The contents of a commerce website (ASP.NET MVC) are regularly crawled by the competition. These people are programmers and they use sophisticated methods to crawl the site so identifying them by IP is not possible.
Unfortunately replacing values with images is not an option because the site should still remain readable by screen readers (JAWS).
My personal idea is using robots.txt: prohibit crawlers from accessing one common URL on the page (this could be disguised as a normal item detail link, but hidden from normal users Valid URL: http://example.com?itemId=1234 Prohibited: http://example.com?itemId=123 under 128). If an IP owner entered the prohibited link show a CAPTCHA validation.
A normal user would never follow a link like this because it is not visible, Google does not have to crawl it because it is bogus. The issue with this is that the screen reader still reads the link and I don't think that this would be so effective to be worth implementing.
Your idea could possibly work for a few basic crawlers but would be very easy to work around. They would just need to use a proxy and do a get on each link from a new IP.
If you allow anonymous access to your website then you can never fully protect your data. Even if you manage to prevent crawlers with lots of time and effort they could just get a human to browse and capture the content with something like fiddler. The best way to prevent your data being seen by your competitors would be to not put it on a public part of your website.
Forcing users to log in might help matters, at least then you could pick up who is crawling your site and ban them.
As mentioned, its not really going to be possible to hide publicly accessible data from a determined user, however, as these are automated crawlers, you could make life harder for them by altering the layout of your page regularly.
It is probably possible to use different master pages to produce the same (or similar) layouts, and you could swap in the master page on a random basis - this would make the writing of an automated crawler that bit more difficult.
I am about to get to the phase of protecting my content from crawlers either.
I am thinking of limiting what an anonymous user can see of the website and require them to register for a full functionality.
example:
public ActionResult Index()
{
if(Page.User.Identity.IsAuthorized)
return RedirectToAction("IndexAll");
// show only some poor content
}
[Authorize(Roles="Users")]
public ActionResult IndexAll()
{
// Show everything
}
Since you know users now, you can punish any crawler.
Related
Assuming it's not available as part of API, how can one obtain a full or partial list of public users of a web service, e.g. Twitter, Tumblr, YouTube?
Acceptable alternative: get a random public user.
I was interested in this for testing APIs with a random account. This is useful to catch edge cases when developing an app for the API; For example when developing a Tumblr theme, seeing what volumes of text/images are posted, special character use, and so on.
Can you even imagine a full list of (public) users of largely used web services? That's a vast load of data. I hardly believe that any API would offer that for many reasons:
performance/load issues,
data/information privacy,
abusing possibilities,...
For regular usage of the service's API you simply don't need that. Otherwise it would stink with some gray/black techniques.
Anyway to answer you question objectively: In order to get full or partial list of users from web service it have to provide any kind of API which would allow you to do that. So good starting point is to look at documentation, for example Twitter API, Youtube API, etc...
By swift look I don't see any method that would offer that. It might change in the future but as mentioned above I strongly doubt about that.
Another option is to mine partial list of users via search APIs or traversing the site with a robot. Also obtaining such a list is an option. However I would check whether this is even legal and not against terms of use or something like that.
I'm building a service where people gets notified (mails) when they follow a link with the format www.domain.com/this_is_a_hash. The people that use this server can share this link on different places like, twitter, tumblr, facebook and more...
The main problem I'm having is that as soon as the link is shared on any of this platforms a lot of request to the www.domain.com/this_is_a_hash are coming to my server. The problem with this is that each time one of this requests hits my server a notification is sent to the owner of the this_is_a_hash, and of course this is not what I want. I just want to get notifications when real people is going into this resource.
I found a very interesting article here that talks about the huge amount of request a server receives when posting to twitter...
So what I need is to avoid search engines to hit the "resource" url... the www.mydomain.com/this_is_a_hash
Any idea? I'm using rails 3.
Thanks!
If you don’t want these pages to be indexed by search engines, you could use a robots.txt to block these URLs.
User-agent: *
Disallow: /
(That would block all URLs for all user-agents. You may want to add a folder to block only those URLs inside of it. Or you could add the forbidden URLs dynamically as they get created, however, some bots might cache the robots.txt for some time so they might not recognize that a new URL should be blocked, too.)
It would, of course, only hold back those bots that are polite enough to follow the rules of your robots.txt.
If your users would copy&paste HTML, you could make use of the nofollow link relationship type:
cute cat
However, this would not be very effective, as even some of those search engines that support this link type still visit the pages.
Alternatively, you could require JavaScript to be able to click the link, but that’s not very elegant, of course.
But I assume they only copy&paste the plain URL, so this wouldn’t work anyway.
So the only chance you have is to decide if it’s a bot or a human after the link got clicked.
