In my php code, I have
<?php
$test = json_encode($array);//$array is a valid multidimensional array
?>
I am passing this variable to a javascript function and I am trying to set this variable to javascript.
<script>
var test = "<?php echo $test;?>";
</script>
(To clarify I am using codeigniter framework and for simplicity I did not use how I am sending the variable to the page)
But when I execute the above code, I am getting
Uncaught SyntaxError: Unexpected identifier
I have checked all my syntax.
Thank you in advance.
Don't put the decoded json array inside double quotes in the javascript. Change to this.
var test = <?php echo $test;?>;
It's not required to wrap the output of json_encode in quotes, otherwise it will be interpreted as a string. At which point you'll need to decode it within JavaScript.
Related
$_SESSION['consequnce1']=[1,2,3]
$consequenceStr1=implode( ',', $_SESSION['consequence1']); //for storage to databases
$_SESSION['consequence1']=explode(',', $consequence1);
//$_SESSION['consequence1'] now is like["1","2","3"].
in html, I want get the array[1,2,3].
var sess = JSON.parse("<?php echo json_encode($_SESSION['consequence1']); ?>");
var num =sess[0];
but this two line code does not work, what's the problem?
thanks
Answer: do not know the reason in fact. But just change
var sess = <?php echo json_encode($_SESSION['consequence1']); ?>;
then it works.
Thanks for others' reply
That is, because json_encode provides value that can be used directly in JavaScript. It wraps strings in double quotes and takes care of other types to be valid as well. JSON.parse takes string as an argument, which is not necessary.
In your example, you had messed double quotes, like this:
JSON.parse("["1","2","3"]")
I'm trying to pass a PHP variable to Javascript like this..
var url = <?php echo $urlArray[0]; ?>;
The contents of $urlArray[0] is a string from a json decoded array
"baby"
When I run the code I get the error..
Uncaught ReferenceError: baby is not defined
var url = "<?php echo $urlArray[0]; ?>";
you forgot the quotes.
If you need to export more complicated data structure, you may need json_encode. This might be helpful if exporting arrays and/or objects.
json_encode is your friend - use to wrap anything you're trying to pass to javascript.
http://php.net/manual/en/function.json-encode.php
var url = <?php echo json_encode($urlArray[0]); ?>;
I have a form with fields and a text-area that allows any characters to be entered. I can't just submit the form, because the form is being recycled many times over, so the form values are being stored in associative arrays:
<form name='Theform'>
<input type="text" id="VISITOR_DETAILS_NAME" value="Joe">
<input type="text" id="VISITOR_DETAILS_SIZE" value="Large">
<textarea id='VISITOR_DETAILS_INFO'>
User can enter anything here including double " and single ' quotes
</textarea>
<input type="hidden" name="package" id="package" value="" />
</form>
The text-area value are stored in a JavaScript array along with the other form values:
myArray[0]['VISITOR_DETAILS_NAME'] = document.getElementById('VISITOR_DETAILS_NAME').value;
myArray[0]['VISITOR_DETAILS_SIZE'] = document.getElementById('VISITOR_DETAILS_SIZE').value;
myArray[0]['VISITOR_DETAILS_INFO'] = document.getElementById('VISITOR_DETAILS_INFO').value;
I end up with an array something like this:
{
VISITOR_DETAILS_NAME : "Joe",
VISITOR_DETAILS_SIZE : "Large",
VISITOR_DETAILS_INFO : "User can enter anything here including double " and single ' quotes"
};
I then pass this JavaScript array to the hidden form field using JSON.stringify and then POST this to PHP:
document.getElementById('package').value = JSON.stringify(myArray[0]);
Theform.submit();
(For now I'm just posting to an iframe to test that the JSON is passing the JavaScript arrays properly through POST).
When I get it on the PHP side - it seems good to go. It looks like the JSON.stringify has added the backslash to the double quote (\" ) - and now I want to store the values in MySQL. But I want to first test that I can send/reconstruct the JSON back to the javascript as an array - so I try this:
parent.myArray[0] = JSON.parse('<?php echo $_POST['package']; ?>');
I get an ERROR: SyntaxError: Expected token ')' OR SyntaxError: missing ) after argument list
This is strange to me - because when I try it without POSTING - It seems to work fine like this:
document.getElementById('package').value = JSON.stringify(myArray[0]);
now if I try to just pass back the stringified value back to the array
myArray[0] = JSON.parse(document.getElementById('package').value);
- it seems to work fine - no errors
QUESTIONS:
Why am I getting this error when trying to reconstruct the ARRAY from the
POSTED JSON.stringify() value?
Do I save this JSON.stringify() value in MySQL as is?
Or do I PHP json_decode() it first?
I want to grab the form data - handle it properly - store it in MySQL and then read it back into the form when I need it.
