e-book

flea-market-contract-service.ts

import { Injectable } from '@angular/core';
import { MarketPlaceAnchorModule } from '../market-place-anchor.module';
import { FleaMarketContractToken } from './tokens/flea-market-contract-token';
import { Observable, from, of, forkJoin } from 'rxjs';
import { map, tap, switchMap, mergeMap, exhaustMap } from 'rxjs/operators';
import { ethers, utils } from 'ethers';
import { PurchaseWidgetModel } from '../models';

@Injectable({ providedIn: MarketPlaceAnchorModule })
export class FleaMarketContractService {
  constructor(private contractToken: FleaMarketContractToken) {
  }

  public createPurchaseContract(product: any): Observable<string> {

    const commission = Math.floor(parseFloat(product.commission) * 100);
    const bytes32Key = utils.formatBytes32String(product.productKey);
    const wei = utils.parseEther(product.etherValue);

    // based on https://docs.ethers.io/ethers.js/html/cookbook-contracts.html
    // Call the contract method, getting back the transaction tx
    const token =
      this.contractToken.createPurchaseContract(bytes32Key, product.description, 
                                                product.ipfsHash, commission, {
        value: wei
      });
    return from(token)
      .pipe(
        switchMap((tx: any) => {
    
          console.log('Transaction', tx);
          // Wait for transaction to be mined
          // Returned a Promise which would resolve to the TransactionReceipt 
          // once it is mined.
          return from(tx.wait()).pipe(
            tap((txReceipt: any) => console.log('TransactionReceipt: ', txReceipt)),

            // The receipt will have an "events" Array, which will have
            // the emitted 
            // 'event LogCreatePurchaseContract(address sender, address contractAddress)'.
            map(txReceipt => txReceipt.events.pop()),
            map(txEvent => txEvent.args.contractAddress),
            tap(address => console.log('address: ', address)));
        }));
  }