Support querying smart contracts for template data

api/controller.js

@@ -78,7 +78,6 @@ class Controller {
 
   static unsubscribe(dappConfig) {
     return async (req, res) => {
-      // TODO:
       const {
         params: { dappId },
         body: { address, signature }

dapps/teller-network/config.js

@@ -1,3 +1,32 @@
+
+const ERC20_ABI = [
+  {
+    constant: true,
+    inputs: [],
+    name: "name",
+    outputs: [
+      {
+        name: "",
+        type: "string"
+      }
+    ],
+    payable: false,
+    stateMutability: "view",
+    type: "function"
+  },
+  {
+    constant: true,
+    type: "function",
+    name: "balanceOf",
+    inputs: [
+      { name: "owner", type: "address" }
+    ],
+    outputs: [{ name: "balance", type: "uint256" }],
+    stateMutability: "view"
+  },
+];
+
+
 module.exports = {
   from: {
     email: "noreply@teller.exchange",
@@ -27,7 +56,15 @@ module.exports = {
             template: {
               subject: "New trade!",
               html: "escrow-creation.html",
-              text: "escrow-creation.txt"
+              text: "escrow-creation.txt",
+              data: async (web3, returnValues) => {
+                // Example obtaining contract data
+                const SNT = new web3.eth.Contract(ERC20_ABI, "0x3C36db79598e7902b5D726af7C7d406d5Da8aF14");
+                return {
+                  'tokenName': await SNT.methods.name().call(),
+                  'balance': await SNT.methods.balanceOf(returnValues.seller).call()
+                };
+              }
             }
           },
           "escrow-funded": {

watcher/index.js

@@ -18,8 +18,7 @@ eth.init();
 
 events.on("db:connected", () => {
   events.on("web3:connected", () => {
-    const blockNum =
-      process.argv.length >= 3 ? parseInt(process.argv[2], 10) : 0;
+    const blockNum = process.argv.length >= 3 ? parseInt(process.argv[2], 10) : 0;
 
     dappConfig.getDapps().forEach(dappId => {
       const contracts = dappConfig.contracts(dappId);
@@ -33,17 +32,24 @@ events.on("db:connected", () => {
 events.on("web3:event", ({ dappId, address, event, returnValues }) => {
   dappConfig.eventConfig(dappId, address, event).forEach(async eventConfig => {
     const users = await Subscribers.findVerifiedUsersByDapp(dappId);
-    users.forEach(user => {
+    users.forEach(async user => {
       if (addressCompare(returnValues[eventConfig.index], user.address)) {
         console.log("Sending email...");
-        mailer.send(
-          dappConfig.getEmailTemplate(dappId, eventConfig.template),
-          dappConfig.config(dappId).from,
-          {
-            email: user.email,
-            ...returnValues
+
+        let data = {
+          email: user.email,
+          ...returnValues
+        };
+
+        if (eventConfig.template.data) {
+          try {
+            data = Object.assign(data, await eventConfig.template.data(eth.web3, returnValues));
+          } catch (err) {
+            console.err("Error using data function", err);
           }
-        );
+        }
+
+        mailer.send(dappConfig.getEmailTemplate(dappId, eventConfig.template), dappConfig.config(dappId).from, data);
       }
     });
   });