Develop Reference

How do you convert a JS array into a PHP array? [duplicate]

Let's say I have a javascript array with a bunch of elements (anywhere from 50-200).
I want to send that to PHP (prepared statement) using ajax. Currently, I .load a php file many times inside of a loop, but I want to convert that into an array and send the array once, loading the PHP file once instead of 50-200 times.
array[i] = variable;

You could use JSON.stringify(array) to encode your array in JavaScript, and then use $array=json_decode($_POST['jsondata']); in your PHP script to retrieve it.

AJAX requests are no different from GET and POST requests initiated through a <form> element. Which means you can use $_GET and $_POST to retrieve the data.
When you're making an AJAX request (jQuery example):
// JavaScript file
elements = [1, 2, 9, 15].join(',')
$.post('/test.php', {elements: elements})
It's (almost) equivalent to posting this form:
<form action="/test.php" method="post">
<input type="text" name="elements" value="1,2,9,15">
</form>
In both cases, on the server side you can read the data from the $_POST variable:
// test.php file
$elements = $_POST['elements'];
$elements = explode(',', $elements);
For the sake of simplicity I'm joining the elements with comma here. JSON serialization is a more universal solution, though.

Here's a function to convert js array or object into a php-compatible array to be sent as http get request parameter:
function obj2url(prefix, obj) {
var args=new Array();
if(typeof(obj) == 'object'){
for(var i in obj)
args[args.length]=any2url(prefix+'['+encodeURIComponent(i)+']', obj[i]);
}
else
args[args.length]=prefix+'='+encodeURIComponent(obj);
return args.join('&');
}
prefix is a parameter name.
EDIT:
var a = {
one: two,
three: four
};
alert('/script.php?'+obj2url('a', a));
Will produce
/script.php?a[one]=two&a[three]=four
which will allow you to use $_GET['a'] as an array in script.php. You will need to figure your way into your favorite ajax engine on supplying the url to call script.php from js.

So use the client-side loop to build a two-dimensional array of your arrays, and send the entire thing to PHP in one request.
Server-side, you'll need to have another loop which does its regular insert/update for each sub-array.

You can transfer array from javascript to PHP...
Javascript... ArraySender.html
<script language="javascript">
//its your javascript, your array can be multidimensional or associative
plArray = new Array();
plArray[1] = new Array(); plArray[1][0]='Test 1 Data'; plArray[1][1]= 'Test 1'; plArray[1][2]= new Array();
plArray[1][2][0]='Test 1 Data Dets'; plArray[1][2][1]='Test 1 Data Info';
plArray[2] = new Array(); plArray[2][0]='Test 2 Data'; plArray[2][1]= 'Test 2';
plArray[3] = new Array(); plArray[3][0]='Test 3 Data'; plArray[3][1]= 'Test 3';
plArray[4] = new Array(); plArray[4][0]='Test 4 Data'; plArray[4][1]= 'Test 4';
plArray[5] = new Array(); plArray[5]["Data"]='Test 5 Data'; plArray[5]["1sss"]= 'Test 5';
function convertJsArr2Php(JsArr){
var Php = '';
if (Array.isArray(JsArr)){
Php += 'array(';
for (var i in JsArr){
Php += '\'' + i + '\' => ' + convertJsArr2Php(JsArr[i]);
if (JsArr[i] != JsArr[Object.keys(JsArr)[Object.keys(JsArr).length-1]]){
Php += ', ';
}
}
Php += ')';
return Php;
}
else{
return '\'' + JsArr + '\'';
}
}
function ajaxPost(str, plArrayC){
var xmlhttp;
if (window.XMLHttpRequest){xmlhttp = new XMLHttpRequest();}
else{xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");}
xmlhttp.open("POST",str,true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send('Array=' + plArrayC);
}
ajaxPost('ArrayReader.php',convertJsArr2Php(plArray));
</script>
and PHP Code... ArrayReader.php
<?php
eval('$plArray = ' . $_POST['Array'] . ';');
print_r($plArray);
?>

How to read a javascript object

I am using from Microsoft the
Live Connect Developer Center
It returns this type of variable for a contact but I don't know of a simple way to read it, would perform split on it but do not know how to read this object:
{"id":"contact.0d3d6bf0000000000000000000000000", "first_name":"William", "last_name":"Shakespeare", "name":"William Shakespeare", "gender":null, "is_friend":false, "is_favorite":false, "user_id":"2ae098749083cb3d", "email_hashes":["a790b818acfdef744a23bef534dfd9a4a53aa834250bdfe55f6874543129daa6"], "updated_time":"2012-10-04T19:23:34+0000"}
I'd need to access name and email_hashes with what's inside of it:
a790b818acfdef744a23bef534dfd9a4a53aa834250bdfe55f6874543129daa6 - without the brackets.
Just don't know how to read this kind of object.

