Advanced Search.. really that advanced!?

I, too, searched for forums for the answer and found none, so I hacked (and I used this term heavily) a way to do this. I thought I'd share, with lots of disclaimers that I am not a PHP pro and have no idea how elegant this solution is (or more likely, not). But, it works.

You need two parts. Firstly, you have to create an anchor at the actual advanced search area on the search page. Here's how I did it. Open node.module and find this part:

<?php
// Advanced node search form
  elseif ($form_id == 'search_form' && arg(1) == 'node') {
    // Keyword boxes:
    $form['advanced'] = array(
      '#type' => 'fieldset',
      '#title' => t('Advanced search'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#attributes' => array('class' => 'search-advanced'),
    );
?>

You're going to replace this with a conditional statement to look at the incoming URL (we'll get to that in part 2) and to figure out if it should set an anchor or not. It is also going to tell it to display advanced search uncollapsed if the intent is to link directly to advanced search. Here's what you replace with:

<?php
// Advanced node search form
  elseif ($form_id == 'search_form' && arg(1) == 'node') {
      //CODE ADDED BY ME TO CREATE ADVANCED SEARCH LINK
	if($_GET['url'] =='advsearch'){
		// Keyword boxes:
   	      $form['advanced'] = array(
      	'#type' => 'fieldset',
      	'#title' => t('Advanced search<a name=advsearch></a>'),
      	'#collapsible' => TRUE,
     		'#collapsed' => FALSE,
     		'#attributes' => array('class' => 'search-advanced'),
    		);		
	}else{
    		// Keyword boxes:
    		$form['advanced'] = array(
    		'#type' => 'fieldset',
      	'#title' => t('Advanced search'),
      	'#collapsible' => TRUE,
      	'#collapsed' => TRUE,
      	'#attributes' => array('class' => 'search-advanced'),
    		);
	}	
?>

The only thing I could not figure out how to do is how to eliminate the second little black arrow that this will generate to collapse/uncollapse the advanced search area. It doesn't affect the functionality, so i decided to live with it...maybe somebody else can figure this one out? Ok, now part 2. Open template.php in your theme. We're going to add a function:

<?php
function phptemplate_search_block_form($form) {
  //need this first line to prevent breaking of existing CSS in my theme b/c form will not render with this 
 //div if this function is called
  $output = '<div class="container-inline">'.form_render($form['field_one']);
  $output .= form_render($form);
  $output .= "<br /><a href=\"index.php?q=search/node&url=advsearch\" title=\"Advanced Search\">advanced search</a></div>";
  return $output;
}
?>

This code renders the search form and adds the actual link underneath it. If your search block is called something else, replace "function phptemplate_search_block_form" with "function phptemplate_whatever_the_name_is." That's it. Hope this helps somebody.

Lebachai

(Using Drupal 6.x)
I found this was a case of not seeing the forest for the trees. In my attempts to find a complicated answer for this, I found this easy solution that works.

Copy the search-block-form.tpl.php (from module/search) to your theme directory.

The file is pretty basic with the following code:

<div class="container-inline">
  <?php print $search_form; ?>
</div>

So I added in a line of code to get the following (wrapping the new link for easy theming):

<div class="container-inline">
<div class="advanced-search-link">
<a href="/search/node/" alt="Advanced search" >Advanced search &gt;&gt;</a>
</div>
  <?php print $search_form; ?>
</div>

And now I have a link in the search block that links straight to the advanced search page.

I don't think it is posssible however to add an argument to this link to auto-expand the 'advanced search' field group.