firefox complaining about valid json... invisible invalid character? - php

I'm writing a php script that needs to load a 2D array into a js variable as json. First i make the array then use json_encode to turn it into a string. Then I run a small bit of js to get it accessable on the client side. Like so:
$sBaseData = Filters::$sFilterBaseTypeData;
$sBaseData = str_replace('\r',' ',$sBaseData);
$sBaseData = str_replace('\n',' ',$sBaseData);
$sBaseData = str_replace('\t',' ',$sBaseData);
echo <<<HTML
<script type="text/javascript">
var validation_data = JSON.parse('$sBaseData');
</script>
HTML;
Firefox complains about an unexpected character here:
var validation_data = JSON.parse('{"enumeration":{"js":"","msg":""},"date":{"js":" var parts = widget.value.split('-'); var d = new Date(parts[0],parts[1],parts[2]); PASS = (d.getDay()>=1); ","msg":"Invalid date. Please Enter a date in the format: YYYY-MM-DD"},"text":{"js":"","msg":"what did you do?"},"integer":{"js":"if (isNaN(widget.value)) { PASS = false; } else { intVal = parseInt(widget.value); PASS = (widget.value == intVal); } ","msg":"Please enter an integer value"},"decimal":{"js":"PASS = isNaN(widget.value); ","msg":"Please enter a number"},"group":{"js":"","msg":""},"dealer":{"js":"","msg":""}}')
I tried using http://jsonlint.com/ to find out which character was at fault but it says it's all valid and wonderful. I replaced some characters that were causing issues, is there anything else I should be replacing?

The problem is you have ' in your string while you are using ' to quote the string.
If your json string is valid, you don't need to parse it even. The below will work.
echo <<<HTML
<script type="text/javascript">
var validation_data = {$sBaseData};
</script>
HTML;

Uh...
var parts = widget.value.split('-');
Putting that in a string that uses single quotes will break it. Use a JSON encoder to output your JavaScript literal.

Your JSON is valid but in your js code the simple quote closes the parse function's argument.
Try like this:
"date":{"js":" var parts = widget.value.split(\'-\');

Related

parseJson is running into an unexpected error (Unexpected identifier)

This is all in the same script. I know the difference between ajax and serverside code. I have php interwoven in this javascript script as follows:
<script>
<?php
$json_string = json_encode(array("agent_table" => "<span style='float: left;'></span>"));
?>
var response = $.parseJSON('<?php echo $json_string; ?>');
</script>
But parseJson is complaining of an error. The error disappears when I remove the styling from the span.
The error is 'Unexpected identifier'. This is in Chrome.
You have ' characters in your data. These will continue to be represented as literal ' characters in the JSON.
You are embedding your JSON directly into a JavaScript string, and that string is delimited by ' characters. The first ' that appears as data in the JSON will terminate the JS string.
This is a general problem when embedding on data format in another. You are embedding JSON in JavaScript in HTML.
Your options:
Replace every instance of ' in the JSON with \' (so they mean "Apostrophe" instead of "End of JS string")
Treat the JSON as a JavaScript object literal instead of trying to munge it into a string which you run it through a JSON parser.
The latter option is the sane one (so long as your goal doesn't involve proving that PHP can generate valid JSON).
var response = <?php echo $json_string; ?>;
You don't need to worry about further escaping for inserting into the HTML because the only sequence you need to worry about (inside a script element) is </script> and PHP's json_encode will output <\/script> for that anyway.
May be it?
<script>
<?php
$json_string = json_encode(array(
"agent_table"=> '<span style="float: left;"></span>'
));
?>
var response = <?php echo $json_string;?>;
</script>
try it!!!
<script>
<?php
$json_string = json_encode(array('agent_table' => addslashes('<span style="float: left;"></span>')));
?>
var response = $.parseJSON('<?php echo $json_string; ?>');

PHP/Querypath get value of Javascript variable

I am trying to pass HTML using QueryPath. I would like to get the value of a Javascript variable in the HTML. Like this:
<script type="text/javascript">
var base_url = "http://www.exampleurl.com/";
var room_id = "357"; //I want to get the value of room_id
var selected_room_button = "";
</script>
I want to get value of Javascript variable *room_id* which is 357
How can I achieve this?
Even if not using QueryPath, are there any other HTML parsers that can enable me to do this kind of parsing?
You can use a regular expression. This code will return the room id in your example.
<?php
$html = '
<script type="text/javascript">
var base_url = "http://www.exampleurl.com/";
var room_id = "357"; //I want to get the value of room_id
var selected_room_button = "";
</script>';
$pattern = '/var room_id = "(.*)";/';
preg_match($pattern, $html, $matches);
$room_id = $matches[1];
But there is no general solution as a variable may have been defined twice, or have been defined in different scopes.
If you don't need to extract other content beside the row_id I would see no reason for using a HTML parser. It would just slow down things. Also please expect the HTML parser not being a Javascript parser! The HTML parser would just being used to extract the unparsed content between <script> </script> tags - as a string. You would need a regex again to extract the row_id.

