String comparison not working for text received from web scraping

问题

I am comparing text received from web scraping with hardcoded text in my code. The two texts are identical. No Capital-Small error. They are identical but still the comparison fails. I am sharing a part of my code. The problem is between the lines 47 to 56. Between these lines, the string comparison in if else blocks fails. The values provided for these blocks are perfectly fine values which should ideally satisfy the condition. The if condition at 49 gets satisfied for some reason and the other if conditions don't get satisfied. This behaviour is so weird. The same code when converted in Java runs and works fine without a glitch executing all the if conditions. Please have a look and help. Thanks.

I have tried this with switch case as well but failed with it too.

 import 'package:http/http.dart';
 import 'package:html/parser.dart';
 import 'package:html/dom.dart';
 import 'dart:convert';
 class Worker{

 static final String OperatingCashFlowINRMil = 'Operating Cash Flow INR Mil';
 static final String CapSpendingINRMil = 'Cap Spending INR Mil';
 static final String FreeCashFlowINRMil = 'Free Cash Flow INR Mil';
 static final String DividendsINR = 'Dividends INR';
 static final String DividendPayoutRatio = 'Payout Ratio % *';
 static Map<String,String> _RequestHeaders = Map<String,String>();

 static void fetchData() async
 {
 String MSUrlToGetFinancialData =
    "https://financials.morningstar.com/finan/financials/getFinancePart.html?&callback=jsonp1553353302056&t=0P0000AX98&region=ind&culture=en-US&version=SAL&cur=&order=desc&_=1553353302079";
Client client = Client();

Response response2 = await client.get(MSUrlToGetFinancialData,
    headers: getRequestHeaders());

var FinDataResponse = response2.body;

FinDataResponse = FinDataResponse.replaceAll("jsonp1553353302056(", "");
FinDataResponse =
    FinDataResponse.substring(0, FinDataResponse.length - 1);

JsonDecoder jsonDecoder = JsonDecoder();
var FinDataJson = jsonDecoder.convert(FinDataResponse);
String FinDataString = FinDataJson["componentData"];
Element FinDataDoc = parse(FinDataString).body;
Element DataTable = FinDataDoc.querySelector("table");
List<Element> lstYears = DataTable.querySelector("thead")
    .querySelector("tr")
    .querySelectorAll("th");
List<Element> lstRows =
DataTable.querySelector("tbody").querySelectorAll("tr");

Map<String, Element> mapItemNameToElement = Map<String, Element>();

///////////////////////////////////////////////////////////////////////////0
for (Element e in lstRows) {
  String ItemHeading = e.children[0].text.trim().toString();
  print(ItemHeading);//The identical values which can satisfy the following conditions can be seen printed here.

  if (ItemHeading == DividendsINR) {//This condition does not get satisfied even when the ItemHeading value is identical.
    mapItemNameToElement.putIfAbsent(DividendsINR, () => e);
  } else if (ItemHeading == DividendPayoutRatio) {//This condition gets satisfied.
    mapItemNameToElement.putIfAbsent(DividendPayoutRatio, () => e);
  } else if (ItemHeading == OperatingCashFlowINRMil) {//This condition does not get satisfied even when the ItemHeading value is identical.
    mapItemNameToElement.putIfAbsent(OperatingCashFlowINRMil, () => e);
  } else if (ItemHeading == CapSpendingINRMil) {//This condition does not get satisfied even when the ItemHeading value is identical.
    mapItemNameToElement.putIfAbsent(CapSpendingINRMil, () => e);
  } else if (ItemHeading == FreeCashFlowINRMil) {//This condition does not get satisfied even when the ItemHeading value is identical.
    mapItemNameToElement.putIfAbsent(FreeCashFlowINRMil, () => e);
  }
}
}


static Map<String,String> getRequestHeaders()
{
if(_RequestHeaders.length == 0)
{
  _RequestHeaders.putIfAbsent("Accept-Encoding", () => "gzip, deflate, br");
  _RequestHeaders.putIfAbsent("referer", () => "https://www.morningstar.com/");
  _RequestHeaders.putIfAbsent("user-agent", () => "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36");
  _RequestHeaders.putIfAbsent("authority", () => "www.morningstar.com");
}
return _RequestHeaders;
}
}

My pubspec.yaml :

name: dev1_stock_meter
description: A new Flutter application.

version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  firebase_core: ^0.2.5+1
  firebase_auth: ^0.7.0
  cloud_firestore:
  fluttertoast: ^3.0.4
  autocomplete_textfield: ^1.6.4
  html: ^0.13.3+3
  http: ^0.12.0
  date_format: ^1.0.6
  intl:
  csv: ^4.0.3
  xml:
  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
  sdk: flutter

flutter:
  uses-material-design: true

assets:
  - images/logo.jpg

fonts:
  - family: GoogleSans
    fonts:
      - asset: fonts/GoogleSans-Regular.ttf
        weight: 300
      - asset: fonts/GoogleSans-Bold.ttf
        weight: 400

Expected Result: The if conditions should get satisfied and the Element e should be put in the mapItemNameToElement.

回答1:

Your html string has html entities

Dividends INR does not equal Dividends <span>INR

use https://pub.dartlang.org/packages/html_unescape to decode itemheader before you do comparison

来源：https://stackoverflow.com/questions/55937845/string-comparison-not-working-for-text-received-from-web-scraping

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