casperjs-link-checker.md

A CasperJS link checker

A simple CasperJS script to periodically check for a link and process accordingly.

/*jshint strict:false*/
/*global CasperError console phantom require*/
var casper = require('casper').create({
        logLevel: "debug",
        verbose: true
    }),
    interval = 1000 * 60,       // 1 minute
    url = 'http://google.com/'; // URL to check

casper.checkLink = function checkLink() {
    this.echo('Setting up check steps...');
    this.open(url).then(function() {
        if (this.exists('#selector-to-your-link')) {
            this.echo('link was found, clicking');
            this.thenClick('#selector-to-your-link').then(function() {
                // add stuff to be done
                // ... then exit
                this.echo('Done.').exit();
            });
        } else {
            this.warn('Link not found, scheduling another attempt');
            this.wait(interval);
        }
    });
    this.run(this.checkLink);
};

casper.start().checkLink();

Sample output:

$ casperjs waiter.js
[info] [phantom] Starting...
Setting up check steps...
[debug] [phantom] opening url: http://google.com/, HTTP GET
[debug] [phantom] Navigation requested: url=http://google.com/, type=Other, lock=true, isMainFrame=true
[info] [phantom] Running suite: 1 step
[debug] [phantom] Navigation requested: url=http://www.google.com/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] Navigation requested: url=http://www.google.fr/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] url changed to "http://www.google.fr/"
[debug] [phantom] Successfully injected Casper client-side utilities
[info] [phantom] Step 1/1 http://www.google.fr/ (HTTP 301)
[warning] [phantom] Link not found, scheduling another attempt
⚠  Link not found, scheduling another attempt
[info] [phantom] Step 1/1: done in 1265ms.
[info] [phantom] Step 2/2 http://www.google.fr/ (HTTP 301)
[info] [phantom] Step 2/2: done in 1364ms.
[info] [phantom] wait() finished waiting for 10000ms.
[info] [phantom] Done 2 steps in 11387ms
Setting up check steps...
[debug] [phantom] opening url: http://google.com/, HTTP GET
[debug] [phantom] Navigation requested: url=http://google.com/, type=Other, lock=true, isMainFrame=true
[info] [phantom] Running suite: 3 steps
[debug] [phantom] Navigation requested: url=http://www.google.com/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] Navigation requested: url=http://www.google.fr/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] url changed to "http://www.google.fr/"
[debug] [phantom] Successfully injected Casper client-side utilities
[info] [phantom] Step 3/3 http://www.google.fr/ (HTTP 301)
[warning] [phantom] Link not found, scheduling another attempt
⚠  Link not found, scheduling another attempt
[info] [phantom] Step 3/3: done in 11896ms.
[info] [phantom] Step 4/4 http://www.google.fr/ (HTTP 301)
[info] [phantom] Step 4/4: done in 11992ms.
[info] [phantom] wait() finished waiting for 10000ms.
[info] [phantom] Done 4 steps in 22015ms
Setting up check steps...
[debug] [phantom] opening url: http://google.com/, HTTP GET
[debug] [phantom] Navigation requested: url=http://google.com/, type=Other, lock=true, isMainFrame=true
[info] [phantom] Running suite: 5 steps
[debug] [phantom] Navigation requested: url=http://www.google.com/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] Navigation requested: url=http://www.google.fr/, type=Other, lock=true, isMainFrame=true
[debug] [phantom] url changed to "http://www.google.fr/"
[debug] [phantom] Successfully injected Casper client-side utilities
[info] [phantom] Step 5/5 http://www.google.fr/ (HTTP 301)
[warning] [phantom] Link not found, scheduling another attempt
⚠  Link not found, scheduling another attempt
[info] [phantom] Step 5/5: done in 22525ms.
[info] [phantom] Step 6/6 http://www.google.fr/ (HTTP 301)
[info] [phantom] Step 6/6: done in 22622ms.
^C

waiter.js

/*jshint strict:false*/
/*global CasperError console phantom require*/
var casper = require('casper').create({
        logLevel: "debug",
        verbose: true
    }),
    interval = 1000 * 60,       // 1 minute
    url = 'http://google.com/'; // URL to check

casper.checkLink = function checkLink() {
    this.echo('Setting up check steps...');
    this.open(url).then(function() {
        if (this.exists('#selector-to-your-link')) {
            this.echo('link was found, clicking');
            this.thenClick('#selector-to-your-link').then(function() {
                // add stuff to be done
                // ... then exit
                this.echo('Done.').exit();
            });
        } else {
            this.warn('Link not found, scheduling another attempt');
            this.wait(interval);
        }
    });
    this.run(this.checkLink);
};

casper.start().checkLink();