HackerNews API: What if HN does not have API? Make API on the fly with APIfy

http://apify.heroku.com/resources/4fca535156983f0001000002

by sathish316 • 14 years ago

132 49 14 years ago

apify.heroku.com

sathish31615• 14 years ago

Hacker News content is expired every 1 hour.

Hacker New Newest links are also available here: http://apify.heroku.com/resources/4fca651b8526fe0001000002

Other APIs are never expired (Expire feature is still not pushed)

jc4p• 14 years ago

Is it broken right now? It just says "API call failed: Internal Server Error" when I hit Test API.

There's also a good API which powers my favorite Android HN app over here: http://hndroidapi.appspot.com/

sathish31615• 14 years ago

I just fixed it. Someone removed an attribute by mistake.

sathish31615• 14 years ago

If you're creating APIs, please add Attributes. To get quick help on css or xpath selectors for attributes press c or x in site.

Jd2• 14 years ago

My problem with HackerNews API (having done something like this -- the Hacker News Filter on Github) is that you get throttled after you hit a certain number of HTTP requests and your IP gets banned for a certain amount of time.

So as nice as this is, it simply won't work here for the many people who would like to use near live data on HN.

sathish31615• 14 years ago

The page contents are cached and page is fetched every 1 hour. In fact cache is expired only for HackerNews API from the backend. Expiry feature is still not pushed

Jd2• 14 years ago

Might be the best you can do but the problem still exists.

roycyang2• 14 years ago

Looks interesting. I just tried to scrap a sample API but got an error with no further information on why it was broken:

http://apify.heroku.com/resources/4fca83088526fe000100011a/e...

roycyang2• 14 years ago

After playing around with it some more, it's working. Question, are you going to introduce REGEX or any other rules or even some helper functions to further process the API? That would allow us to drill down even further. It is really great for bootstrapping and getting some live data quickly. Kudos!

sathish31615• 14 years ago

Regex is not yet pushed to the webapp. Regex support is available in the gem used by APIfy https://github.com/sathish316/scrapify

altano• 14 years ago

Can you add support for CORS (http://en.wikipedia.org/wiki/Cross-origin_resource_sharing)?

Can you add support for taking existing JSON API (rather than scraping HTML)? This useful for APIs that are neither accessible with CORS nor JSONP, APIs that are provided by incompetent mental midgets who don't answer emails or participate to their Google Group (cough MBTA cough).

sathish31615• 14 years ago

If i understood correctly JSONP supports only GET but CORS supports all http methods. APIfy can only provide GET Requests (Index and Show) over a static html page

cheeaun• 14 years ago

That's one of the advantages of CORS. The other advantage is it allows cross-domain XMLHttpRequest requests in the browser, which will have better error handling than JSONP.

Trindaz• 14 years ago

Is this related to http://www.apifydoc.com/?

sathish31615• 14 years ago

It's not related. APIfy is a web frontend for a small library i've written to scrap webpages

https://github.com/sathish316/scrapify.

The advantage of the app over the library is caching and automatic expiry

pg• 14 years ago

HN does have an API: http://www.hnsearch.com/api

sathish31615• 14 years ago

The original intent of this app was not HN. It was smaller datasets like govt, public service and transit sites which generally don't have any APIs.

wslh• 14 years ago

And you can avoid HNSearch API limits with: https://gist.github.com/1360455

pbiggar• 14 years ago

I wish HN had a API which could write - the hnsearch one was only read-only when I used it. I tried writing a tool for HN (https://github.com/pbiggar/hackerite) that needed to be able to upvote stories, and although hacks existed to make it work, it wasn't a very pleasant experience.

DanielRibeiro2• 14 years ago

We have had an HN API for a while now: http://api.ihackernews.com/

zainny• 14 years ago

This API is extremely unreliable and has a great deal of functionality missing as well (commenting, voting). The original developer is also no longer maintaining it. I tried to build an Hacker News app using it some time ago and abandoned the idea very quickly.

Hacker News needs a real API.

DanielRibeiro2• 14 years ago

I have been using it for a few years now. It does give a error quite often (1 out of 10 requests on average), but for what I'm using, it is pretty solid (as long as I retry when these errors occur).

The lack of functionality: it had it. The problem is that it not only required user/password, but it also was caught into HN's safety net, that prevents multiple accounts from the same IP to do a lot of stuff.

