Ajax Crawling with PHP and Curl?
I apologise now if I put off some of the more general readers with this post, but I’ve struck upon a bit a problem!
I have some automated code that I wrote using PHP and Curl, that retrieves a mountain of information from a website, does some statistical analysis on it and then presents me with a nice little report (having inserted the data into a MySQL database). It’s wonderful – to do the process manually would take maybe 2-3 hours every day, as it is I wake up to a nice report sat in my inbox everyday with all the information in it.
Now I have a problem, the website that I crawl to get this information is converting to Ajax – this presents me with a huge problem……
Web Spiders
Web spiders for the most part, grab a page from a server, make a list of links in the page and then go off and repeat the process on all those links it’s found (each one triggering a different database or variable call in a website).
Ajax isn’t quite so easy, most of the page isn’t even in the HTML! It’s inserted after by javascript – mostly when the user clicks something, meaning the user doesn’t even navigate to a different page, but actually stays on the same page and lets the javascript refresh (hence our crawler can’t make a list of the links!). Some websites allow for this having a “lite” version, the one I’m using doesn’t 
Thinking like a Human
We need to make our crawler think and act like a human – sounds easy enough right? You’ve written a crawler before surely you can do that?
Wrong! I can’t think of any logical way to get PHP to do this for me!
Any crawler process would need to be able to see events and states in the document that a real user might click on.
Some reading around this problem (and believe me, I have), suggests that the easiest way of possible of doing this is to create an AJAX-enabled event-driven reader. Heck we use one of these everyday of the week (it’s your web browser folks, whether it be IE, Firefox, Opera, Safari etc. etc.).
Using the Browser
FleshEater There are a couple of tools around that seem to use the browser, Watir (using Ruby) and Crowbar (which uses a mozilla based browser).
Does anyone have any other bright ideas before I spend hours fighting with yet another new technology?
{ 9 comments… read them below or add one }
I briefly Tweeted about the possibility of using a synthetic transaction tool to do this, but I think you’re already thinking along those lines with the tools you’ve linked to.
There may be better GUI-driven tools around, but it may be a case of what are you willing to pay for?
In the meantime, looks like you might be off to Ruby school!
I’ve tried the Crowbar approach with a little success, but can’t achieve exactly what I want. The problem is I need to be able to write this to be completely automated, with no intervention! And then it needs to be able to insert the data in a database for analysis later as well
I’m willing to pay for it, if it can achieve all of those things!
Did you already succeed in doing this?
Yes, after a fashion!
So what do you use now to get this done? Watir or still Crowbar? Could you try to teach the general steps?
thanks, i am actually at the same contest.
I forget how the code works now, but it did what I needed in the end!
We’ve just launched http://www.office-automation.co.uk based on feedback from clients on that sort of work, if you’ve got something you’d like us to take a look at then let me know?
wow, that was really useless. bookmark killed
lol, as you may have noted:
I’ll go looking for the code when I’m on my own machine and see if I can make a generic enough post about it to fit most scenarios!
That said, I have just launched Office Automation because there are a lot of people out there who could use this sort of functionality and don’t have the coding skills to make their lives easier!
Looking back at the code that’s running in the cron job I think I implemented almost entirely in Curl and it worked!
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