You could check for user-agents. You could analyze the behaviour on the page (e.g. how long it takes for the first click). Or, if it’s really important to you, you could force the users to enter a CAPTCHA to be able to see the page content at all. Of course you can never catch all bots with such methods.
You could use analytics on the pages, like Piwik. They try to differentiate users from bots, so that only users show up in the statistics. I’m sure most analytics tools provide an API that would allow sending out mails for each registered visit.
I would like to test if the user's browser window.width is >= 800px
if so i would like to render partial A otherwise if window.width >= 800px.
I have little experience, please explain my options on implementation:
I am expecting either a javascript method on the page or jQuery.
I have tried
http://scottwb.com/blog/2012/02/23/a-better-way-to-add-mobile-pages-to-a-rails-site/
but
1. it doesn't work for me.
2. even if it did I expect it will work based on device being used, not pixel count.
Thank you in advance!
You could use Ahoy. The current_visit method contains the following information.
When someone visits your website, Ahoy creates a visit with lots of
useful information.
traffic source - referrer, referring domain, landing page, search
keyword location - country, region, and city
technology - browser, OS,
and device type
utm parameters - source, medium, term, content,
campaign
A request won't contain data about screen size, so in common sense the sever has no way to know what is screen width and what response to serve, as PinnyM also mentioned in comment.
A general practice is to use User Agent to detect mobile device from server. User Agent is part of request. It's not 100% accurate, but it's something you could still depend on for most cases.
However, there is still solutions for your question - serve page based on screen size.
The workaround is to use Javascript to detect screen size at first, then use JS to drop a cookie. Server is able to read the cookie and decide which template to render.
The basic repo is here: https://github.com/mattstauffer/Simple-RESS It's for PHP, but you can get the idea from the source code.
There is also Rails implementation: https://github.com/matthewrobertson/ress, and the introduction: http://matthewrobertson.org/blog/2013/02/15/introducing-ress/
My opinion: I don't like this solution though it is viable. Lots of works to do and lots of things to taking care of. I would rather user User Agent detect instead.
Sounds like using a responsive front end framework might be something to look into. I'm a big fan of Foundation, it's super easy to use it with Rails apps. And the new version of Foundation just launched today! Check it out: http://foundation5.zurb.com/
I've just noticed that the long, convoluted Facebook URLs that we're used to now look like this:
http://www.facebook.com/example.profile#!/pages/Another-Page/123456789012345
As far as I can recall, earlier this year it was just a normal URL-fragment-like string (starting with #), without the exclamation mark. But now it's a shebang or hashbang (#!), which I've previously only seen in shell scripts and Perl scripts.
The new Twitter URLs now also feature the #! symbols. A Twitter profile URL, for example, now looks like this:
http://twitter.com/#!/BoltClock
Does #! now play some special role in URLs, like for a certain Ajax framework or something since the new Facebook and Twitter interfaces are now largely Ajaxified?
Would using this in my URLs benefit my Web application in any way?
This technique is now deprecated.
This used to tell Google how to index the page.
https://developers.google.com/webmasters/ajax-crawling/
This technique has mostly been supplanted by the ability to use the JavaScript History API that was introduced alongside HTML5. For a URL like www.example.com/ajax.html#!key=value, Google will check the URL www.example.com/ajax.html?_escaped_fragment_=key=value to fetch a non-AJAX version of the contents.
The octothorpe/number-sign/hashmark has a special significance in an URL, it normally identifies the name of a section of a document. The precise term is that the text following the hash is the anchor portion of an URL. If you use Wikipedia, you will see that most pages have a table of contents and you can jump to sections within the document with an anchor, such as:
https://en.wikipedia.org/wiki/Alan_Turing#Early_computers_and_the_Turing_test
https://en.wikipedia.org/wiki/Alan_Turing identifies the page and Early_computers_and_the_Turing_test is the anchor. The reason that Facebook and other Javascript-driven applications (like my own Wood & Stones) use anchors is that they want to make pages bookmarkable (as suggested by a comment on that answer) or support the back button without reloading the entire page from the server.
In order to support bookmarking and the back button, you need to change the URL. However, if you change the page portion (with something like window.location = 'http://raganwald.com';) to a different URL or without specifying an anchor, the browser will load the entire page from the URL. Try this in Firebug or Safari's Javascript console. Load http://minimal-github.gilesb.com/raganwald. Now in the Javascript console, type:
window.location = 'http://minimal-github.gilesb.com/raganwald';
You will see the page refresh from the server. Now type:
window.location = 'http://minimal-github.gilesb.com/raganwald#try_this';
Aha! No page refresh! Type:
window.location = 'http://minimal-github.gilesb.com/raganwald#and_this';
Still no refresh. Use the back button to see that these URLs are in the browser history. The browser notices that we are on the same page but just changing the anchor, so it doesn't reload. Thanks to this behaviour, we can have a single Javascript application that appears to the browser to be on one 'page' but to have many bookmarkable sections that respect the back button. The application must change the anchor when a user enters different 'states', and likewise if a user uses the back button or a bookmark or a link to load the application with an anchor included, the application must restore the appropriate state.
