Inject class in custom Field

Question

I created a backend configuration for my custom plugin

/app/code/Sostanza/LiveHelp/etc/adminhtml/system.xml

https://pastebin.com/2jwnYLwb

/app/code/Sostanza/LiveHelp/Block/Button.php

https://pastebin.com/myadtSZE

I need to get the value of a saved option and I already have a Helper class where I can read the value I need.

I have my helper in

/app/code/Sostanza/LiveHelp/Helper/Data.php

https://pastebin.com/JAUWX41c (Max 2 links with my reputation)

But if in the Button.php I add

Sostanza\LiveHelp\Helper\Data $data

The config section doesn't get rendered anymore I tried also to inject other stuff, but it doesn't work. Of course I ran "magento setup:upgrade" and deleted cache/generation folders.

Thank you so much

Answer 1

Make your code look like this:

protected $_helper;

public function __construct(
            Context $context,
            \Sostanza\LiveHelp\Helper\Data $helper,
            array $data = []
    ) {
     $this->_helper = $helper;
     parent::__construct($context, $data);
    }

And then you can use functions in your helper class like this:

$this->_helper->someRandomFunction();

So in general: you need to pass your helper into __construct() method, then you can use it.

Answer 2

Did you tried it with "\" in the beginning of "\Sostanza\LiveHelp\Helper\Data" ? Because it make a lot of difference.