Merge pull request #95 from 0xProject/cache_net_version

Cache `net_version` requests

1 files changed, 8 insertions, 1 deletions

diff --git a/src/web3_wrapper.ts b/src/web3_wrapper.ts
index 630f0bef3..61bac45c9 100644
--- a/src/web3_wrapper.ts
+++ b/src/web3_wrapper.ts
@@ -5,11 +5,13 @@ import promisify = require('es6-promisify');
 
 export class Web3Wrapper {
     private web3: Web3;
+    private networkIdIfExists?: number;
     constructor(provider: Web3.Provider) {
         this.web3 = new Web3();
         this.web3.setProvider(provider);
     }
     public setProvider(provider: Web3.Provider) {
+        delete this.networkIdIfExists;
         this.web3.setProvider(provider);
     }
     public isAddress(address: string): boolean {
@@ -27,9 +29,14 @@ export class Web3Wrapper {
         return this.web3.currentProvider;
     }
     public async getNetworkIdIfExistsAsync(): Promise<number|undefined> {
+        if (!_.isUndefined(this.networkIdIfExists)) {
+          return this.networkIdIfExists;
+        }
+
         try {
             const networkId = await this.getNetworkAsync();
-            return Number(networkId);
+            this.networkIdIfExists = Number(networkId);
+            return this.networkIdIfExists;
         } catch (err) {
             return undefined;
         }