Silverstripe group result by specific subject - group-by

Question

I have Theses(datamodel) and Subject(datamodel) and Author(datamodel) i want to display my results grouped by subject
e.g.
Subject1
-Theses1
-Theses2
Subject2
-Theses3
...
what i have so far is the following
<?php
class ThesisDissertations extends Page {
}
class ThesisDissertations_Controller extends Page_Controller {
public function getSubject() {
$subjectgroup = new PaginatedList(Subject::get());
return $subjectgroup;
}
public function ThesesDissertations() {
$pages = new PaginatedList(Theses::get()
->leftJoin("Author", "Theses.AuthorID = Author.ID")
->leftJoin("Subject", "Theses.SubjectID = Subject.ID")
->where("Theses.SubjectID = 'getSubject'")
->sort('SubjectTitle'), $this->getRequest());
$pages->setPageLength(15);
return $pages;
}
}
and for the template
<div class="container"><ul><% loop $getSubject %>
$SubjectTitle
<br>
<% loop $ThesesDissertations %>
<!-- Trigger the modal with a button -->
<li><strong>$Author.AuthorName</strong></li>
<!-- Modal -->
<div id="$ID" class="modal fade" role="dialog">
<div class="modal-dialog modal-lg">
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title"><strong>$TitleTH</strong></h4>
<em>$CallNo, $Author.AuthorName </em>
</div>
<div class="modal-body">
<p class="text-justify">$Summary<br>Subjects : <em>$Subject.SubjectTitle</em>
<hr>
<em><strong>Physical Description :</strong> <% if $PhysicalDesc="" %>No Description Available<% else %>$PhysicalDesc<% end_if %><br>
<strong>Degree Course :</strong> $DegreeCourse<br>
<strong>Year Published :</strong> $Year</em></p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-danger" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div><br><% end_loop %><% end_loop %></ul></div>
Subject DataObject
class Subject extends DataObject{
private static $db = array (
'SubjectTitle' => 'Varchar',
);
private static $has_many = array (
'Theses' => 'Theses',
);
public function canView($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canEdit($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canDelete($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canCreate($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
private static $summary_fields = array(
'SubjectTitle',
);
}
?>
Theses Dataobject
class Theses extends DataObject{
private static $db = array (
'CallNo' => 'Varchar',
'AuthorID' => 'Int',
'TitleTH' => 'Text',
'Year' => 'Int(4)',
'PhysicalDesc' => 'Text',
'Notes' => 'Text',
'Summary' => 'Text',
'SubjectID' => 'Int',
'DegreeCourse' => 'Varchar',
);
private static $has_one = array (
'Author' => 'Author',
'Subject' => 'Subject',
);
private static $field_labels = array(
'CallNo' => 'Call Number',
'TitleTH' => 'Title Headings',
'Author.AuthorName'=>'Author',
'DegreeCourse'=>'Degree Course',
'Year'=>'Year Published',
'Subject.SubjectTitle'=>'Subject',
);
private static $summary_fields = array (
'CallNo' => 'CallNo',
'TitleTH' => 'TitleTH',
'Author.AuthorName',
'DegreeCourse',
'Year'=>'Year',
'Subject.SubjectTitle',
);
public function getCMSfields() {
$fields = FieldList::create(TabSet::create('Root'));
$fields->addFieldsToTab('Root.Main', array(
TextField::create('CallNo'),
DropdownField::create('AuthorID','AuthorName')->setEmptyString('-Select one-')->setSource(Author::get()->sort('AuthorName')->map('ID','AuthorName')),
TextField::create('TitleTH'),
NumericField::create('Year','Year')->setMaxLength(4),
TextField::create('PhysicalDesc'),
TextField::create('Notes'),
TextAreaField::create('Summary'),
DropdownField::create('DegreeCourse','DegreeCourse',array('BLIS' => 'BLIS','BLS' => 'BLS','MLIS' => 'MLIS','MLS' => 'MLS')),
DropdownField::create('SubjectID','SubjectTitle')->setEmptyString('-Select one-')->setSource(Subject::get()->sort('SubjectTitle')->map('ID','SubjectTitle')),
));
return $fields;
}
}
?>
Author dataobject[if you ever wanted]
class Author extends DataObject{
private static $db = array (
'AuthorName' => 'Varchar',
);
private static $has_many = array (
'Theses' => 'Theses',
);
public function canView($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canEdit($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canDelete($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
public function canCreate($member = null) {
return Permission::check('CMS_ACCESS_MyAdmin', 'any', $member);
}
private static $summary_fields = array(
'AuthorName',
); }?>

Answer 1

I'm not really sure what you've got exactly. In your datamodels, I take it that every thesis has a subject, and every subject can have multiple theses, and that these relations are defined in your models. Then you can supply your template with a list of subjects. You don't have to use a controller function for that. So just add "Subjects" => Subject::get() to the array that you pass to the template, and you can do the following: (shortened and untested, but you'll get the drift):
<% loop $Subjects %>
$SubjectTitle
<% loop $Theses %>
$CallNo, $Author.AuthorName
<% endloop %>
<% endloop %>
When you want to have Subjects available to the template, you can do the following.
In the page controller (in your case ThesisDissertations_Controller), add the following function:
public function index() {
return array("Subjects" => Subject::get());
}
You can pass all kinds of information to the template this way.