display external html list item in new page using php?

**esteeven** · October 4th, 2009

I am building a web page and, as is becoming increasingly routine for me, I have bitten off more than I can chew. I am even finding it hard to describe what I want to do

mypage.html needs to display (possibly random) items from a list on another website.

In my confused mind, I imagine the process like this (forgive the fake code : I had real problems displaying code on an earlier post )

externalpage.html

<html>

<li> item one
<li> item two
<li> item three

</html>

mypage.html

<html>
<div>
<php>
I want to display <li> item (possibly random) here
</php>
</div>
</html>

The list item display will be part of a page and not the whole page.

FYI : the person who has asked me to build this site does the following. They log on to externalpage.html and add items to the list (a photograph of a house and a description). mypage.html needs to display list items as examples of what is in the list. The full list is available using an iframe on mypage2.html.

When I agreed to help build the site, I thought it was all going to be html. I know to ask questions now

**NoaHall** · October 4th, 2009

First things first. Php is not declaired using <php> . It's <?php and ?>

What you want to do is

<?php echo "<li>" . $listitem . "</li>"; ?>

By external, do you mean the webpage on a completely different site?

**esteeven** · October 4th, 2009

Yes. You are right. My php tags were awful.

<?php echo "<li>"$listitem"</li>"; ?> This is exactly what I want to do, I think.

The list items that I want to display are on another website.

**Reiger** · October 4th, 2009

Aside from the obvious security implications if you cannot trust the source of the content (and by this I mean you can also trust the source itself to be secure from attack); some ideas:

In order of ‘robustness’

Can you assume that the content can be treated as well-formed XML? In that case the answer is fairly trivial because you can use XSLT to extract relevant data; adapting to the precise structure of the document on the fly.
Can you assume that you know where your data is (that is: can you assume a fixed structure)? In that case you can probably get away with loading the document into a DOMDocument object representation, then use that to extract data. Keep an eye on the necessary entity escape juggling!
Can you assume fairly basic search criteria? In that case you might even be able to get away with a regular expression or similar ad-hoc approach. This is by far the less robust option which should only be used for such basic extraction operations as ‘all <li> elements in the document which contain just plain text’. Anything much more complicated and your regex will cost you not only much more time than full-blown XSLT stylesheets, it will also be far less reliable, certainly far less maintainable, and likely fail you at the first upgrade ...

**esteeven** · October 4th, 2009

<?php echo "<li>"$listitem"</li>"; ?>
What I don't understand in the above is how to get the $listitem data.

**Reiger** · October 4th, 2009

Apart from the fact that there are 2 syntax errors in that statement...

... I was talking about an approach to extracting the data: not handing out ready-made code. Apart from security precautions; the rest is mostly implementation details anyone can look up on php.net anyways.

**esteeven** · October 4th, 2009

Originally Posted by Reiger

[*]Can you assume that you know where your data is (that is: can you assume a fixed structure)? In that case you can probably get away with loading the document into a DOMDocument object representation, then use that to extract data. Keep an eye on the necessary entity escape juggling![/list]

I think I can assume a fixed structure and I am just about able to follow the "loading into a DOMDocument" but I can only see this as a way of identifying the data location itself.

My limited knowledge stops me seeing how I can use php to actually extract/get to that data. I take your point about searching php.net and I have been doing this : am I on the right track with file_get_contents ?

edit: nope. I hadn't understood the DOMDocument business but I do now. PHP can load the entire page as a DOMDocument and then I can extract / get to elements that I want to display because I have something I can extract from. Am I doing better??