如何不允许用户提交链接？ （html表格/ PHP / javascript）

Question

I have an idea for a website and I will be using a form to allow users to submit a text. The problem is that I don't want anyone to register(because I think that my idea is much more fun without registering as more people will use it) and by doing that I'm sure that people will spam the sh** out of my website.

My question is: What's the easiest way to prevent this from happening? It must be a really good way to block html code and any other pattern/tricks(spaces has to be filtered) spammers will use to submit links.. Of course I will use CAPTCHA to stop automated submission, my concern is about people manually submitting links.

Thanks in advance.

Answer 1

strip_tags should work for most cases. I personally favor using a more comprehensive library to handle user-submitted text. htmLawed is excellent for this purpose.

http://www.bioinformatics.org/phplabware/internal_utilities/htmLawed/index.php

Answer 2

You could also moderate submissions or use a spam filtering service. There quite are a few services out there that have APIs:

http://akismet.com/

http://mollom.com

http://antispam.typepad.com

Answer 3

using simple validation in complex ways can help you do whatever you want. Just pass the input through a function to do whatever you want.

function validate(i)
{
  var i = document.getElementById(i).value;
  if($i contins foo)
    {
      disable submit button
    }
}

<input type="text" id='url' onblur="validate(this.id)">
    <input type="submit" >