1 files changed, 121 insertions, 4 deletions
diff --git a/src/frontend_blog/teaser.php b/src/frontend_blog/teaser.php
index e5f2e97b..6f404f2b 100644
--- a/src/frontend_blog/teaser.php
+++ b/src/frontend_blog/teaser.php
@@ -33,14 +33,131 @@ $teaser = $doc->getElementById("teaser");
     <?php echo $article ?>
   </title>
 </head>
-<body>
+<body onload="signal_taler_wallet_onload();">
 <?php if ($article == "No article")
         echo "Please select some article";
       else {
         session_start();
 	$_SESSION['article'] = $article;
-	echo $teaser->nodeValue
-	. "<br><a href=\"/essay_checkout.php\">read more</a>";}; ?>
+	echo $teaser->nodeValue;
+      }
+?>
+	<br><a href="cc_payment.html" id="read-more">read more</a>
+
+</body>
+<script>
+/* This function is called from "taler_pay" after
+   we downloaded the JSON contract from the merchant.
+   We now need to pass it to the extension. */
+function handle_contract(json_contract)
+{
+  var cEvent = new CustomEvent('taler-contract', { detail: json_contract });
+
+  document.dispatchEvent(cEvent);
+};
+
+function taler_pay()
+{
+  var contract_request = new XMLHttpRequest();
+
+  /* Note that the URL we give here is specific to the Demo-shop
+     and not required by the protocol: each web shop can
+     have its own way of generating and transmitting the
+     contract, there just must be a way to get the contract
+     and to pass it to the wallet when the user selects 'Pay'. */
+  contract_request.open("GET", "essay_contract.php", true);
+  contract_request.onload = function (e)
+  {
+    if (contract_request.readyState == 4)
+    {
+      if (contract_request.status == 200)
+      {
+        /* display contract_requestificate (i.e. it sends the JSON string
+          to the extension) alert (contract_request.responseText); */
+	console.log("contract here");
+        console.log("response text:", contract_request.responseText);
+        handle_contract(contract_request.responseText);
+      }
+      else
+      {
+        /* There was an error obtaining the contract from the merchant,
+           obviously this should not happen. To keep it simple, we just
+           alert the user to the error. */
+        alert("Failure to download contract from merchant " +
+              "(" + contract_request.status + "):\n" +
+              contract_request.responseText);
+      }
+    }
+  };
+  contract_request.onerror = function (e)
+  {
+    /* There was an error obtaining the contract from the merchant,
+       obviously this should not happen. To keep it simple, we just
+       alert the user to the error. */
+    alert("Failure requesting the contract:\n" + contract_request.statusText);
+  };
+  contract_request.send(null);
+}
+
+/* The following event gets fired whenever a customer has a Taler
+   wallet installed in his browser. In that case, the webmaster can decide
+   whether or not to display/enable Taler as a payment option in the dialog. */
+function has_taler_wallet_cb(aEvent)
+{
+  console.log("has taler wallet");
+  // make "read more" trigger Taler payment
+  var rm = document.getElementById("read-more");
+  rm.setAttribute("href", "javascript:taler_pay();");
+};
+
+/* Function called when the Taler extension was unloaded;
+   here we disable the Taler option and check "Lisa", as
+   some "valid" option should always be selected. */
+function taler_wallet_unload_cb(aEvent)
+{
+  var rm = document.getElementById("read-more");
+  rm.setAttribute("href", "cc_payment.html");
+};
+
+
+/* The merchant signals its taler-friendlyness to the wallet,
+   thereby causing the wallet to make itself more visible in the menu.
+   This function should be called both when the page is loaded
+   (i.e. via body's onload) and when we receive a "taler-load" signal
+   (as the extension may be loaded/enabled after the page was loaded) */
+function signal_taler_wallet_onload()
+{
+  var eve = new Event('taler-probe');
+  document.dispatchEvent(eve);
+};
+
+
+// function included to be run to test the page despite a
+// wallet not being present in the browser.  Enables the
+// Taler option. NOT needed in real deployments.
+function test_without_wallet(){
+  var tbutton = document.getElementById("taler-radio-button-id");
+  tbutton.removeAttribute("disabled");
+};
+
+
+// /////////////// Main logic run first ////////////////////////
+
+// Register event to be triggered by the wallet as a response to our
+// first event
+document.addEventListener("taler-wallet-present",
+                          has_taler_wallet_cb,
+			  false);
+
+// Register event to be triggered by the wallet when it gets enabled while
+// the user is on the payment page
+document.addEventListener("taler-load",
+                          signal_taler_wallet_onload,
+			  false);
 
-<body>
+// Register event to be triggered by the wallet when it is unloaded
+document.addEventListener("taler-unload",
+                          taler_wallet_unload_cb,
+	                  false);
+</script>
 </html>