if you don't include a label for every input. For these input groups, ensure that any additional label or functionality is conveyed to assistive technologies.
 
-The exact technique to be used (`<label>` elements hidden using the `.sr-only` class, or use of the `aria-label`, `aria-labelledby`, `aria-describedby`, `title` or `placeholder` attribute) and what additional information will need to be conveyed will vary depending on the exact type of interface widget you're implementing. The examples in this section provide a few suggested, case-specific approaches.
+The exact technique to be used (`<label>` elements hidden using the `.sr-only` class, or use of the `aria-label` and `aria-labelledby` attributes, possibly in combination with `aria-describedby`) and what additional information will need to be conveyed will vary depending on the exact type of interface widget you're implementing. The examples in this section provide a few suggested, case-specific approaches.

docs/components/navbar.md

@@ -57,7 +57,7 @@ Here's an example of all the sub-components included in a responsive light-theme
       </li>
     </ul>
     <form class="form-inline my-2 my-lg-0">
-      <input class="form-control mr-sm-2" type="text" placeholder="Search">
+      <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
       <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
     </form>
   </div>
@@ -192,7 +192,7 @@ Place various form controls and components within a navbar with `.form-inline`.
 {% example html %}
 <nav class="navbar navbar-light bg-faded">
   <form class="form-inline">
-    <input class="form-control mr-sm-2" type="text" placeholder="Search">
+    <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
     <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
   </form>
 </nav>
@@ -204,7 +204,7 @@ Align the contents of your inline forms with utilities as needed.
 <nav class="navbar navbar-light bg-faded justify-content-between">
   <a class="navbar-brand">Navbar</a>
   <form class="form-inline">
-    <input class="form-control mr-sm-2" type="text" placeholder="Search">
+    <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
     <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
   </form>
 </nav>
@@ -217,7 +217,7 @@ Input groups work, too:
   <form class="form-inline">
     <div class="input-group">
       <span class="input-group-addon" id="basic-addon1">@</span>
-      <input type="text" class="form-control" placeholder="Username" aria-describedby="basic-addon1">
+      <input type="text" class="form-control" placeholder="Username" aria-label="Username" aria-describedby="basic-addon1">
     </div>
   </form>
 </nav>
@@ -300,7 +300,7 @@ Theming the navbar has never been easier thanks to the combination of theming cl
         </li>
       </ul>
       <form class="form-inline">
-        <input class="form-control mr-sm-2" type="text" placeholder="Search">
+        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
         <button class="btn btn-outline-info my-2 my-sm-0" type="submit">Search</button>
       </form>
     </div>
@@ -328,7 +328,7 @@ Theming the navbar has never been easier thanks to the combination of theming cl
         </li>
       </ul>
       <form class="form-inline">
-        <input class="form-control mr-sm-2" type="text" placeholder="Search">
+        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
         <button class="btn btn-outline-secondary my-2 my-sm-0" type="submit">Search</button>
       </form>
     </div>
@@ -356,7 +356,7 @@ Theming the navbar has never been easier thanks to the combination of theming cl
         </li>
       </ul>
       <form class="form-inline">
-        <input class="form-control mr-sm-2" type="text" placeholder="Search">
+        <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
         <button class="btn btn-outline-primary my-2 my-sm-0" type="submit">Search</button>
       </form>
     </div>
@@ -458,7 +458,7 @@ With no `.navbar-brand` shown in lowest breakpoint:
       </li>
     </ul>
     <form class="form-inline my-2 my-lg-0">
-      <input class="form-control mr-sm-2" type="text" placeholder="Search">
+      <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
       <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
     </form>
   </div>
@@ -516,7 +516,7 @@ With a toggler on the left and brand name on the right:
       </li>
     </ul>
     <form class="form-inline my-2 my-lg-0">
-      <input class="form-control mr-sm-2" type="text" placeholder="Search">
+      <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
       <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
     </form>
   </div>

docs/examples/carousel/index.html

@@ -35,7 +35,7 @@
           </li>
         </ul>
         <form class="form-inline mt-2 mt-md-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/dashboard/index.html

@@ -39,7 +39,7 @@
           </li>
         </ul>
         <form class="form-inline mt-2 mt-md-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/jumbotron/index.html

@@ -45,7 +45,7 @@
           </li>
         </ul>
         <form class="form-inline my-2 my-lg-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/navbar-top-fixed/index.html

@@ -36,7 +36,7 @@
           </li>
         </ul>
         <form class="form-inline mt-2 mt-md-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/navbar-top/index.html

@@ -36,7 +36,7 @@
           </li>
         </ul>
         <form class="form-inline mt-2 mt-md-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/navbars/index.html

@@ -45,7 +45,7 @@
           </li>
         </ul>
         <form class="form-inline my-2 my-md-0">
-          <input class="form-control" type="text" placeholder="Search">
+          <input class="form-control" type="text" placeholder="Search" aria-label="Search">
         </form>
       </div>
     </nav>
@@ -238,7 +238,7 @@
             </li>
           </ul>
           <form class="form-inline my-2 my-md-0">
-            <input class="form-control" type="text" placeholder="Search">
+            <input class="form-control" type="text" placeholder="Search" aria-label="Search">
           </form>
         </div>
       </div>
@@ -300,7 +300,7 @@
             </li>
           </ul>
           <form class="form-inline my-2 my-md-0">
-            <input class="form-control" type="text" placeholder="Search">
+            <input class="form-control" type="text" placeholder="Search" aria-label="Search">
           </form>
         </div>
       </nav>

docs/examples/offcanvas/index.html

@@ -45,7 +45,7 @@
           </li>
         </ul>
         <form class="form-inline my-2 my-lg-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/starter-template/index.html

@@ -45,7 +45,7 @@
           </li>
         </ul>
         <form class="form-inline my-2 my-lg-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>

docs/examples/sticky-footer-navbar/index.html

@@ -37,7 +37,7 @@
           </li>
         </ul>
         <form class="form-inline mt-2 mt-md-0">
-          <input class="form-control mr-sm-2" type="text" placeholder="Search">
+          <input class="form-control mr-sm-2" type="text" placeholder="Search" aria-label="Search">
           <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
         </form>
       </div>