So there you have it: Anchors provide Javascript programmers with a mechanism for making bookmarkable, indexable, and back-button-friendly applications. This technique has a name: It is a Single Page Interface.
p.s. There is a fourth benefit to this technique: Loading page content through AJAX and then injecting it into the current DOM can be much faster than loading a new page. In addition to the speed increase, further tricks like loading certain portions in the background can be performed under the programmer's control.
p.p.s. Given all of that, the 'bang' or exclamation mark is a further hint to Google's web crawler that the exact same page can be loaded from the server at a slightly different URL. See Ajax Crawling. Another technique is to make each link point to a server-accessible URL and then use unobtrusive Javascript to change it into an SPI with an anchor.
Here's the key link again: The Single Page Interface Manifesto
First of all: I'm the author of the The Single Page Interface Manifesto cited by raganwald
As raganwald has explained very well, the most important aspect of the Single Page Interface (SPI) approach used in FaceBook and Twitter is the use of hash # in URLs
The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.
In spite of #! combination is very interesting for SEO, is only supported by Google (as far I know), with some JavaScript tricks you can build SPI web sites SEO compatible for any web crawler (Yahoo, Bing...).
The SPI Manifesto and demos do not use Google's format of ! in hashes, this notation could be easily added and SPI crawling could be even easier (UPDATE: now ! notation is used and remains compatible with other search engines).
Take a look to this tutorial, is an example of a simple ItsNat SPI site but you can pick some ideas for other frameworks, this example is SEO compatible for any web crawler.
The hard problem is to generate any (or selected) "AJAX page state" as plain HTML for SEO, in ItsNat is very easy and automatic, the same site is in the same time SPI or page based for SEO (or when JavaScript is disabled for accessibility). With other web frameworks you can ever follow the double site approach, one site is SPI based and another page based for SEO, for instance Twitter uses this "double site" technique.
I would be very careful if you are considering adopting this hashbang convention.
Once you hashbang, you can’t go back. This is probably the stickiest issue. Ben’s post put forward the point that when pushState is more widely adopted then we can leave hashbangs behind and return to traditional URLs. Well, fact is, you can’t. Earlier I stated that URLs are forever, they get indexed and archived and generally kept around. To add to that, cool URLs don’t change. We don’t want to disconnect ourselves from all the valuable links to our content. If you’ve implemented hashbang URLs at any point then want to change them without breaking links the only way you can do it is by running some JavaScript on the root document of your domain. Forever. It’s in no way temporary, you are stuck with it.
You really want to use pushState instead of hashbangs, because making your URLs ugly and possibly broken -- forever -- is a colossal and permanent downside to hashbangs.
To have a good follow-up about all this, Twitter - one of the pioneers of hashbang URL's and single-page-interface - admitted that the hashbang system was slow in the long run and that they have actually started reversing the decision and returning to old-school links.
Article about this is here.
I always assumed the ! just indicated that the hash fragment that followed corresponded to a URL, with ! taking the place of the site root or domain. It could be anything, in theory, but it seems the Google AJAX Crawling API likes it this way.
The hash, of course, just indicates that no real page reload is occurring, so yes, it’s for AJAX purposes. Edit: Raganwald does a lovely job explaining this in more detail.
I've just noticed that the long, convoluted Facebook URLs that we're used to now look like this:
http://www.facebook.com/example.profile#!/pages/Another-Page/123456789012345
As far as I can recall, earlier this year it was just a normal URL-fragment-like string (starting with #), without the exclamation mark. But now it's a shebang or hashbang (#!), which I've previously only seen in shell scripts and Perl scripts.
The new Twitter URLs now also feature the #! symbols. A Twitter profile URL, for example, now looks like this:
http://twitter.com/#!/BoltClock
Does #! now play some special role in URLs, like for a certain Ajax framework or something since the new Facebook and Twitter interfaces are now largely Ajaxified?
Would using this in my URLs benefit my Web application in any way?
This technique is now deprecated.
This used to tell Google how to index the page.
https://developers.google.com/webmasters/ajax-crawling/
This technique has mostly been supplanted by the ability to use the JavaScript History API that was introduced alongside HTML5. For a URL like www.example.com/ajax.html#!key=value, Google will check the URL www.example.com/ajax.html?_escaped_fragment_=key=value to fetch a non-AJAX version of the contents.