So it can work as library, but not as a server-side API. Therefore he removed it.

For another project of mine[1], I used Hacker News search API[2], which is really consistent, and really powerful, and is maintained by the the yc company that does ThriftDB[3]

[1]http://hnwho.com/

[2] http://www.hnsearch.com/api

[3] http://venturebeatprofiles.com/news/view/y-combinator?articl...

ronnier• 14 years ago

The reason that it's so unreliable is that my server's IP address gets banned by YC when the requests are to fast, and I have it hosted on a small cheap server. There are ways around this, but it just isn't worth the time or money.

sinzone2• 14 years ago

would be cool if all the APIs created via APIfy are automatically listed into Mashape.com

sathish31615• 14 years ago

Somebody created an API in APIfy to list all APIfy APIs. Recursive and awesome. I just need to fix and make it work.

sinzone2• 14 years ago

cool - let me know when it's ready

fizx2• 14 years ago

Hah! tectonic and I applied to YC with almost exactly this in 2009?!

We went as far as building a browser-based IDE-like environment for generating these, and a language called parsley for expressing the scrapes. If you're interested in this, you could check out some of our related open source libraries:

Edit: I just open-sourced the scraping wiki site we created here: https://github.com/fizx/parselets_com

http://selectorgadget.com

https://github.com/fizx/parsley

https://github.com/fizx/parsley-ruby

https://github.com/fizx/pyparsley

https://github.com/fizx/csvget

    > cat hn.let
    {
      "headlines":[{
        "title": ".title a",
        "link": ".title a @href",
        "comments": "match(.subtext a:nth-child(3), '\\d+')",
        "user": ".subtext a:nth-child(2)",
        "score": "match(.subtext span, '\\d+')",
        "time": "match(.subtext, '\\d+\\s+\\w+\\s+ago')"
      }]
    }
    > csvget --directory-prefix=./data  -A "/x" -w 5 --parselet=hn.let http://news.ycombinator.com/
    > head data/headlines.csv
    comments,title,time,link,score,user
    4,Simpson's paradox: why mistrust seemingly simple statistics,2 hours ago,http://en.wikipedia.org/wiki/Simpson%27s_paradox,41,waldrews
    67,America's unjust sex laws,2 hours ago,http://www.economist.com/opinion/displaystory.cfm?story_id=14165460,59,MikeCapone
    23,Buy somebody lunch,3 hours ago,http://www.whattofix.com/blog/archives/2009/08/buy-somebody-lu.php,58,DanielBMarkham

sc00ter• 14 years ago

Oh! Selector gadget is wonderful, and I still use it to this day. It's so easy to forget that there are real people behind the tools we use - so fizx and tectonic, I thank you!

christiangenco• 14 years ago

Seconded - selector gadget is one of the best scraping tools around. You've saved me many a frustrated evenings.

tectonic2• 14 years ago

Thanks for the kind words! Maybe this attention will push me to update the code and make a new screencast.

sathish31615• 14 years ago

Do you mind if i use selector gadget in APIfy? I use firebug and firefinder to get selectors. But i can't expect everyone to have the same tools.

fizx2• 14 years ago

Everything mentioned is MIT-licensed, and like many OSS authors, we would love any ideas or code in there to be widely used in virtually any capacity.

Also, if you're in or near SF, I'd be happy to get coffee sometime.

tluyben22• 14 years ago

I was going to suggest here that you do. And opensource your creation on github so we can all improve it.

tectonic2• 14 years ago

Please do use selectorgadget! And if you'd like to push anything back, or chat about parsing in general, send me a message. I have a more advanced branch of SG that can generate better selectors, but I haven't pushed it out yet. It's all in the repo.

tluyben22• 14 years ago

Selectorgadget is great; without checking out your creations in real life, did you consider taping selectorgadget to a proxy so you can scrape sites and store the paths you found in one go? That would massively enhance the process imho :) Maybe Apify can do that, but I hope they put that in github as well; i'm not a great fan of closed source/cloud development tools.

zafriedman• 14 years ago

This might be a stupid question and perhaps I didn't look hard enough on your website, but is this open source? I didn't see a GitHub link anywhere. I'm specifically curious as to how you routed Noko or whatever scraping library you're using to do its thing.

sathish31615• 14 years ago

The webapp is not open source. But the underlying library Scrapify is open source. It internally uses Nokogiri if that's what your question.

https://github.com/sathish316/scrapify#readme

temphn• 14 years ago

Does this work for sites that are behind logins? Didn't see anything related to authentication but may have missed it.

sathish31615• 14 years ago

There is no authentication mechanism right now. Only public sites are supported

gildas2• 14 years ago

Does not work with twitter [1].

