I have seen this answer (and a couple others as well) and it provides an understandable way of accessing a PHP array. But in the example, the PHP and the JavaScript are in the same file.
However, I can not write Javascript in my PHP file for some reasons, and what I am rather doing is invoking the JS present in another file. So I need to access an array from the PHP in the JS file. How can I do that?
I prefer it without AJAX (if possible) because I have not yet started learning AJAX.
You could use a JSONP approach:
Make your PHP file output your data wrapped in a function call - something like this:
callback(
['your', 'data', 'here']
);
To do this with a PHP variable you can do this:
callback(<?php echo json_encode($data) ?>);
Then in your JavaScript file do this:
function callback(data) {
alert( data.join(' ') ); // will alert 'your data here'
}
In your HTML file just include the above JS file and afterwards include another script tag that points to your php file:
<script src="/path/to/local.js"></script>
<script src="http://yourserver.com/path/to/server.php"></script>
The browser will grab the first file, and evaluate the function declaration. Then it will grab the second file, and see that it is a function invocation and immediately execute your function with the data as the argument.
JS part. But I do not understand callback( ['your', 'data', 'here'] ); part. What is the [...] construct? What should I read up on to understand this?<script> tags in HTML because I can not add anything to <head> and I can not add any <script> tags anywhere. I can just use an API function to load a JS function from an external file.
callback([...]) is just javascript that is outputted from your PHP script. You can add the script tag anywhere in your HTML if you want it doesn't have to be in the HEAD.[] syntax is just a JavaScript array literal.A quick and dirty solution would be to make your JavaScript file a PHP file and pass all the variables you need when including the script:
<script type="text/javascript" language="javascript" src="./script.php?var=<?php print(json_encode($var)); ?>"></script>
In the JavaScript file you can use the PHP variables like so:
var a=JSON.parse(<?php print($_REQUEST['var']); ?>);
JSON class part of jQuery, rather than just JavaScript?