wp_localize_script is not accepting dynamic value - wordpress

Question

*Context
I am new to WordPress plugin development and I have just started developing one. Which is basically a blog slider plugin. The concept is very simple. The user can use shortcodes with parameters to determine which posts and how many posts to be shown. There is no admin settings page for changing the appearance of the slider though, but I'll work on that. The user have to use shortcode whenever the slider is needed.
The development part is also simple. I am checking the parameters that the user passes through the shortcode. And then a query runs and returns an array of posts and then displays the structure. Very simple.
*Problem
Now I am trying to make the plugin options more dynamic (via shortcode) i.e. the user can control whether the slider should auto-play or not, loop should be enabled or not, pause on hover, dots/nav hide or show etc. I am using owl carousel for this slider. So that means I have to change the attributes of the slider in JavaScript file.
The basic idea is to take the parameters from function's $atts array, and pass it to the JavaScript file. I know this can be accomplished using wp_localize_script, but I cannot figure out how.
Here is my code to make things more clear.
mainfile.php
add_shortcode( 'sp-slider', 'sp_slider_get_posts');
function sp_slider_get_posts( $atts ) {
$values = shortcode_atts( array(
'number' => '-1',
'category-id' => '', //DEFAULT VALUE null, WILL BE REPLACED ONCE USER DECLARES IN SHORTCODE
'category-name' => '',
'orderby' => '',
'order' => '',
'include-posts' => '',
'exclude-posts' => '',
'author-id' => '',
'author-name' => '',
'autoplay' => ''
), $atts );
if( !empty($values['number']) ||
!empty($values['category-id']) ||
!empty($values['category-name']) ||
!empty($values['orderby']) ||
!empty($values['order']) ||
!empty($values['include-posts']) ||
!empty($values['exclude-posts']) ||
!empty($values['author-id']) ||
!empty($values['author-name']) ||
!empty($values['autoplay'])) {
$args = array(
'numberposts' => $values['number'],
'cat' => $values['category-id'],
'category_name' => $values['category-name'],
'orderby' => $values['orderby'],
'order' => $values['order'],
'include' => $values['include-posts'],
'exclude' => $values['exclude-posts'],
'meta_key' => '',
'meta_value' => '',
'post_parent' => '',
'author' => $values['author-id'],
'author_name' => $values['author-name'],
'post_status' => 'publish',
'suppress_filters' => true,
'fields' => '',
);
$autoplay = $values['autoplay']; //GET AUTOPLAY VALUE. NO IDEA HOW TO USE IT. SO I TRIED THE FOLLOWING
// THE FOLLOWING FUNCTION HOLDS THE wp_localize_script FUNCTION, WHICH IS DECLARED AT THE END OF THIS CURRENT FUNCTION sp_slider_get_posts.
sp_carousel_settings($autoplay); //PASSING THE USER INPUT
$posts_array = get_posts( $args );
if( !empty( $posts_array ) ) {
$output = "<div class='sp-slider-wrapper'>";
$output .= '<div class="owl-carousel owl-theme">';
foreach( $posts_array as $post ) {
include( "includes/inc_slider_section.php"); // ALL THE SLIDER STRUCTURE IS IN DIFFERENT FILE WHICH IS INCLUDED HERE
}
$output .="</div>";
$output .="</div>";
}
return $output;
}
}
// HERE IS sp_carousel_settings() DECLARATION
function sp_carousel_settings( $autoplay ) {
$carousel_settings = array( 'autoplay' => $autoplay);
wp_localize_script( 'sp_main_js', 'carousel_settings', $carousel_settings );
}
add_action( 'wp_enqueue_scripts', 'sp_carousel_settings' );
mainjs.js
$(document).ready(function() {
...
...
var autoplay= '';
if(typeof carousel_settings !== 'undefined') {
autoplay = carousel_settings.autoplay;
}
else {
autoplay = false;
}
$('.owl-carousel').owlCarousel({
loop:true,
autoplay:autoplay,
autoplayTimeout:2000,
autoplayHoverPause:true,
...
...
}
})
This doesn't work. Here I would like to mention that, in add_action() function, if i put wp_footer instead of wp_enqueue_scripts, it adds the script to the footer of the page (I have checked it by viewing the source) but the autoplay value is null.
Another thing i would mention is that, in sp_carousel_settings() function, instead of passing the $autoplay variable, if I write any static value like this $carousel_settings = array( 'autoplay' => true);, it works.
*I tried echoing out $autoplay inside sp_carousel_settings() and it prints the value! But does not get to the js file.
*I tried checking the value of $autoplay and pass a hardcore sting inside wp_localize_script like
function sp_carousel_settings( $autoplay ) {
if( $autoplay == "true" ) {
echo "Inside!!!";
$carousel_settings = array( 'autoplay' => true);
}
else {
echo "Outside!!!";
$carousel_settings = array( 'autoplay' => false);
}
wp_localize_script( 'sp_main_js', 'carousel_settings', $carousel_settings );
}
add_action( 'wp_footer', 'sp_carousel_settings' );
Does not work. EVEN it prints out "Inside!!!" but does not pass true in autoplay. The value is always false.
*I have registered the js file in the beginning of the plugin, where the plugin activates and gets initialized. Like this
function sp_slider_include_css_js() {
...
...
wp_register_script('sp_main_js', plugins_url('assets/js/main.js',__FILE__));
wp_enqueue_script('sp_main_js');
...
...
}
add_action( 'wp_footer','sp_slider_include_css_js');
*I have searched internet for help but was unable to find. Any reference will be appreciated.
*I know that I might be using the function in an improper way. I am clueless (and new to this).

Answer 1

Have to do some changes like,
Step 1:
function sp_carousel_settings() {
wp_register_script( 'sp_main_js', 'you/file/path/here', array( 'jquery' ), '1.0', true);
}
add_action( 'wp_enqueue_scripts', 'sp_carousel_settings' );
Step 2:
add_shortcode( 'sp-slider', 'sp_slider_get_posts');
function sp_slider_get_posts( $atts ) {
.....
$carousel_settings = array( 'autoplay' => $autoplay);
wp_localize_script( 'sp_main_js', 'carousel_settings', $carousel_settings );
wp_enqueue_script( 'sp_main_js' );
......
}