Form that sends you a download link

<form action="eformaction" method="post" accept-charset="utf-8">
	<p> <input type="hidden" name="property_pdf" value="property_pdf" id="some_name"></p>
	<p><input type="submit" value="Download File"></p>
</form>

<a href="downloadform.html?file_id=somefile">Some File</a>

<input type="hidden" name="file_id" value="[+file_id+]" />

[[eFormEventFunctions]]
[!eForm? &eFormOnBeforeParse=`onBeforeParseFunction` &eFormOnBeforeMailSent=`onBeforeMailSentFunction` ... ret of params ]]

<?php
function onBeforeParseFunction(&$fields,&$templates){
   global $modx;
   #If no file is selected redirect to another page (with download links?) 
   $pageId = 1; //change to id of whatever page you want to redirect to.
   if(!isset($_REQUEST['file_id'])){ 
      $modx->sendRedirect($modx->makeUrl($pageId));
      return false;
   }else{
      #store file_id in form so it propagates
      $templates['tpl'] = str_replace('[+file_id+]',$_REQUEST['file_id'],$templates['tpl']);
      return true; //process normally
   }
}

function onBeforeMailSentFunction(&$fields){
   #is called when form is submitted succesfully
   #file_id should now be in the fields array
   $file = 'files/'.$fields['file_id'].'.pdf';
   #check that file exists
   if(!file_exists($modx->config['rb_base_dir']).$file){
      $fields['validationmessage']='The file you requested does not or no longer exists!';
      return false;
   }else{
      #Get the url belonging to file_id and store in fields array
      # In your report template place a [+download_url+] place holder
      $url = $modx->config['rb_base_url'] . 'files/'.$fields['file_id'].'.pdf';
      $fields['download_url'] = $url;
      return true;
   }
}
?>

// This is what appears on the page template
             [[eFormEventFunctions]]
             [!eForm? &eFormOnBeforeParse=`onBeforeParseFunction` &eFormOnBeforeMailSent=`onBeforeMailSentFunction` &formid=`downloads_form` &tpl=`downloads_form`!]

// Downloads is a page
// press release is a PDF
<a href="/downloads?file_id=Press_release">Some File</a>

// Downloads form chunk

<form method="post" action="/[~[*id*]~]" id="form">

<input type="text" name="file_id" value="[+file_id+]" /> <!-- it should put the value of the file in here, but it doesn't display anything -->
<input type="hidden" name="formid" value="download_form" />  

</form>

[[testy]]  // force output the $REQUEST 
[[eFormEventFunctions]]  // do the functions
[[testy2]] // force output the contents of $templates, $fields, etc.
[!eForm? stuff... !]

<?php
print "<br />TEMPLATE DATA: " . $templates;
print_r($templates);
print '<br />';
print "<br />TEMPLATE DATA2: " . $template;
print_r($template);
print '<br />';
print "FIELDS: ".  $fields;
print_r($fields);
?>