Thanks All :)
parent.myArray[0] = JSON.parse('<?php echo $_POST['package']; ?>');
Here you are are trying to convert a JSON text into an HTML representation of a JavaScript string representation of a JSON text, but you aren't doing anything to escape it for either.
If you have any ' characters in the JSON data, then they will terminate the JavaScript string.
If you have any " characters in the JSON data, then they will be represented as \", but \" is a JavaScript string representation of ". Since you don't do anything to escape the text you put in the JS string, the slash character will be consumed by the JavaScript parser and will be gone before it reached the JSON parser.
If you want to convert data for placing in a JavaScript string then you need to escape it.
However, JSON is a subset (almost) of JavaScript. So the process of converting a JSON text to a JavaScript string so it can be parsed into a JavaScript object is over-complicated. You can skip that can just go straight to:
<script>
var foo = <?php echo $json; ?>
</script>
However, since you are taking in the JSON from the client, echoing out directly will expose you to XSS attacks. In order to deal with this you should filter the data on the server.
This will:
Fail to parse any invalid JSON and so not output bad JSON (but it might output nothing, giving you a JSON syntax error, you should apply tests to see if the parse was successful and output a sensible default case if it fails).
Convert any </script> in the data to <\/script> making it safe to place in a script element (because that is how PHP's json_encode works
Such:
<!-- I don't do PHP, this is untested -->
<script>
var foo = <?php
$unsafe_json = $_POST['package'];
$data_structure = json_parse($unsafe_json);
$safe_json = json_encode($data_structure);
echo $safe_json;
?>;
</script>
Do I save this JSON.stringify() value in MySQL as is? Or do I PHP json_decode() it first?
That depends on what you intend to do with the data. In general when putting things into a database it is a good idea to extra the data from the data format and normalize it. That way you can run queries over it.
If you are only going to store the data and then retrieve it, you might be able to get away with not doing that and storing strings of JSON in the database. That loses you a lot of flexibility though and might bite you in the future.
i have this in JAVASCRIPT , a.php -
function gettemplate(realnam) {
alert(realnam)
}
i want to pass all the a[] array in func_a.php to the first file a.php.. to use the array there in javascript .
how i do that?
thanks a lot
EDIT--
ITS WORKS ! , if anyone need --
$a= json_encode($a);
echo "<SCRIPT LANGUAGE='javascript'> gettemplate('$a');</SCRIPT>\n";
:)
you can return (echo) in the func_a.php an json string http://de.php.net/manual/en/function.json-encode.php and parse it in javascript
echo json_encode($a);
You will need to serialize and parse the Array, as XMLHttpRequests only can contain XML or raw text. The format of choice is JSON, which is broadly supported, including PHP and JavaScript.
Serverside you will use json_encode. Don't forget to serve the JSON with a valid MIME type. You also should encode your error messages to be valid JSON.
Clientside, i.e. in the callback function, you will use JSON.parse on the xmlhttp.responseText.
You also will find lots of information about this on the web, you only need to search.
Read about JSON particulary json_encode. func_a.php must return something like this:
header('Content-type: application/json');
echo json_encode($a);
To get object in javascript use this:
var myResponseObject = JSON.parse(xmlhttp.responseText);
Here's my problem. I have data being returned using JSON, AJAX from my php script to my page. The data is being stored in a variable data
Using the variable data, I'm trying to construct a div using javascript. However, if the data contains a single quote, it break my js code and the page script doesn't work.
example code with data being the variable containing data "The boy's bicycle":
var newrootcomment = $("<div id='container'>" + data + "</div>");
newrootcomment.prependTo($('#wholecontainer')).hide().fadeIn(300).slideDown(1000);
How do I solve this problem?
Are you using the json_encode function available in PHP? Are are you treating the response as JSON? jQuery.parseJSON(<json-string>).
From there you interact with it simple as an object.
var resp = {};
If you don't have jQuery, most browsers support JSON.parseJSON().
Also, make sure you use double quotes for attributes.
<div id="foo"></div>
This is normally how I use json_encode:
$resp = array(
"foo"=>"foo_value",
"bar"=>"bar_value",
"foo_bar"=>array("one","two",3),
"message"=>"AWesome"
)
return json_encode($resp)
Take a look at json_encode for PHP - it'll return a quoted string with JSON-safe characters - it'll escape entities like \n, \, ". etc
Edit
Note that a single quote in JSON is not required to be escaped since it surrounded by double quotes.
From what you said in a comment to #jbcurtin's answer, about your PHP code being echo json_encode('{ "author": "'.$author.'"}'); I'd say that that is one problem. You don't need to encode the entire string, only the author variable. That line should be echo '{"author": '. json_encode($author) . '}'; instead.