JSON.parse() is specifically designed to take a string in JSON format and produce a JavaScript object, from which you can then access properties.

That looks like JSON. If you're using jQuery, you could do something like this:
var jsonData = $.parseJSON('{"id":"contact..."}');
alert('name: ' + jsonData.id);
See the docs for more usage examples: http://api.jquery.com/jQuery.parseJSON/

The response you're receiving is a key/value pair. You can access any value with the key
obj[key] // value
or
obj.key // value

if
var x = {"id":"contact.0d3d6bf0000000000000000000000000", "first_name":"William", "last_name":"Shakespeare", "name":"William Shakespeare", "gender":null, "is_friend":false, "is_favorite":false, "user_id":"2ae098749083cb3d", "email_hashes":["a790b818acfdef744a23bef534dfd9a4a53aa834250bdfe55f6874543129daa6"], "updated_time":"2012-10-04T19:23:34+0000"}
then
x.email_hashes
returns
["a790b818acfdef744a23bef534dfd9a4a53aa834250bdfe55f6874543129daa6"]
and
x.email_hashes[0]
returns
"a790b818acfdef744a23bef534dfd9a4a53aa834250bdfe55f6874543129daa6"

When you get your variable with the JSON, do this:
var stringData = {}, // Incoming data
data = JSON.parse(stringData);
Then, you can access the variables like this:
var id = data.id,
firstName = data.first_name;
To access array values, do this:
var emailHashes = data.email_hashes;
if (emailHashes.length > 0) {
var i = 0;
for (; i < emailHashes.length; i++) {
// perform some action on them.
}
}

Javascript Form: Only Changed Fields

I have a php-site with a form on which i output preselected values via php. On form submit I want to check which values have changed and just submit these via javascript.
These are the preselected values I passed over from php. It's important that I keep the associative array structure.
var pbData = jQuery.parseJSON("{
"GameMode":"DEATHMATCH",
"Current Map":"VEGAS JUNKYARD",
"Current Missions":["VEGAS JUNKYARD","VILLA","PRESIDIO","KILL HOUSE","MURDERTOWN","CQB TRAINING","STREETS","THREE KINGDOMS CASINO","IMPORT\/EXPORT;"],
"RoundDuration":"3 minutes"}");
I marked the error in the code.
<script>
function displayVars(){
var form = document.getElementById('settings');
var elems = form.elements;
var txt = "";
for (var index = 0; index < elems.length; index++){
var selIndex = elems[index].selectedIndex;
if (typeof selIndex !== "undefined"){
//the Index Name in the json-object and the name of the form-field are the same
var idxName = elems[index].name;
//HERE is the problem. I want to access the subobject via a variablename, so i can iterate through it, but that doesnt work.
console.log ("pbData default = "+pbData.idxName); //always undefined
if (elems[index].value !== pbData.idx_name){
//building a POST-Url
txt = txt + elems[index].name + "=" + elems[index].options[selIndex].value+"&";
}
}
}
console.log (txt);
return false;
}
</script>
I know that I could do this differently, also with jQuery. In my case as I have the preselected values as a php-variable in any case, i think it's easier like this.
I would really like to know how I can iterate through the subobjects via a variable that contains the object names.

This is due to how you'e trying to access the property of the (JSON) object. Consider
var o1 = {idxName: true},
o2 = {foo : 'bar'},
idxName = 'foo';
o1.idxName; // true
o2.idxName; // undefined
o2[idxName]; // 'bar'
You need to access the property via pbData[idxName].
Additionally, you're not escaping quotes in your JSON string, and line breaks need to be escaped as follows
var pbData = jQuery.parseJSON("{\
\"GameMode\":\"DEATHMATCH\",\
\"Current Map\":\"VEGAS JUNKYARD\",\
\"Current Missions\":[\"VEGAS JUNKYARD\",\"VILLA\",\"PRESIDIO\",\"KILL HOUSE\",\"MURDERTOWN\",\"CQB TRAINING\",\"STREETS\",\"THREE KINGDOMS CASINO\",\"IMPORT\/EXPORT;\"],\
\"RoundDuration\":\"3 minutes\"}");

In Javascript you could keep an object or array with initial values and only post those values that are changed.
But in fact, I would do something similar, but in PHP. You can keep the original values in the session and compare the posted values to those initial values to see what has changed. That way, you won't depend on Javascript. Not only may Javascript be disabled, but also, a fast user may theoretically post the form before the Javascript has run. To move this check to PHP eliminates that risk.

Issue with JSON stringify?

