Getting PHP data from MySQL DB inside script tag for use with Javascript

Question

This is similar to PHP generated content inside Javascript breaking script, however I'm not able to understand where I'm wrong.

Here is the brief. I'm trying to output 10 strings from MySQL DB into a javascript array s, (s[1] to s[10]) (stored in one MySQL table under columns pt1 to pt1 - info so code is understandable to all). (Note $apos is just the apostrophe string - not a concern here).

<?php 
echo "<script>\n";
echo "var s = [];\n";
 for($i=1;$i<=10;$i++) {
 echo "s[".$i."] = ".$apos.$r['pt'.$i].$apos.";\n"; 
 } 
echo "</script>";
 ?>

It produces the right code when I look at the source by 'View Source' in browser:

<script>
var s = [];
s[1] = 'a';
s[2] = 'b';
.
.
s[10] = 'j';
</script>

However, this doesn't work as a script (meaning if I check in Google developer tools, and I click on content inside the 'script' tag elements, it is told to be 'text', and not 'script' in the bar below).

However if I remove the PHP, and manually write the whole script the same way, it works just fine. I have tried removing the \n linebreaks in the PHP code, but still the same problem.

Something in PHP is breaking the script. Can you help?

My personal preference is var s=<?php echo json_encode($info);?>; — Passerby
– Passerby, Commented Sep 4, 2014 at 9:09
@jeff I've clarified that point in the question now. Let me know if its still unclear. — Kshitij
– Kshitij, Commented Sep 4, 2014 at 9:15
When you say "look at the source file" do you mean using "view source" at the browser? — Bob Brown
– Bob Brown, Commented Sep 4, 2014 at 9:19
@Bob Yes. The problem is very similar in spirit to the earlier problem link which I've posted in the start of the question. — Kshitij
– Kshitij, Commented Sep 4, 2014 at 9:22

Anax · Accepted Answer · 2014-09-04 09:30:16Z

0

My best guess is that one (or more) of your strings contains a character (such as the apostrophe) which breaks the PHP output. Still the best solution was already prosposed by Passery in your comments section:

echo '<script>';
echo 'var s = ' . json_encode($info);
echo '</script>';

answered Sep 4, 2014 at 9:30

Anax

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1 Comment

Kshitij Over a year ago

I agree with Passerby's answer, and it works. But whether the apostrophe is breaking it or not I'm not certain, as the 'View source' files for the working and non-working codes are exactly the same!

Bob Brown · Accepted Answer · 2014-09-04 10:15:14Z

I think you may have been misreading the developer tools. When I look closely at Chrome, it does indeed identify your script as text, possibly because the default type is text/javascript. Putting an explicit type declaration on the <script> tag made no change.

However, when I add echo "alert('s[1]='+s[1]);"; after the for loop, the alert displays, and I am able to see the values of the other s[i] with the debugger.

In other words, I think your generated JavaScript worked all along.

I know you've already fixed the problem another way. I post this answer only in case it may help others.

Here is what I used for testing:

<?php 
$a = "-abcdefghij";
$apos="'";
echo "<script type=\"text/javascript\">";
echo "var s = [];";
for($i=1;$i<=10;$i++) {
 echo "s[".$i."] = ".$apos.$a[$i].$apos.";\n"; 
} 
echo "alert('s[1]='+s[1]);";
echo "</script>";
?>

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