Preselect table values in the system configuration

Question

I used this example to create my own table with configuration in admin. Now I'm trying to figure out how to preselect my saved values on page loads. I have this table now:

For preselecting this example uses _prepareArrayRow()

This is value from core_config _data:

a:4:{s:18:"_1486995392381_381";a:3:{s:12:"m2_attribute";s:16:"required_options";s:13:"chq_attribute";s:14:"CustomDecimal1";s:9:"push_once";s:5:"false";}s:18:"_1486995402858_858";a:3:{s:12:"m2_attribute";s:14:"fabric_content";s:13:"chq_attribute";s:6:"Rental";s:9:"push_once";s:4:"true";}s:18:"_1486995407176_176";a:3:{s:12:"m2_attribute";s:9:"fabricfit";s:13:"chq_attribute";s:13:"CustomNumber3";s:9:"push_once";s:4:"true";}s:17:"_1486995414029_29";a:3:{s:12:"m2_attribute";s:17:"short_description";s:13:"chq_attribute";s:17:"ItemCustomNumber6";s:9:"push_once";s:5:"false";}}

This is how unserialized value looks like:

Array
(
    [_1486995392381_381] => Array
        (
            [m2_attribute] => required_options
            [chq_attribute] => CustomDecimal1
            [push_once] => false
        )

    [_1486995402858_858] => Array
        (
            [m2_attribute] => fabric_content
            [chq_attribute] => Rental
            [push_once] => true
        )

    [_1486995407176_176] => Array
        (
            [m2_attribute] => fabricfit
            [chq_attribute] => CustomNumber3
            [push_once] => true
        )

    [_1486995414029_29] => Array
        (
            [m2_attribute] => short_description
            [chq_attribute] => ItemCustomNumber6
            [push_once] => false
        )

)

Any help will be appreciated!

Answer 1

Finally I figured out how to make it. I created repo and you can check test module there. The answer for this question is in file Block/System/Config/Form/Field/Active.php in method _prepareArrayRow()