setInterval and this.wait in casper.js
casperjs, javascript, phantomjs, qtwebkit, webkit
Solution
Here's a sample implementation to solve your problem:
var casper = require('casper').create();
var last, list = [0, 1, 2, 3];
casper.start("http://google.fr/", function() {
this.echo('google');
});
casper.on('remote.message', function(msg) {
this.echo('remote message caught: ' + msg);
});
casper.thenEvaluate(function() {
window.x = 0;
var intervalID = setInterval(function() {
console.log("Using setInternal " + window.x);
if (++window.x === 3) {
window.clearInterval(intervalID);
}
}, 500);
});
casper.each(list, function(self, i) {
self.wait(500, function() {
last = i;
this.echo('Using this.wait ' + i);
});
});
casper.waitFor(function() {
return last === list[list.length - 1] && 3 === this.getGlobal('x');
}, function() {
this.echo('All done.').exit();
});
casper.run(function() {});
Sample output:
$ casperjs test.js
google
remote message caught: Using setInternal 0
Using this.wait 0
remote message caught: Using setInternal 1
Using this.wait 1
remote message caught: Using setInternal 2
Using this.wait 2
Using this.wait 3
All done.
$
Problem
I need to make a loop of 3 times and 2 seconds in between each iteration. I tried these 3 options: Option 1 ``` var casper = require('casper').create({ verbose: false, logLevel: 'debug' }); casper.start("http://google.com"); casper.on('remote.message', function(msg) { this.echo('remote message caught: ' + msg); }) casper.thenEvaluate(function() { var x = 0; var intervalID = setInterval(function () { console.log("Using setInternal " + x); if (++x === 3) { window.clearInterval(intervalID); } }, 2000); }); casper.run(); ``` Observation: Nothing appeared because the script ended right away before the first `setInterval` being called. Option 2 Replaced `thenEvaluate()` with `then()` below ``` for (i=0; i<3; i++) { this.wait(2000); this.echo('Using this.wait ' + i); } ``` Observation: It outputs 3 times right away and then a long wait since `this.wait()` is async. This is not what I want because I want a delay in between. Option 3 Replace the part in `then()` with this below. I was thinking about doing a recursive call to `waitFunc()` after each `wait()` being called. ``` var count = 0; var waitFunc = function() { this.wait(2000, function() { if (count < 3) { casper.echo('Using this.wait ' + count); count++; waitFunc(); } }); }; ``` Observation: Nothing printed out on the screen. So my question is: How to make this.wait or setInterval works in a loop of 3 times like this case?