
Show HN: A new way to diff websites - patrickrogers
http://www.diffd.com/?ref=hackernews
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saberworks
Looks cool. I wanted to build a service that would monitor an external web
page for me and notify me about content changes. The problem was that it was
constantly detecting changes with ads or menus or stuff not related to the
content itself (which is what I was interested in). Didn't have time to get it
going any further. One use case for me was to monitor the Washington State
traffic laws (or all RCWs if needed) and get notified when changes were
published (with a diff that I could actually read, as opposed to just the URL
with the change on it). I've found over the years that the laws were being
changed in very small ways (like a 1 character diff, like changing "2" days to
"5" days, giving LEOs more time to file traffic tickets with the court, or
just a few letters, like changing "may" to "must" (requiring judges to dismiss
tickets not filed in a timely manner as opposed to giving them the option).

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notgood
With CasperJS and a CSS selector it would be easy to do, a few lines actually:
[https://gist.github.com/Ivanca/aef2e58dbbf9eb3e1bd4](https://gist.github.com/Ivanca/aef2e58dbbf9eb3e1bd4)

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scott_karana
If you're not interested in this because it's SaaS, check out BBC's Wraith
instead:

[http://responsivenews.co.uk/post/56884056177/wraith](http://responsivenews.co.uk/post/56884056177/wraith)

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michaelstewart
Wraith is a cool open source project that we played around with a bunch before
starting Diffd. This is roughly what the same diff of Stripe as shown in our
demo will look like with Wraith:
[http://www.diffd.com/imagemagick_compare.png](http://www.diffd.com/imagemagick_compare.png)

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mrmondo
Nice, I've written a few scripts to do things like this such as creating heat
maps of areas of change between two sites and giving you the percentage of
difference for CI builds etc...

Do you have any plans to open source this? That's the big factor for a lot of
organisations decisions as to whether they'll make use of software or not. For
example we have a policy that we won't rely on any proprietary software within
our build / test pipeline.

~~~
michaelstewart
We have been considering going down that route and releasing Diffd as an open
source project while offering a hosted version that is the easiest way to do
things in parallel and across multiple browsers and operating systems.

However, we expect that initially most will add Diffd as a manual step at the
end of their pipeline. So, it's not like their ability to push code is
completely dependent on a third party, it's just another check.

Taking a dependence on Diffd is going to be less risky than depending on a
third party for your CI server like Travis CI, CircleCI or CodeShip.

~~~
mrmondo
We don't depend on a third party for our CI though? We use Gitlab-CI to build
all our code / Docker images and run our tests which not only works very well
but is also extremely fast.

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lazyant
Congrats on releasing, I was doing a similar thing, with a 'backup' twist but
never got to do the MVP [http://clicktwin.com/](http://clicktwin.com/)

~~~
michaelstewart
Thanks lazyant. Clicktwin looks cool, I think people might find the instant
deployment to s3 useful if they had a dynamic website that was falling over
from high load.

You might also be able to achieve a similar sort of backup with Cloudflare.

