PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

760 Chapter 31 Building Web Forums
$this->m_title." - ".$this->m_poster." - ".
reformat_date($this->m_posted)."";
You then change the color for the next row:
// increment row counter to alternate colors
$row++;
After that, you add some code that will be executed by all treenodes, including the root
one, as follows:
// call display on each of this node's children
// note a node will only have children in its list if expanded
$num_children = sizeof($this->m_childlist);
for($i = 0; $im_childlist[$i]->display($row, $sublist);
}
return $row;
Again, this is a recursive function call, which calls on each of this node’s children to display
themselves.You pass them the current row color and get them to pass it back when
they are finished with it so that you can keep track of the alternating color.
That’s it for this class.The code is fairly complex.You might like to experiment with
running the application and then come back to look at it again when you are comfortable
with what it does.
Viewing Individual Articles
The display_tree() call gives you links to a set of articles. If you click one of these
articles, you will go to the view_post.php script, with a parameter of the postid of the
article to be viewed. Sample output from this script is shown in Figure 31.7.
The view_post.php script, shown in Listing 31.6, shows the message body, as well as
the replies to this message.The replies are again displayed as a tree but completely
expanded this time, and without any plus or minus buttons.This is the effect of the
$sublist switch coming into action.
Listing 31.6
view_post.php—Displays a Single Message Body