Updated contract with withdraw method; removed message event

lukem512 · Dec 2, 2017 · 3e5d625 · 3e5d625
1 parent 0822e84
commit 3e5d625
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Showing 2 changed files with 59 additions and 26 deletions.
diff --git a/contracts/smartdice.sol b/contracts/smartdice.sol
@@ -5,11 +5,12 @@ contract SmartDice is usingOraclize {
 
     string public lastRoll;
     string public lastPrice;
+    address owner;
     event diceRolled(uint value);
-    event message(string description);
 
     function SmartDice() payable {
         rollDice();
+        owner = msg.sender;
     }
 
     function __callback(bytes32 myid, string result) {
@@ -18,20 +19,40 @@ contract SmartDice is usingOraclize {
         diceRolled(parseInt(lastRoll));
     }
 
-    function rollDice() payable {
+    function rollDice() payable returns (bool) {
         // Retrieve price for oraclize query
         uint oraclizePrice = oraclize_getPrice("WolframAlpha");
-
-        // Throw if not covered by the sender
-        if (msg.value < oraclizePrice) throw;
-
-        // Sanity check contract balance is sufficient
-        if (oraclizePrice > this.balance) {
-            message("Could not retrieve random number, please add some ETH to cover the query fee");
-        } else {
-            lastPrice = uint2str(oraclizePrice);
-            message("Rolling the dice...");
-            oraclize_query("WolframAlpha", "random number between 1 and 6");
+
+        // Check the price is covered by the transaction
+        if (msg.value < oraclizePrice) {
+          return false;
+        }
+
+        // Update last lastPrice
+        lastPrice = uint2str(oraclizePrice);
+
+        // Call WolframAlpha via Oraclize to roll the dice
+        oraclize_query("WolframAlpha", "random number between 1 and 6");
+
+        return true;
+    }
+
+    function withdraw(uint amount) returns (bool) {
+        // Only the owner may withdraw
+        if (msg.sender != owner) {
+            return false;
+        }
+
+        // Sanity check balance
+        if (amount > this.balance) {
+            return false;
         }
+
+        // Try to send, throw if
+        if (!msg.sender.send(amount)) {
+            return false;
+        }
+
+        return true;
     }
 }
diff --git a/web/abi.json b/web/abi.json
@@ -31,6 +31,25 @@
     "stateMutability": "nonpayable",
     "type": "function"
   },
+  {
+    "constant": false,
+    "inputs": [
+      {
+        "name": "amount",
+        "type": "uint256"
+      }
+    ],
+    "name": "withdraw",
+    "outputs": [
+      {
+        "name": "",
+        "type": "bool"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "nonpayable",
+    "type": "function"
+  },
   {
     "constant": false,
     "inputs": [
@@ -57,7 +76,12 @@
     "constant": false,
     "inputs": [],
     "name": "rollDice",
-    "outputs": [],
+    "outputs": [
+      {
+        "name": "",
+        "type": "bool"
+      }
+    ],
     "payable": true,
     "stateMutability": "payable",
     "type": "function"
@@ -93,17 +117,5 @@
     ],
     "name": "diceRolled",
     "type": "event"
-  },
-  {
-    "anonymous": false,
-    "inputs": [
-      {
-        "indexed": false,
-        "name": "description",
-        "type": "string"
-      }
-    ],
-    "name": "message",
-    "type": "event"
   }
 ]