WP-API - Post by Category

Readme.md

Use the above function in functions.php file to get all posts under a particular category by that category slug

Access url https://your-site.com/wp-json/idapi/v1/posts/{category-slug-without-braces}

functions.php

add_action('rest_api_init', function () {
  register_rest_route( 'idapi/v1', 'posts/(?P<category_name>[-\w]+)',array(
                'methods'  => 'GET',
                'callback' => 'get_posts_by_category_name'
      ));
});

function get_posts_by_category_name($request) {
	
	$args = array(
		'category_name' => $request['category_name']
	);

    $posts = get_posts($args);
    if (empty($posts)) {
    	return new WP_Error( 'empty_category', 'there is no post in this category', array('status' => 404) );
    }
	
	$post_data = array();
	$i = 0;
    foreach( $posts as $post) {
        $post_id = $post->ID;
        $post_title = remove_html_comments($post->post_title);
        $post_content = remove_html_comments($post->post_content);
		$post_data[ $i ][ 'id' ] = $post_id;
        $post_data[ $i ][ 'title' ] = $post_title;
        $post_data[ $i ][ 'content' ] = $post_content;
		$i++;
    }

    $response = new WP_REST_Response($post_data);
    $response->set_status(200);

    return $response;
}

function remove_html_comments($content = '') {
	return preg_replace('/<!--(.|\s)*?-->/', '', $content);
}