Hi, I’m new to Silverstripe this week (so, v3…) so apologies if there is a better forum area for this. I’ve been searching and can’t find a solution. Should be simple for those with experience so I hope you can help…

I’ve set up a number of pages, classed CaseStudyPage, that are all children of one CaseStudiesHolder page.

Each CaseStudyPage could have any number of Skills associated with it so I’ve managed to set up a DataObject called Skill, which has a many_many relationship with CaseStudyPage. All good so far. Phew.

Now, in my CaseStudiesHolder page I want to show teasers for all of its children – easy. But then I want the front end user to be able to click on one of a few skill links to filter the list of CaseStudyPages to just the ones that have that skill.

I don’t think I need to be fancy and let them choose more than one skill so the link could be a simple ‘a’ tag with a GET variable passed to the same page. How would the page then filter the list of CaseStudyPages? Any tips on what I should/could be using here would be very welcome, thanks.

Any clues? Is it best to filter $children in the template with if/else? Should I make a public function and query the DB? How would I go about using the GET/POST vars for this?

I have spent so many hours deciphering the docs and other online material to get this far, even getting a module to work. Just need a few pointers from an experienced member to get going with this task in the right direction. Help a Wellingtonian out?

There are all kinds of more or less sophisticated ways to do this, but this would be sort of simple:

Create the links (CaseStudiesHolder.ss):

<% loop Children %>
	<a href="{$Top.Link}?skill=$URLSegment">$Title</a><br>
<% end loop %>

Return the requested skills (CaseStudiesHolder_Controller):

public function getSkillPages() {
	$vars = $this->request->requestVars();
		
	if (!empty($vars['skill'])) {
		$skill = $vars['skill'];
		return $this->Children()->filter(array('URLSegment' => $skill));
	}
	return $this->Children();
}

Show requested skills (CaseStudiesHolder.ss)

<% loop $SkillPages %>
	<h3>$Title</h3>
<% end_loop %>

Note: this is simplyfied, you'd need to add your validation/sanitizing

Thanks, that helps me understand how the public function can be used to narrow results but the filter itself might need to be quite complex – I am not sure how to write it because of the many_many relationship of skills.

CaseStudiesHolder lists CaseStudyPages, CaseStudyPages have one or more Skills associated with them. I need to filter the CaseStudyPages from the CaseStudiesHolder depending on the one skill supplied via GET or however, eg 'Tank driving'.

Do I need a left join or is there an easy to filter the pages: "show only child pages that have a skill named 'Tank driving' in their skill set.

// The pages that are listed:
class CaseStudyPage extends Page {
    private static $many_many = array(
        'Skills' => 'Skill'
    );
     public function getCMSFields() {
        $fields = parent::getCMSFields();
        $Skills = DataObject::get('Skill');
        $fields->addFieldToTab("Root.Main", new CheckboxsetField('Skills', 'Skills', $Skills));
        return $fields;
    }
}

// Skill is a DataObject:
class Skill extends DataObject {
    public static $db = array(
        'Name' => 'Varchar'
    );
    private static $belongs_many_many = array(
        'CaseStudyPages' => 'CaseStudyPage'
    );
}

// The holder that lists the pages - 
// filtered by one skill (filter by multiple might be ideal but one will do)
class CaseStudiesHolder extends Page {
    private static $allowed_children = array('CaseStudyPage');
}
class CaseStudiesHolder_Controller extends Page_Controller {
    public function getCaseStudyList() { 
       $vars = $this->request->requestVars(); 
       if (!empty($vars['skill'])) { 
          $skill = $vars['skill']; 
          // NEED WORKING FILTER HERE-----------------------//
          return $this->Children()->filter(array('Skills.Name' => $skill));
       } 
       return $this->Children(); 
    }
}

I could list this in a different forum if you think it isn't suited here - Would the Data Model forum be better?

Thanks for your help.

Think I have it:

$skill = $vars['skill']; 
$skillObj = Skill::get()->filter(array('Name' => $skill))->First();
return $skillObj->CaseStudyPages(); 

Thanks to this: http://stackoverflow.com/questions/12146586/silverstripe-3-leftjoin

Not even sure how this works yet, but it does so I'm celebrating.

Seems like the GET var doesn't need to be escaped either: http://doc.silverstripe.org/framework/en/topics/security