Add redirect resolver controlled by server (#46)

.gitignore

@@ -1,3 +1,4 @@
 dist/*.adv.js
 /node_modules/
 /public/
+/gostatic

twinspark.js

@@ -465,7 +465,8 @@
           var headers = {'ts-title':     xhr.getResponseHeader('ts-title'),
                          'ts-history':   xhr.getResponseHeader('ts-history'),
                          'ts-swap':      xhr.getResponseHeader('ts-swap'),
-                         'ts-swap-push': xhr.getResponseHeader('ts-swap-push')};
+                         'ts-swap-push': xhr.getResponseHeader('ts-swap-push'),
+                         'ts-location':  xhr.getResponseHeader('ts-location')};
 
         return resolve({ok:      xhr.status >= 200 && xhr.status <= 299,
                         status:  xhr.status,
@@ -1328,6 +1329,13 @@
     return swap(origins, replyParent, res);
   }
 
+  // Handler redirect response, when response headers has params `ts-location`
+  // `targetUrl` - target url getting from server response headers `ts-location`
+  function redirectResponse(targetUrl, res) {
+    location.href = targetUrl;
+    return res;
+  }
+
 
   /// Making request for fragments
 
@@ -1443,6 +1451,11 @@
 
         if (res.ok) {
           res = /** @type !Response */ (res);
+
+          if(res.headers['ts-location']) {
+            return redirectResponse(res.headers['ts-location'], res);
+          }
+
           let redirected = (res.url &&
                             (res.url != new URL(fullurl, location.href).href));
 

www/api.md

@@ -82,6 +82,7 @@ title: API
 <tr><td><code>ts-swap-push</code></td> <td>"Push" some HTML, <code>replace: selector to <= selector from</code></td></tr>
 <tr><td><code>ts-history</code></td>   <td>New browser history URL</td></tr>
 <tr><td><code>ts-title</code></td>     <td>New page title in case of history push</td></tr>
+<tr><td><code>ts-location</code></td>     <td>Redirect to target URL</td></tr>
 
 </table>
 

www/examples/155-redirect-from-server.html

@@ -0,0 +1,28 @@
+id: server-redirect
+title: Redirect from server
+tags: ts-location
+----
+<p>
+  Redirect to target url, pass to response headers <code>ts-location</code> parameter.
+</p>
+
+
+<div class="card example">
+  <div class="card-header">
+    <h5 class="d-inline mr-2">Demo</h5>
+    <button class="btn btn-link btn-sm reset">Reset</button>
+    <button class="btn btn-link btn-sm source">View Source</button>
+  </div>
+
+  <div class="card-body" style="margin-bottom: 1.2rem" id="redirect-example">
+    <button class="btn" ts-req="/redirect" >
+      Click to redirect
+    </button>
+  </div>
+
+  <script>
+    XHRMock.get("/redirect",
+                {body:    prev(),
+                 headers: {'ts-location': 'https://github.com/piranha/twinspark-js'}});
+  </script>
+</div>