CODEWITHSUNDEEP
javascriptprotractor
NewWorld
NewWorld

Reputation: 764

Issue validating in all rows of a table

I have a table which consist of around 50 rows and columns on a page. I want to fetch all rows from table and write a function to check if 2nd column of all words contains word 'Silver'. I tried below code but it is not working. Can someone please help where i am missing an i am not that great with Javascript promises. If match to string is found, i just want to increment a count and then return count at end.

  fetchValues(SearchString){
      var matchcount=0;
      var count = this.ContentTable.Rows.count();
      for (var i=0;i<count-1;i++) {
           return this.ContentTable.element(by.css('[id*="DXDataRow'+i+'"]'))
           .then((Row) =>{
                return this.ContentTable.Row.element(by.css('[id*="uxSetList_tccell'+i+'_1"]'))
                .then((Column)=>{
                        var CoinInfo = this.ContentTable.Row.Column.element(by.css('a')).getText();
                        if (CoinInfo.indexOf(SearchString)>=0)
                        {
                            matchcount =matchcount+1
                        }
                        return matchcount;
                });
           });                
      }
       }

Upvotes: 2

Views: 54

Answers (1)

Dan O
Dan O

Reputation: 6090

first of all, you're returning a value from inside your for() loop. That guarantees your loop is only ever going to be run once, and you're only ever going to examine one row. Is that what you want? (no, really, I have no idea.) Are you trying to create a lot of promises and combine their results into a single number? You might want to use Promise.all() to combine the values of all promises you create, and return a value from that meta-promise:

var myPromises = [];
for (var i = 0; i < count; i++) {
  myPromises.push(this.ContentTable.element(by.css('[id*="DXDataRow'+i+'"]'))
    .then(/* ...blah blah blah ... */)
  );
}
// return a single value from this function containing data from all promises
return Promise.all(myPromises).then((promiseResultsArray) => {
    /* calculate match count */
});

second, I think your promises themselves are written incorrectly. You're assuming that the value of i when your promise's callback is run is the same as the value of i when your promise's callback was defined. Because of how promises work in JS, that's not actually the case.

What's happening is that your for() loop creates a bunch of promises and then, at some undefined point in the future, one of these promises gets resolved and the function you passed to its .then() method gets run. This function knows about i - it's right there in the function body, after all! - but the value of i right now is equal to the value of count - 1. We're in the future now, remember, and the for() loop has terminated, and the termination condition for your loop is when i === count - 1. This will be the case for every single promise you create in this loop, because they all get executed after the loop terminates.

You can fix this in a bunch of ways. Probably the cleanest is to declare a new variable, initialized to the current value of i and never ever changed, and refer to that inside your .then() callback:

var i = 0;
var myPromises = [];
for (i = 0; i < count; i++) {
  var currentCount = i;
  myPromises.push(this.ContentTable.element(by.css('[id*="DXDataRow'+currentCount+'"]'))
    .then(/* ...blah blah blah ... */)
  );
}
// return a single value from this function containing data from all promises
return Promise.all(myPromises).then((promiseResultsArray) => {
    /* calculate match count */
});

if you want more information, there are plenty of SO questions about how to use promises.

Upvotes: 1

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