/* Helper function to clean up any current data we have stored */
function insertSerializedData(ids, type) {
// Get anything in the current field
current_data = $('#changes').val();
if (!current_data) {
var data = new Array();
data[type] = ids;
$('#changes').val(JSON.stringify(data));
} else {
var data = JSON.parse($('#changes').val());
data[type] = ids;
$('#changes').val(JSON.stringify(data));
}
console.log($('#changes').val());
}
I am using the following function to either add data to a current JSON object or create a new JSON object all together to be used in PHP later. Is the stringify() method only for FF? I am using google chrome and I am being given an empty object when using the conosole.log() function...
Also what happens if you try to store two values with the same key? I assume it will overwrite...so I should add a random math number at the end array in order to keep duplicates from showing up?
Thanks :)

These lines may cause problems:
var data = new Array();
data[type] = ids;
... because arrays in JavaScript are not quite like arrays in PHP. I suppose what you meant is better expressed by...
var data = {};
data[type] = ids;
Besides, current_data seems to be local to this function, therefore it also should be declared as local with var. Don't see any other problems... except that similar functionality is already implemented in jQuery .data() method.
UPDATE: here's jsFiddle to play with. ) From what I've tried looks like the array-object mismatch is what actually caused that Chrome behavior.

I reformatted it a bit, but and this seems to work. It will set the "value" attribute of the #changes element to a JSON string. I assume that the type argument is supposed to be the index of the array which you're trying to assign?
function insertSerializedData(ids, type) {
var changes = jQuery('#changes'), arr, val = changes.val();
if (!val) {
arr = [];
arr[type] = ids;
changes.val(JSON.stringify(arr));
} else {
arr = JSON.parse(val);
arr[type] = ids;
changes.val(JSON.stringify(arr));
}
console.log(changes);
}

Convert js Array() to JSon object for use with JQuery .ajax

in my app i need to send an javascript Array object to php script via ajax post. Something like this:
var saveData = Array();
saveData["a"] = 2;
saveData["c"] = 1;
alert(saveData);
$.ajax({
type: "POST",
url: "salvaPreventivo.php",
data:saveData,
async:true
});
Array's indexes are strings and not int, so for this reason something like saveData.join('&') doesn't work.
Ideas?
Thanks in advance

Don't make it an Array if it is not an Array, make it an object:
var saveData = {};
saveData.a = 2;
saveData.c = 1;
// equivalent to...
var saveData = {a: 2, c: 1}
// equivalent to....
var saveData = {};
saveData['a'] = 2;
saveData['c'] = 1;
Doing it the way you are doing it with Arrays is just taking advantage of Javascript's treatment of Arrays and not really the right way of doing it.

If the array is already defined, you can create a json object by looping through the elements of the array which you can then post to the server, but if you are creating the array as for the case above, just create a json object instead as sugested by Paolo Bergantino
var saveData = Array();
saveData["a"] = 2;
saveData["c"] = 1;
//creating a json object
var jObject={};
for(i in saveData)
{
jObject[i] = saveData[i];
}
//Stringify this object and send it to the server
jObject= YAHOO.lang.JSON.stringify(jObject);
$.ajax({
type:'post',
cache:false,
url:"salvaPreventivo.php",
data:{jObject: jObject}
});
// reading the data at the server
<?php
$data = json_decode($_POST['jObject'], true);
print_r($data);
?>
//for jObject= YAHOO.lang.JSON.stringify(jObject); to work,
//include the follwing files
//<!-- Dependencies -->
//<script src="http://yui.yahooapis.com/2.9.0/build/yahoo/yahoo-min.js"></script>
//<!-- Source file -->
//<script src="http://yui.yahooapis.com/2.9.0/build/json/json-min.js"></script>
Hope this helps

You can iterate the key/value pairs of the saveData object to build an array of the pairs, then use join("&") on the resulting array:
var a = [];
for (key in saveData) {
a.push(key+"="+saveData[key]);
}
var serialized = a.join("&") // a=2&c=1

There is actuly a difference between array object and JSON object. Instead of creating array object and converting it into a json object(with JSON.stringify(arr)) you can do this:
var sels = //Here is your array of SELECTs
var json = { };
for(var i = 0, l = sels.length; i < l; i++) {
json[sels[i].id] = sels[i].value;
}
There is no need of converting it into JSON because its already a json object.
To view the same use json.toSource();

When using the data on the server, your characters can reach with the addition of slashes eg
if string = {"hello"}
comes as string = {\ "hello \"}
to solve the following function can be used later to use json decode.
<?php
function stripslashes_deep($value)
{
$value = is_array($value) ?
array_map('stripslashes_deep', $value) :
stripslashes($value);
return $value;
}
$array = $_POST['jObject'];
$array = stripslashes_deep($array);
$data = json_decode($array, true);
print_r($data);
?>