Replacing every third ....

patsfans

I'm trying to write a script to replace every third on our article display pages, to have a floating block on one side that appears after the third paragraph. Does anyone know a quick and easy way to achieve this?

Thanks in advance for your assistance!

patsfans

Actually I'm only looking to have it skip the first two, and then replace the third so that I can add it back along with the other table. Hopefully that makes this a little more clear.

johanafm

Well, what you actually want to do is unclear to me, but getting the third paragraph is very easy.

$d = new DOMDocument();
# Needs a complete html document: doctype + html, heady and body tags
# Otherwise it will fill your error log with warnings.
# Also requires a meta content-type tag if using other encoding than iso-8859-1
$d->loadHTML($html_string);

$ps = $d->getElementsByTagName('p');

# just do stuff with 3rd paragraph
$third_p = $ps->item(2);

# loop over all
foreach ($ps as $p) {

}

# or
for ($i = 0; $i < $ps->length; ++$i) {

}

patsfans

Here, hopefully this explains it better:

Basically I have a php page that displays my articles, and just need
to do an ereg_replace that replaces the third instance of a tag
with the tag plus a table so I can insert a table column that's
aligned left, with the remaining story wrapping around it.

The full body of the story is in a variable $body, that when echoed
outputs the article.

Example: (If I was replacing all of them)

$output =
ereg_replace("<p>","<p><table width=180 cellpadding=0 cellspacing=10
border=1 align=left><tr><td>Cell contents</td></tr></table>", $body);

I just can't figure out how to replace the third instance of that 
tag.

Example:

First paragraph with a bunch of words.
<p>
Second paragraph with a bunch of words.
<p>
Third paragraph with a bunch of words.
<p>
Fourth paragraph with a bunch of words along with the rest of the article.

To be replaced with:

First paragraph with a bunch of words.
<p>
Second paragraph with a bunch of words.
<p>
Third paragraph with a bunch of words.
<p>
<table width=180 cellpadding=0 cellspacing=10 border=1
align=left><tr><td>Cell contents</td></tr></table>
Fourth paragraph with a bunch of words along with the rest of the article.

Make sense? Obviously there are more tags in between paragraphs after this point depending on the length of the article, but I'm just looking to do a single replacement on the third instance of it.

Thanks in advance for your assistance!

Ian

johanafm

patsfans;10965013 wrote:
and just need to do an ereg_replace

You should never use ereg_anything, since those functions are deprecated. Moreover, you should preferably not use preg_anything either, since it's a lot easier to manipulate this through DOM.

patsfans;10965013 wrote:
that replaces the third instance of a tag
with the tag plus a table

Since the code I posted above gives you the third paragraph, all you have to do is insert your left floating table into the document before the third paragraph. For example by using DOMDocument::createElement to create a table, then set it to float left and finally insert it into the document using DOMDocument::insertBefore with a second argument of $third_paragraph.