The octothorpe/number-sign/hashmark has a special significance in an URL, it normally identifies the name of a section of a document. The precise term is that the text following the hash is the anchor portion of an URL. If you use Wikipedia, you will see that most pages have a table of contents and you can jump to sections within the document with an anchor, such as:
https://en.wikipedia.org/wiki/Alan_Turing#Early_computers_and_the_Turing_test
https://en.wikipedia.org/wiki/Alan_Turing identifies the page and Early_computers_and_the_Turing_test is the anchor. The reason that Facebook and other Javascript-driven applications (like my own Wood & Stones) use anchors is that they want to make pages bookmarkable (as suggested by a comment on that answer) or support the back button without reloading the entire page from the server.
In order to support bookmarking and the back button, you need to change the URL. However, if you change the page portion (with something like window.location = 'http://raganwald.com';) to a different URL or without specifying an anchor, the browser will load the entire page from the URL. Try this in Firebug or Safari's Javascript console. Load http://minimal-github.gilesb.com/raganwald. Now in the Javascript console, type:
window.location = 'http://minimal-github.gilesb.com/raganwald';
You will see the page refresh from the server. Now type:
window.location = 'http://minimal-github.gilesb.com/raganwald#try_this';
Aha! No page refresh! Type:
window.location = 'http://minimal-github.gilesb.com/raganwald#and_this';
Still no refresh. Use the back button to see that these URLs are in the browser history. The browser notices that we are on the same page but just changing the anchor, so it doesn't reload. Thanks to this behaviour, we can have a single Javascript application that appears to the browser to be on one 'page' but to have many bookmarkable sections that respect the back button. The application must change the anchor when a user enters different 'states', and likewise if a user uses the back button or a bookmark or a link to load the application with an anchor included, the application must restore the appropriate state.
So there you have it: Anchors provide Javascript programmers with a mechanism for making bookmarkable, indexable, and back-button-friendly applications. This technique has a name: It is a Single Page Interface.
p.s. There is a fourth benefit to this technique: Loading page content through AJAX and then injecting it into the current DOM can be much faster than loading a new page. In addition to the speed increase, further tricks like loading certain portions in the background can be performed under the programmer's control.
p.p.s. Given all of that, the 'bang' or exclamation mark is a further hint to Google's web crawler that the exact same page can be loaded from the server at a slightly different URL. See Ajax Crawling. Another technique is to make each link point to a server-accessible URL and then use unobtrusive Javascript to change it into an SPI with an anchor.
Here's the key link again: The Single Page Interface Manifesto
First of all: I'm the author of the The Single Page Interface Manifesto cited by raganwald
As raganwald has explained very well, the most important aspect of the Single Page Interface (SPI) approach used in FaceBook and Twitter is the use of hash # in URLs
The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.
In spite of #! combination is very interesting for SEO, is only supported by Google (as far I know), with some JavaScript tricks you can build SPI web sites SEO compatible for any web crawler (Yahoo, Bing...).
The SPI Manifesto and demos do not use Google's format of ! in hashes, this notation could be easily added and SPI crawling could be even easier (UPDATE: now ! notation is used and remains compatible with other search engines).
Take a look to this tutorial, is an example of a simple ItsNat SPI site but you can pick some ideas for other frameworks, this example is SEO compatible for any web crawler.
The hard problem is to generate any (or selected) "AJAX page state" as plain HTML for SEO, in ItsNat is very easy and automatic, the same site is in the same time SPI or page based for SEO (or when JavaScript is disabled for accessibility). With other web frameworks you can ever follow the double site approach, one site is SPI based and another page based for SEO, for instance Twitter uses this "double site" technique.
I would be very careful if you are considering adopting this hashbang convention.
Once you hashbang, you can’t go back. This is probably the stickiest issue. Ben’s post put forward the point that when pushState is more widely adopted then we can leave hashbangs behind and return to traditional URLs. Well, fact is, you can’t. Earlier I stated that URLs are forever, they get indexed and archived and generally kept around. To add to that, cool URLs don’t change. We don’t want to disconnect ourselves from all the valuable links to our content. If you’ve implemented hashbang URLs at any point then want to change them without breaking links the only way you can do it is by running some JavaScript on the root document of your domain. Forever. It’s in no way temporary, you are stuck with it.
You really want to use pushState instead of hashbangs, because making your URLs ugly and possibly broken -- forever -- is a colossal and permanent downside to hashbangs.
To have a good follow-up about all this, Twitter - one of the pioneers of hashbang URL's and single-page-interface - admitted that the hashbang system was slow in the long run and that they have actually started reversing the decision and returning to old-school links.
Article about this is here.
I always assumed the ! just indicated that the hash fragment that followed corresponded to a URL, with ! taking the place of the site root or domain. It could be anything, in theory, but it seems the Google AJAX Crawling API likes it this way.
The hash, of course, just indicates that no real page reload is occurring, so yes, it’s for AJAX purposes. Edit: Raganwald does a lovely job explaining this in more detail.