"API call failed: Internal Server Error"

[1] http://apify.heroku.com/resources/4fcb23c5a06a160001000014

sathish31615• 14 years ago

If html content is loaded using ajax, you have to give the URL of the Ajax request html. See http://apify.heroku.com/resources/4fc2a234ae684d0001000008/e... for example.

It won't work for #! URLs. Twitter has a nice streaming API for search if that's what you're looking for.

gildas2• 14 years ago

* Ajax responses are often JSON content. How do I apply a CSS/XPath selector on it?

* I guess #! URLs could be transformed into _escaped_fragment_ URLs [1]

* I know twitter has an API. It was just an example. Maybe this example [2] would be more relevant (content could also be fetched with an _escaped_fragment_ URL).

[1] https://developers.google.com/webmasters/ajax-crawling/docs/...

[2] http://apify.heroku.com/resources/4fcb2f7ba06a160001000044

6ren2• 14 years ago

You need to specify a unique index for the attribute - you specified it as "tweet", but not how to scrape it. The error messages are not informative at this stage; it might be something else too.

I tried to fix your e.g. but couldn't get it to work (I tried //span@data-time (xpath) - what is the unique index of a tweet?)

6ren2• 14 years ago

Seems to be fried. (Popularity is a good sign.)

So, it's basically a web-scraper, but with a JSON API. The API input is limited to a single parameter, that indexes the record to be scraped. The API output is taken from that indexed record, consisting of a set of scraped elements within that record, and presented as JSON, with attributes named as user specified.

Although this is limited to a list of renamed records, it could be extended (if needed), and I really like the concept and UI implementation. Feedback: As someone who has never used css, I found it very tricky to even duplicate the tutorial: selectors are sensitive to leading and trailing spaces; the selectors given in the tute aren't what's needed (and see BTW below); and often "API call failed: Internal Server Error" indicating a problem with the selector, but not what it is, and ATM service is often "unavailable" :), it's slow switching back and forth between "edit" and "test" (why not include testing on the same page? like HN comment edits: textarea + rendered result); when an attribute is removed, it remains in the JSON (code eg http://apify.heroku.com/resources/4fcb26d7a06a160001000024); it takes a long time (30s, 1min) to get a result. I hate to say it, but it's like my experience with ruby: it takes so much time and effort to get the tool to basically work, that I've used up all my enthusiasm/gumption and have none left for the project I had in mind. But much of this is because of current traffic spike, my ignorance of css, and minor polishing/bugs that can be fixed in vers 1.1 - as I said, I really like the idea and UI.

But a deeper question: why a service, instead of a library? It's cross-language, but has an extra dependency (the service), an extra network jump, processing from many users convening at one point. It's interesting to me, because the world seems to be moving towards services, and this would logically include components that formerly would be libraries. Will this happen? What are the pros and cons? Will Amazon etc provide free computation for users of open-source components, analogous to open-source libraries? Interesting.

BTW: minor typo/bug in active URLs in the tute (http://apify.heroku.com/tutorial/create): an extra "s" in "episodess":

  http://apify.heroku.com/api/big_bang_theory_episodess.json
  http://apify.heroku.com/api/big_bang_theory_episodess/5.json

sathish31615• 14 years ago

Thanks for the feedback. Will fix it in a future version.

Service is just an extension of this library:

https://github.com/sathish316/scrapify

The intent of service is to make mobile apps without a backend/db like Parse for read only APIs

premasagar• 14 years ago

Did anyone ever make an API that could read a user's upvoted/saved articles from HN? It would require some kind of login credentials, as the data is not public.

sktrdie• 14 years ago

Simply record the HTTP requests happening when you access that page. You probably have to pass the Cookie along through the header for the credentials to work.

But it's just HTTP, so it's basically already an API.

HackerNews API: What if HN does not have API? Make API on the fly with APIfy

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