connection between android app and cakephp - php

Question

Hi I'm making a web service in cakephp for an android app. I am getting the request and the respose is being send but the response is not visible on the client's end. My code is as shown below. Can there be some other method to send the response.
public function AndroidApp() {
if (isset($_POST["myHttpData"])) {
$coupon = trim($_POST["myHttpData"]);
$couponId = $this->Code->find('all', array(
'conditions' => array(
'Code.coupon_code' => $coupon,
'Code.status' => 'Used'
),
'fields' => array('Code.id')));
$studentAssessmentId = $this->StudentAssessment->find('all', array(
'conditions' => array(
'StudentAssessment.code_id' => $couponId[0]['Code']['id'],
'StudentAssessment.status' => 'Complete'
),
'fields' => array('StudentAssessment.id')));
$scores = $this->AssessmentScore->find('all', array(
'conditions' => array(
'AssessmentScore.student_assessment_id' => $studentAssessmentId[0]['StudentAssessment']['id']
),
'fields' => array('AssessmentScore.score')));
$json = array();
$assessment_data = array();
//debug($scores);
$i = 0;
foreach ($scores as $score) {
$assessment_data[$i] = array("score" => $score['AssessmentScore']['score']);
$i+=1;
}
header('Content-type: application/json');
$json['success'] = $assessment_data;
$android = json_encode($json);
} else {
$json['error'] = "Sorry, no score is available for this coupon code!";
$android = json_encode($json);
}
echo $android;

Answer 1

code smell, non-cakephp standards
First of all, as mentioned in comments by others, you're not using the CakePHP request/response objects. Because of this, you're overly complicating things. See the documentation here;
http://book.cakephp.org/2.0/en/controllers/request-response.html
http://book.cakephp.org/2.0/en/controllers/request-response.html#dealing-with-content-types
And
http://book.cakephp.org/2.0/en/views/json-and-xml-views.html
The $scores loop to reformat the query results is probably redundant if you replace the find('all') with find('list'), using 'score' as display field. See the documentation here http://book.cakephp.org/2.0/en/models/retrieving-your-data.html#find-list
bugs
There also seems to be some bugs in your code;
the content-type header is only sent if $_POST["myHttpData"] is present.
you're only checking if $_POST["myHttpData"] is present, not if it actually contains any data (empty)
you're not checking if the various queries return a result. This will cause errors in your code if a query did not return anything! For example, you assume that $couponId[0]['Code']['id'] is present (but it won't be if the coupon-code was not found)
possible answer
Apart from these issues, the most probable cause for your problem is that you did not disable 'autoRender'. Therefore CakePHP will also render the view after you've output your JSON, causing a malformed JSON response.
public function AndroidApp() {
$this->autoRender = false;
// rest of your code here
}