div onclick isn't working - php

Question

I'm trying to get the caption part of my slider to link to the respective article url on my wordpress site. I'm pretty sure I found the section in the plugin code I think needs to be edited, but when I try to do the following:
<?php
echo "<div id='" . $sl_caption . "' class='nivo-html-caption'>" . $sl_htmlcaption . onclick="location.href='$url';"</div>";
?>
I get "syntax error, unexpected T_STRING, expecting ',' or ';" showing up in my slider, and the rest of my site not working. I've tried many variations of what I've tried to do here, but I can't seem to find one that works.
Here's the original entire slider code if it's helpful: http://pastebin.com/4nKxXkSa

Answer 1

Your opening/closing of double-quotes is wrong : in PHP, strings must be enclosed in either quotes or double-quotes ; and if you want to put a double-quote in a double-quotes enclosed string, you have to escape it with a \.
For example, you need to open a quote or double-quote before onclick, as this is part of a string.
Also, your onclick should be inside the <div ...> tag, and not between <div> and </div>.
In the end, your PHP code would look a bit like this (I've set up hard-coded values for the variables, to help with testing) :
$sl_caption = 'ID';
$sl_htmlcaption = 'HTML';
$url = "URL";
echo "<div id='"
. $sl_caption
. "' class='nivo-html-caption' onclick=\"location.href='$url'\">"
. $sl_htmlcaption
. "</div>"
;
And you'd get the following HTML as output :
<div id='ID' class='nivo-html-caption' onclick="location.href='URL'" >HTML</div>

Answer 2

Your string quotes are not correctly placed. Try this
echo "<div id='" . $sl_caption . "' class='nivo-html-caption'>" . $sl_htmlcaption . "onclick=\"location.href='$url';\"</div>";

Answer 3

The problem is what it says - "onclick" isn't a quoted string in your example (T_STRING in PHP). Everything you join together (concatenate) in a string needs to be either a) a string in quotes (single or double), b) something that can be converted to a string or c) a variable/constant/function call.
If you didn't have that error then your current example would also have the "onclick" as the content of the tag, rather than an attribute on the tag. What I think you want is:
<?php
echo "<div id='" . $sl_caption . "' class='nivo-html-caption' onclick='location.href=\'" . $url . "\''>" . $sl_htmlcaption . "</div>";
?>
If you want standard HTML attributes then you'd normally use double-quotes, which would give you:
<?php
echo '<div id="' . $sl_caption . '" class="nivo-html-caption" onclick="location.href=' . $url . '">' . $sl_htmlcaption . '</div>';
?>
Also, is there any reason why you're using an onclick to set the current location rather than a normal <a href>?

Answer 4

the qoute isn't the only problem. The onclick is also out of the div element's properties. It must be (changes the doubles for singles to make it more clear):
echo '<div id="' . $sl_caption . '" class="nivo-html-caption" onclick="location.href=' . $url . ';">' . $sl_htmlcaption . '</div>';

Answer 5

Your quotes are the problem. It should be:
echo "<div id='" . $sl_caption . "' class='nivo-html-caption'>" . $sl_htmlcaption . "onclick=\"location.href='$url';\"</div>";
You needed double quotes to start the string again after the concatenation operator (.), but then you need to escape the double quotes inside this string wit a blackslash so the PHP interpreter won't think the string has ended too soon.
And as Pascal pointed out, the onclick attribute should actually be inside the stating div tag anyway:
echo "<div id='" . $sl_caption . "' class='nivo-html-caption'onclick=\"location.href='$url';\">" . $sl_htmlcaption . </div>";
Using interpolation may make things easier for you also. When using double quotes to delimit a string you can insert variables' values using curly brackets ({}) like this:
echo "<div id='{$sl_caption}' class='nivo-html-caption'onclick=\"location.href='{$url}';\">{$sl_htmlcaption}</div>";
This way you only have to open and close the string once (at the beginning and end).
Beware:
You cannot interpolate function calls directly. You can either concatenate like "<p>".strlen($x)."</p>" or store the result in a variable and the interpolate like before; "<p>{$result}</p>".
You'll still have to escape double quotes within the string though.