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PHP call to javascript localStorage.setItem special Chars fails

Posted on 2014-04-03
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Last Modified: 2014-04-13
The code below is having a problem with the special characters. Does anybody know why?

<script type="text/javascript">
function enter_user_email(str){
   localStorage.setItem('user_email', str);
}
</script>

<?php
$usr_email= "aaaaaa@bbbbb.xx";
echo "<script type=\"text/javascript\">enter_user_email(\"$usr_email\");</script>";
?>
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Question by:Solenthaler
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10 Comments
 
LVL 109

Expert Comment

by:Ray Paseur
ID: 39974645
What special characters?  Is there some confusion about UTF-8 encoding, maybe?
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Author Comment

by:Solenthaler
ID: 39974731
If $usr_email= "aaaaaa@bbbbbxx"; or  "aaaaaabbbbb.xx"; the call to the function succeeds.
However if $usr_email = "aaaaaa@bbbbb.xx"; :
 -> the PHP call to the javascript function is failing and it echoes the following three chars: "); (the 3 last chars from to call code) I think, because of the special chars in $usr_email - the call fails. If i delete the "." and/or the "@" the call works perfect.
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LVL 109

Accepted Solution

by:
Ray Paseur earned 300 total points
ID: 39974802
I think there must be something else in play.  I cannot duplicate the failure.  
http://iconoun.com/demo/temp_solenthaler.php

Install this and run it to see what I'm seeing.

<?php // demo/temp_solenthaler.php
error_reporting(E_ALL);

/*
 * THE PHP VARIABLES FOR OUR SCRIPT
 */
$usr_email= "aaaaaa@bbbbb.xx";

/*
 * THE JAVASCRIPT SNIPPETS
 */
$js1 = <<<EOD
<script type="text/javascript">
function enter_user_email(str){
    localStorage.setItem('user_email', str);
}
</script>
EOD;

$js2 = <<<EOD
<script type="text/javascript">
$(document).ready(function(){
    $("#zap").click(function(){
        foo = localStorage.getItem('user_email');
        alert('user_email: ' + foo);
    });
});
</script>
EOD;

$js3 = <<<EOD
<script type="text/javascript">enter_user_email("$usr_email");</script>
EOD;


/*
 * CREATE OUR WEB PAGE IN HTML5 FORMAT
 */
$htm = <<<HTML5
<!DOCTYPE html>
<html dir="ltr" lang="en-US">
<head>
<meta charset="utf-8" />
<meta name="robots" content="noindex, nofollow" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<title>HTML5 Page in UTF-8 Encoding</title>

$js1
$js2

</head>
<body>

$js3

<div id="zap">Click Here To See LocalStorage user_email</div>

</body>
</html>
HTML5;

/*
 * RENDER THE WEB PAGE
 */
echo $htm;

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Author Comment

by:Solenthaler
ID: 39975675
Hi Ray
incredible - thanks for this! I will build up a Demo.
Some environment in my example:
 -> the code is in a self made module for Joomla 2.5 and will use Joomlas user management. Will come back to it on sunday.
Cheers Roland
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LVL 86

Expert Comment

by:CEHJ
ID: 39975948
The other thing is that one can't assume that localStorage is available. e.g. it's been known for it to fail on Safari when private browsing is enabled. Maybe test first:

function isLocalStorageSupported() {
    var result = true;
    try {
	localStorage.setItem("foo", "bar");
	result = (localStorage.getItem("foo") == "bar");
    } catch (error) {
	result = false;
    }
    return result;
}

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LVL 33

Assisted Solution

by:Slick812
Slick812 earned 100 total points
ID: 39976262
greetings Solenthaler, Writing from PHP into Javascript with echo , requires More care than writing to page HTML output, For me I always use the OPPOSITE quotes (single ' -double ") when going from PHP to JS, you might try -

$usr_email= "aaaaaa@bbbbb.xx"; // if " here
//use a single ' in JS -
echo '<script>enter_user_email("'.$usr_email.'");</script>';
// be careful, look at source code to see the actual result in JS


= = = = = = = = = = = = = = = =
for many years (forever just about) the type in
<script type="text/javascript">
   has been UNNECESSARY , so leave it out, use,  <script>
0
 
LVL 109

Expert Comment

by:Ray Paseur
ID: 39976669
@CEHJ: I think that's a good idea - to test for support.  Trouble is, I don't know how to "degrade gracefully" if localStorage is not there.  Maybe set a cookie?  Or create a nag-page?  Not sure of the best practices in that case.

@Slick812: The example script parses correctly, but you're right that the quote marks can be confusing.  That's why I favor the use of HEREDOC notation (as shown above).  The quotes and apostrophes in a HEREDOC block have no meaning to PHP so you can concentrate on getting the script right for JavaScript, only.
0
 
LVL 86

Assisted Solution

by:CEHJ
CEHJ earned 100 total points
ID: 39976706
Maybe set a cookie?
Yes, that's a possibility although that too will need to be tested for. It just so happens i've been having problems with both recently (though the bar is higher for me - the web pages are offline)
0
 
LVL 109

Expert Comment

by:Ray Paseur
ID: 39976741
Kickstarter.com uses a nag-page if you don't accept their cookie, and it seems to work in a way that makes sense.  But sometimes I feel like clients who don't return cookies or run javaScript are so far out on the edge that we can ignore them without any measurable business impact.  Given that you can't use FB, Twitter, etc., without that functionality it seems like the number of people who disable these things is pretty small.  But I've not seen a survey recently.
0
 

Author Closing Comment

by:Solenthaler
ID: 39997323
Hi experts
finally i made it (with your help - of course). Surprisingly a Joomla Plugin "e-mail cloake" caused the problem. The e-mail string has on the flight been replaced by the encrypted string.  {emailcloak=off} did the trick. Thanks a lot.
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