cakephp - sorting by a second level association in paginate - php

Question

I am playing around with a quotes database relating to a ski trip I run. I am trying to list the quotes, but sort by the person who said the quote, and am struggling to get the paginate helper to let me do this.
I have four relevant tables.
quotes, trips, people and attendances. Attendances is essentially a join table for people and trips.
Relationships are as follows;
Attendance belongsTo Person hasMany Attendance
Attendance belongsTo Trip hasMany Attendance
Attendance hasMany Quote belongs to Attendance
In the QuotesController I use containable to retrieve the fields from Quote, along with the associated Attendance, and the fields from the Trip and Person associated with that Attendance.
function index() {
$this->Quote->recursive = 0;
$this->paginate['Quote'] = array(
'contain' => array('Attendance.Person', 'Attendance.Trip'));
$this->set('quotes', $this->paginate());
}
This seems to work fine, and in the view, I can echo out
foreach ($quotes as $quote) {
echo $quote['Attendance']['Person']['first_name'];
}
without any problem.
What I cannot get to work is accessing/using the same variable as a sort field in paginate
echo $this->Paginator->sort('Name', 'Attendance.Person.first_name');
or
echo $this->Paginator->sort('Location', 'Attendance.Trip.location');
Does not work. It appears to sort by something, but I'm not sure what.
The $quotes array I am passing looks like this;
Array
(
[0] => Array
(
[Quote] => Array
(
[id] => 1
[attendance_id] => 15
[quote_text] => Hello
)
[Attendance] => Array
(
[id] => 15
[person_id] => 2
[trip_id] => 7
[Person] => Array
(
[id] => 2
[first_name] => John
[last_name] => Smith
)
[Trip] => Array
(
[id] => 7
[location] => La Plagne
[year] => 2000
[modified] =>
)
)
)
I would be immensely grateful if someone could suggest how I might be able to sort by the the first_name of the Person associated with the Quote. I suspect my syntax is wrong, but I have not been able to find the answer. Is it not possible to sort by a second level association in this way?
I am pretty much brand new with cakephp so please be gentle.
Thanks very much in advance.

Answer 1

I've had the similar problem awhile back. Not with sort though. Try putting the associated table in another array.
echo $this->Paginator->sort('Name', 'Attendance.Person.first_name');
change to:
echo $this->Paginator->sort('Name', array('Attendance' => 'Person.first_name'));
Hope this helps

Answer 2

i'm also looking for help with this.
so far i've found that you can sort multi level associations in controller's pagination options after using the linkable plugin https://github.com/Terr/linkable.
but it breaks down when you try to sort form the paginator in the view. i'm using a controller for magazine clippings. each clipping belongs to an issue and each issue belongs to a publication.
$this->paginate = array(
"recursive"=>0,
"link"=>array("Issue"=>array("Publication")),
"order"=>array("Publication.name"=>"ASC",
"limit"=>10);
after debugging $this->Paginator->params->paging->Clipping in the view, you can see that the sort is described in two separate places, "defaults" and "options". the sort info needs to be present in both for it to work in the view.
here is after setting order in controller:
[Clipping] => Array
(
[page] => 1
[current] => 10
[count] => 6685
[prevPage] =>
[nextPage] => 1
[pageCount] => 669
[defaults] => Array
(
[limit] => 10
[step] => 1
[recursive] => 0
[link] => Array
(
[Issue] => Array
(
[0] => Publication
)
)
[order] => Array
(
[Publication.name] => ASC
)
[conditions] => Array
(
)
)
[options] => Array
(
[page] => 1
[limit] => 10
[recursive] => 0
[link] => Array
(
[Issue] => Array
(
[0] => Publication
)
)
[order] => Array
(
[Publication.name] => ASC
)
[conditions] => Array
(
)
)
)
and here is after using $this->Paginator->sort("Publication","Publication.name");.
notice the options array is empty.
[Clipping] => Array
(
[page] => 1
[current] => 10
[count] => 6685
[prevPage] =>
[nextPage] => 1
[pageCount] => 669
[defaults] => Array
(
[limit] => 10
[step] => 1
[recursive] => 0
[link] => Array
(
[Issue] => Array
(
[0] => Publication
)
)
[order] => Array
(
[Publication.name] => DESC
)
[conditions] => Array
(
)
)
[options] => Array
(
[page] => 1
[limit] => 10
[recursive] => 0
[link] => Array
(
[Issue] => Array
(
[0] => Publication
)
)
[order] => Array
(
)
[conditions] => Array
(
)
)
does one really need to modify the paginator class to make this work?
UPDATE:
i found out the problem:
in the core cake controller paginator merges default and options to create the find query.
but the options array is empty when using linkable to sort. because options is listed after default it overrides default and the empty array replaces the default array of options.
solution to this is extending the paginate function inside of app_controller.php and unsetting the options array order value if it is empty:
(line 1172 in cake/libs/controller/controller.php)
if(empty($options["order"])){
unset($options["order"]);
}
then the options will not be overwritten by thte blank array.
of course this should not be changed inside of controller.php, but put it in app_controller.php and move it to your app folder.

Answer 3

On CakePHP 3 this problem can be solved by adding 'sortWhitelist' params to $this->paginate on your controller.
$this->paginate = [
// ...
'sortWhitelist' => ['id', 'status', 'Attendance.Person.first_name']
];
And then in your view:
echo $this->Paginator->sort('Name', 'Attendance.Person.first_name');
This is noted in the docs:
This option is required when you want to sort on any associated data, or computed fields that may be part of your pagination query:
However that could be easily missed by tired eyes, so hope this helps someone out there!