Merge pull request #14 from 0xProject/implementFirstExchangeMethod

Implement first exchange method

1 files changed, 48 insertions, 0 deletions

diff --git a/src/ts/contract_wrappers/contract_wrapper.ts b/src/ts/contract_wrappers/contract_wrapper.ts
new file mode 100644
index 000000000..9f4cd8039
--- /dev/null
+++ b/src/ts/contract_wrappers/contract_wrapper.ts
@@ -0,0 +1,48 @@
+import * as _ from 'lodash';
+import contract = require('truffle-contract');
+import {Web3Wrapper} from '../web3_wrapper';
+import {ZeroExError} from '../types';
+import {utils} from '../utils/utils';
+
+export class ContractWrapper {
+    public web3Wrapper: Web3Wrapper;
+    constructor(web3Wrapper: Web3Wrapper) {
+        this.web3Wrapper = web3Wrapper;
+    }
+    protected async instantiateContractIfExistsAsync(artifact: Artifact, address?: string): Promise<ContractInstance> {
+        const c = await contract(artifact);
+        const providerObj = this.web3Wrapper.getCurrentProvider();
+        c.setProvider(providerObj);
+
+        const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync();
+        const artifactNetworkConfigs = _.isUndefined(networkIdIfExists) ?
+                                       undefined :
+                                       artifact.networks[networkIdIfExists];
+        let contractAddress;
+        if (!_.isUndefined(address)) {
+            contractAddress = address;
+        } else if (!_.isUndefined(artifactNetworkConfigs)) {
+            contractAddress = artifactNetworkConfigs.address;
+        }
+
+        if (!_.isUndefined(contractAddress)) {
+            const doesContractExist = await this.web3Wrapper.doesContractExistAtAddressAsync(contractAddress);
+            if (!doesContractExist) {
+                throw new Error(ZeroExError.CONTRACT_DOES_NOT_EXIST);
+            }
+        }
+
+        try {
+            const contractInstance = _.isUndefined(address) ? await c.deployed() : await c.at(address);
+            return contractInstance;
+        } catch (err) {
+            const errMsg = `${err}`;
+            if (_.includes(errMsg, 'not been deployed to detected network')) {
+                throw new Error(ZeroExError.CONTRACT_DOES_NOT_EXIST);
+            } else {
+                utils.consoleLog(`Notice: Error encountered: ${err} ${err.stack}`);
+                throw new Error(ZeroExError.UNHANDLED_ERROR);
+            }
+        }
+    }
+}