CODEWITHSUNDEEP
phpjavascriptajaxarraysjson
Howdy_McGee
Howdy_McGee

Reputation: 10635

Loop through JSON Array

I have a JSON array that I'm passing to PHP. Eventually I'll be passing and receiving alot more from my PHP file but for the moment this is it. Right now it's recieving 1 array and sending back that same array, no problem. I can loop through the data in Javascript but how do I loop through the array I pass to my PHP file? I get errors with foreach and a for loop didn't seem to help any. Suggestions?

Javascript

var fullName = ["John Doe", "Jane Doe"];

$(window).load(function(){
    getList();
});

function getList(){
    $.getJSON(
        "names.php",
        {names : JSON.stringify(fullName)},
        function(data) 
        {
            for(var i = 0; i < data.test.length; i++)
            {
                window.alert(data.test[i]);
            }
        }
      );
}

PHP

<?php
    $names=json_decode($_REQUEST['names']);

foreach($names as $name)
{
    echo $name;
}

    $data['test'] = $names;
    echo json_encode($data);

The foreach errors out on the foreach line telling me "Warning: Invalid argument supplied for foreach()"

Upvotes: 3

Views: 1704

Answers (6)

Martin Zeitler
Martin Zeitler

Reputation: 76619

/* client-side */
$.ajax({

   /* the request's method: */
   type: 'GET',

   /* the request's location: */
   url:'/names.php',

   /* the request's fields: */
   data: JSON.stringify({names: fullName}),

   /* the request's content-type : */
   contentType: 'application/json; charset=utf-8',

   /* the response's content-type: */
   dataType:'json',

   /* the callback function */ 
   success: function(json){

     if(json.length > 0){
         $.each(json, function(i, v){

            console.info(v);

         });
      }
      else {
         alert('wtf?!');
      }
});

/* server-side */
$req=array_merge($_GET, $_POST);

// die(print_r($req));

$names=json_decode($req['names']);
header('content-type: application/json; charset=utf8;');
echo json_encode($names);

Alternatively one could set the request-method for the request, I'm just a little lazy and with that array_merge() it just doesn't matter if the request was a POST or GET (well, function $.ajax defaults to GET). Best practice is to use FireBug and checkout it's net-panel, especially the XHR tab. Probably the question should have been: "How to use a XHR debugger?" because there's nothing tricky about this at all.

It seems that the jQuery API has been slightly updated (see the Deprecation Notice):

http://api.jquery.com/jQuery.ajax/

https://getfirebug.com

Upvotes: 0

James C
James C

Reputation: 14149

json_decode() doesn't return an array. To get it to do so you'd need to do json_decode($_REQUEST['names'], true)

http://php.net/manual/en/function.json-decode.php

Upvotes: 1

Shridhar
Shridhar

Reputation: 166

Try this, In your javascript function replace below line with 

 {names : JSON.stringify(fullName)},

with

"{names :"+ JSON.stringify(fullName) +"}",

debug test

var fullName = ['John Doe', 'Jane Doe'];
console.log({names : JSON.stringify(fullName)});
// gives Object { names="["John Doe","Jane Doe"]"}

but with 

console.log("{names :"+ JSON.stringify(fullName) +"}");
// gives {names :["John Doe","Jane Doe"]}

// so i guess second is correct json string to pass

Upvotes: 0

apoq
apoq

Reputation: 1454

Try 

$names=json_decode($_POST['names']); // or $_GET

instead of

$names=json_decode($_REQUEST['names']);

Sometimes $_REQUEST can be empty because of php.ini conf. SEE request_order

Upvotes: 0

Deathspike
Deathspike

Reputation: 8770

EDIT: jQuery is being insane again.

$.getJSON("names.php?names=" + encodeURIComponent(JSON.stringify(fullName)), function(data)
        {
                for(var i = 0; i < data.test.length; i++)
                {
                        window.alert(data.test[i]);
                }
        }
);

The problem was it was adding each item in the array as seperate value to URI.

Upvotes: 0

jeroen
jeroen

Reputation: 91734

There seems to be something strange going on when using:

{names : JSON.stringify(fullName)}

As you are sending key - value pairs using GET or POST, you probably need to encode the value correctly.

You could do that using:

{names : encodeURIComponent(JSON.stringify(fullName))}

Upvotes: 0

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