在CakePHP中自定义JSON输出

Question

In CakePHP 2.4, what is the correct syntax to foreach through my data in order to customize the contents and structure of JSON output from my controller?

I currently have the following method, which creates a .json that directly mirrors Cake's internal array of all my posts:

public function points() {
$this->autoRender = false; // We don't render a view in this example
$this->Post->recursive = -1; //Don't return stuff we don't need

return json_encode($this->Post->find('all'));
}

This creates JSON that looks like this, with each post's data the child of its own Post object (prettified with carriage returns so you can read it):

[{"Post":{"id":"1",
          "user_id":"1",
          "organism_id":"0",
          "title":"Title Text",
          "lat":"44.54401744186992",
          "lng":"-68.26070404052734",
          "body":"Body Text",
          "created":"2014-01-19 07:13:29",
          "modified":"2014-01-19 07:13:29"}
 },
 {"Post":{"id":"2",
          "user_id":"1",
          "organism_id":"0",
          "title":"Title Text",
          "lat":"44.54401744186992",
          "lng":"-68.26070404052734",
          "body":"Body Text",
          "created":"2014-01-19 07:13:29",
          "modified":"2014-01-19 07:13:29"}
 }]

This is a problem, because (A) For performance reasons, I might not want to dump all the data for each post into the JSON, and (B) for output to Google Maps, I need to output each post's data as child objects of one Posts object, like so:

{"Posts":[
    {"id":"1",
    "user_id":"1",
    "organism_id":"0",
    "title":"Title Text",
    "lat":"44.54401744186992",
    "lng":"-68.26070404052734",
    "body":"Body Text",
    "created":"2014-01-19 07:13:29",
    "modified":"2014-01-19 07:13:29"
},
    {"id":"2",
    "user_id":"1",
    "organism_id":"0",
    "title":"Title Text",
    "lat":"44.54401744186992",
    "lng":"-68.26070404052734",
    "body":"Body Text",
    "created":"2014-01-19 07:13:29",
    "modified":"2014-01-19 07:13:29"}]}

I know I somehow need to foreach through the data and build an array. How does this work? foreach ($posts as $post): doesn't work inside the controller.

Answer 1

I found the solution!

In the controller:

public function points() {
    $this->request->onlyAllow('ajax'); //Don't respond to non-AJAX requests
    $this->Post->recursive = -1; //don't return info from other controllers
    $this->set('posts', $this->Post->find('all'));
}

In /view/posts/json/points.ctp:

foreach ($posts as $post) {
$markers[] = array(
    'id' => $post['Post']['id'],
    'lat' => $post['Post']['lat'],
    'lng' => $post['Post']['lng']
    ); //make an array of the contents of each post I want to include

}

$data = array(
'Posts' => $markers); //Make everything the child of a 'Posts' object

 echo json_encode($data); //Turn it into JSON!