clean up logic, more comments, etc.

1 files changed, 98 insertions, 0 deletions

diff --git a/src/frontend/generate_taler_contract.php b/src/frontend/generate_taler_contract.php
new file mode 100644
index 00000000..8dc77da8
--- /dev/null
+++ b/src/frontend/generate_taler_contract.php
@@ -0,0 +1,98 @@
+<?php 
+/*
+  This file is part of TALER
+  Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU General Public License as published by the Free Software
+  Foundation; either version 3, or (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along with
+  TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
+*/
+
+/*  
+  This code generates a Taler contract in JSON format. Key steps are:
+
+  1. recover the PHP session with the contract information
+  2. generate the JSON to forward to the backend
+  3. forward the response with the contract from the backend to
+     to the wallet
+*/
+
+
+// 1) recover the session information
+session_start();
+if ( (! isset($_SESSION['receiver'])) ||
+     (! isset($_SESSION['amount']))
+{
+  http_response_code (404);
+  echo "Please select a contract before getting to this page...";
+  exit (0);
+}
+
+/* Obtain session state */
+$receiver = $_SESSION['receiver'];
+$amount = intval ($_SESSION['amount']);
+
+/* Fill in variables for simple JSON contract */
+// fake product id 
+// --- FIXME: base on receiver for more realism!
+$p_id = rand(0,1001);
+// generate a front-end transaction id. 
+// In production context, we might want to
+// record this value somewhere together
+// with the rest of the contract data.
+$transaction_id = rand(0, 1001);
+// Human-readable description of this deal
+$desc = "Donation to " . $receiver;
+// Add the value
+$value = $amount;
+// We don't have a fraction.
+$fraction = 0;
+// This is our 'toy' currency
+$currency = "KUDOS";
+
+// pack the JSON for the contract 
+// --- FIXME: exact format needs review!
+$json = json_encode (array ('desc' => $desc, 
+                            'product' => $p_id, 
+                            'cid' => $transaction_id,
+                            'price' => array ('value' => $value,
+			                      'fraction' => $fraction,
+                                              'currency' => $currency)));
+
+// Craft the HTTP request, note that the backend
+// could be on an entirely different machine if
+// desired.
+$req = new http\Client\Request ("POST",
+                                "/backend/contract",
+				array ("Content-Type" => "application/json"));
+$req->getBody()->append ($json);
+
+// Execute the HTTP request
+$client = new http\Client;
+$client->enqueue($req)->send ();
+
+// Fetch the response
+$resp = $client->getResponse ();
+$status_code = $resp->getResponseCode ();
+
+// Our response code is the same we got from the backend:
+http_response_code ($status_code);
+
+// Now generate our body  
+if ($status_code != 200)
+{
+  echo "Error while generating the contract, response code: " . $status_code;
+}
+else
+{
+  // send the contract back to the wallet without touching it
+  echo $resp->body->toString ();
+}
+?>