transfer a Variable from php to js

I got really confused when i tried to transfer variables from php to js.
everything is fine when i try to get value using an id
for example:
var name = $("#name").val();
but my question is, if i want to convert for example this variable:
$id = 182938; //the id of the user
to this variable:
var id;
this question might be dumb... maybe easy for you, but not for me :p
I have looked it up and only found something like this anywhere i looked for:
<?php
$number = rand();
?>
<script language="javascript">
var num = <?php echo $number ?>
</script>
Does it have the same affect as passing down the value?
Thanks!!
Not quite. Encoding as JSON will ensure that it is a valid JavaScript literal.
var num = <?php echo json_encode($number) ?>
what the code does is:
<?php
$number = rand(); //assign random number to $number. let's say it's "3"
?>
//then these are printed on the page normally
<script language="javascript">
var num = <?php echo $number ?> //the $number is echoed at this position
</script>
and then the browser receives:
<script language="javascript">
var num = 3;
</script>
You have to generate syntactically VALID javascript. PHP can echo text into ANY part of the page it's generating, but that doesn't necessarily mean it's actually USABLE text. In your case, you've forgotten a ;, so your generated javascript is actually a syntax error:
var num = <?php echo $number ?>;
^--- missing
The same sort of thing occurs when you're outputting text. Consider where you're storing someone's name into a variable:
<?php
$name = "Miles O'Brien"; // <-- note the single quote
?>
<script>
var name = <? php echo $name ?>;
</script>
This LOOKS ok, but it'll actually generate yet another syntax error:
var name = Miles O'Brien;
there's no quotes around the whole string, and the embedded quote will START a string in javascript, leading the JS interpreter to complain about an undefined variable "Miles", an undfined variable "O", and an unterminated string literal.
Instead, the PHP should have been:
var name = <? echo json_encode($name) ?>;
The JSON encapsulation guarantees that you're embedding syntactically valid Javascript values.

Passing parameters to Javascript using PHP

I have the following line of code:
My Tweets!
Now while this is working perfectly fine the following line is not:
My Tweets!
Can anyone help me out why it is not working and suggest any changes? The variable I want to pass to the Javascript function is a PHP variable. I have tried the PHP with single quotes and double quotes but it is not working.
You need quotes for both the php side and the Javascript side. You've only got php quotes there.
My Tweets!
looks weird but it should work, though I'm no php expert. Note that if there's any chance that "myid" (on the php side) might contain user-supplied data (like, something that came from an <input> field at some time), or if it's otherwise unpredictable, then it has to be put through something on the server side to make sure that the resulting tag is "clean".
I usually do as following:
<script>
var jsvar = <?=json_encode($php_var)?>;
</script>
After that I can use jsvar under the javascript codes. And for readability I usually place all those assignments in an own script tag.
What you gain by using <?=json_encode($php_var)?> is that you won't need to go on escaping, and it works for arrays and hashes as well as strings, numbers etc...
For example, following php code:
<?php
$php_string = "hello";
$php_array = array( 'a', 'b', 'c' );
$php_hash = array( 'a' => 1, 'b' => 16, 'c' => 42 );
$php_number = 123;
$php_bool = false;
$php_null = null;
?>
<script type="text/javascript">
var js_string = <?=json_encode($php_string)?>;
var js_array = <?=json_encode($php_array)?>;
var js_hash = <?=json_encode($php_hash)?>;
var js_number = <?=json_encode($php_number)?>;
var js_bool = <?=json_encode($php_bool)?>;
var js_null = <?=json_encode($php_null)?>;
</script>
produces the following result:
<script type="text/javascript">
var js_string = "hello";
var js_array = ["a","b","c"];
var js_hash = {"a":1,"b":16,"c":42};
var js_number = 123;
var js_bool = false;
var js_null = null;
</script>
You forgot to Quote your answer. You are echoing the string OK, but you need to ' ' the response so JavaScript will know it's a string. You can use ' or \"
My Tweets!
Uses short echo thing.

How do I use PHP variables as values for the <script> tag when rendering jQuery code in my CakePHP view?

I m new to CakePhp and JQuery.
I am getting an error in using the cakephp code inside my JQuery.
My code
<script type="text/javascript">
$(document).ready(function(){
var attributeid;var fieldname;
$("#"+<?=$r['Attribute']['id'];?>).change(function () {
fieldname=<?=$r['Attribute']['label'];?>;
alert(fieldname);//this show me that undefined
attributeid=<?=$r['Attribute']['id'];?>;
alert(attributeid);//But this works
});//attribute change
});//ready function
if I echoed ($r['Attribute']['label'];) this value is coming inside my <?php ?>.
But not inside my JQuery.
Note :
attributeid=<?=$r['Attribute']['id'];?>;
alert(attributeid);//But this works
Error:
Name is not defined
fieldname=name;
alert(fieldname);
You are not thinking about how this is translating over once the variables are echoed.
If you have a variable $x with the contents "test", doing this:
var x = <?=$myvar?>;
Will result in:
var x = test;
This is not valid (unless test is a variable) because you need quotations around it to make it a string:
var x = "<?=$myvar?>";
Which then results in the valid:
var x = "test";
The reason it works with the other variable is because you are echoing an ID, which is an integer:
var x = <?=$myid?>;
Would translate to:
var x = 5;
Which is perfectly valid.
All this being said, you should put all the stuff you want to send over to Javascript in an array and call json_encode on it to easily and safely print the values over. Without it, you have to worry above about escaping quotes in the string and such.

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