CasperJS/PhantomJS .then in do/while Loop Doesn't Work

问题

Something like this seemed pretty logical to me but caused phantom to wtfcrash (That's what it's called in the log but doesn't give helpful info)...

do {
    casper.then(function() {
        var targetFound = false;
        links = this.evaluate(getLinks);

        var searchResultsAr = [];
        for (var link in links) {
            searchResultsAr.push(links[link].replace('/url?q=', '').split('&sa=U')[0]);
        }

        for (var result in searchResultsAr) {
            if (searchResultsAr[result] == target) {
                targetFound = true;
                casper.echo(targetFound);
                break;
            }
        }
        if(targetFound)
        {
            break;
        }
    });
}while(!targetFound);

回答1:

There are different possibilies, if you just want to repeat things static times you can use casper.repeat() -> how to have a variable value for casper.repeat

If you want to do a while with multipe then's inside and a break point you still have to use a recursive function as far as i know. Here is an example:

  ...
  casper.then(function() {
    loopValidConf.call(this, 0, 15);
  });
  casper.then(function() {
    casper.test.assert(exists, 'true after 15 tries!')
  });

  function loopValidConf(index, numTimes) {
    if (exists === true || index >= numTimes) {
      return;
    }
    casper.then(function() {
      casper.reload(function() {
        casper.echo("reset values");
      });
      casper.then(function() {
        // set some values here
      });
      casper.then(function() {
        casper.waitForSelector(".selector")
      });
      casper.then(function() {
        if (casper.exists('.targetSelector')) {
          exists = true;
          casper.echo('targetSelector exists!');
        } else {
          casper.echo('targetSelector doesnt exists, try it once more!');
        }
      });
    });
    casper.then(function() {
      loopValidConf.call(this, index + 1, numTimes);
    });
  }
  ...

This is still not the optimum (could cause memory problems), but it works. :)

来源：https://stackoverflow.com/questions/41964704/casperjs-phantomjs-then-in-do-while-loop-doesnt-work

标签

javascript

loops

phantomjs

casperjs