Passing JSON object to PHP with jQuery AJAX - php

Question

I have 3 different JSON objects I want to concatenate and send over to a PHP file with jQuery AJAX. I can retrieve the JSON object in the PHP file, but cannot figure out how to loop through the results.
Here's what I have so far:
//my 3 JSON objects:
var json_obj_1{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
var json_obj_2{
"test4_key":"test4_val"
}
var json_obj_3{
"json_arr":[
{
"test1":"test2",
"test3":"test4"
}
]
}
//concat these to send over to the PHP file:
var my_json_obj = json_obj_1.concat(json_obj_2);
//I found if I didn't stringify obj_3 they didn't concatenate for some reason
my_json_obj = my_json_obj.concat(JSON.stringify(json_obj_3));
//my_json_obj now looks like this:
{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
{
test4_key: test4_val
}
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}
Based on this question: Sending JSON to PHP using ajax, I don't stringify the final JSON object.
Here's the AJAX call to the PHP file:
$.ajax({
url: 'my_php_file.php',
data: {my_json_data: my_json_obj},
type: 'POST',
async: false,
dataType: 'json',
cache:false,
success:function(data, textStatus, jqXHR){
console.log('AJAX SUCCESS');
},
complete : function(data, textStatus, jqXHR){
console.log('AJAX COMPLETE');
}
});
This is what it looks like when retrieved in my PHP file:
echo $_POST['my_json_data'];
//outputs:
{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
{
test4_key: test4_val
}
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}
Here's where I run in to problems. I want to be able to loop through this in a foreach. From what I have read (php: loop through json array) I have to decode the JSON object. However when I do this and loop through the results I get: " PHP Warning: Invalid argument supplied for foreach() ".
Even if I stringify the JSON object before sending it over to the PHP file I get the same problem. I have been banging my head against a brick wall for hours with this. Any help will be massively appreciated.
Thanks in advance.
Solved:
I was going wrong when concatenating my JSON objects following this question: Merge two json/javascript arrays in to one array. Instead I just put them together like so:
my_json_obj = '['+json_obj_1+','+json_obj_2+', '+JSON.stringify(json_obj_3)+']';
I then use json_decode in my PHP file which works a treat. http://json.parser.online.fr/ was invaluable in debugging my dodgy JSON. A great tool for JSON beginners.

Answer 1

You should be stringifying the whole object, try the following:
var my_json_obj = json_obj_1;
$.each(json_obj_2, function(key,value){
my_json_obj[key]=value;
});
$.each(json_obj_3, function(key,value){
my_json_obj[key]=value;
});
Ajax request:
data: {my_json_data: JSON.stringify(my_json_obj)},
PHP:
print_r(json_decode($_POST['my_json_data']));

Answer 2

As you say you need to decode the JSON, but your JSON is not well formed so I think the decode function is failing which causes the foreach error. There needs to be a , between objects, there's missing quotes around test4_val and it needs to be inside a singular object/array
You can check your JSON is wellformed at:-
http://json.parser.online.fr/
I think you want it to look more like:-
[{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
},
{
"test4_key": "test4_val"
},
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}]