How to show only specific category post by user role without plugin and restrict all other cats

If you’re using global loop for displaying the posts, then you can easily modify which posts are shown using pre_get_posts action.

function restrict_categories_for_user( $query ) {
    if ( ! is_admin() && $query->is_main_query() && get_current_user_id() ) {
        $user = wp_get_current_user();
        if ( in_array( 'viewer_a', (array) $user->roles ) ) {
            // The user has the "viewer_a" role
            $query->set( 'category_name', 'cat_A' );  // <- use category slug here
        }
        if ( in_array( 'viewer_b', (array) $user->roles ) ) {
            // The user has the "viewer_b" role
            $query->set( 'category_name', 'cat_B' );  // <- use category slug here
        }
    }
} 
add_action( 'pre_get_posts', 'restrict_categories_for_user' );

I assume that you want to restrict which posts can be viewed by these users on front-end. If you want to restrict posts visible in back-end, then you’ll have to change this condition if ( ! is_admin() && $query->is_main_query() && get_current_user_id() ) { accordingly…

Related Posts:

  1. How to add another user to this remove_menu function?
  2. remove_action on after_setup_theme not working from child theme
  3. Remove Actions/Filters added via Anonymous Functions
  4. Trying to use add_action and do_action with parameters
  5. Check if post is being published for the first time, or is an already published post being updated
  6. WordPress Theme Update Action?
  7. add_action in a function, is it possible?
  8. Using a private method as an action callback from within a class
  9. Add action hook conditionally – only when home.php in use
  10. How to manually activate user in dashboard only by admin
  11. Using add_filter() in Widgets
  12. Apply custom role capabilities to administrator (without plugin)
  13. How can I tell if I’m on a login page? [duplicate]
  14. Roles & capabilities GUI that does not create separate table
  15. Change meta tags programatically
  16. Convert hyphen to underscore in permalinks
  17. How to hook into the quick edit action?
  18. Reuse variable in hook callback
  19. Call to undefined add_action() in theme’s functions.php
  20. WooCommerce add_action hook results in 500 error
  21. Add a new subscriber role using a function
  22. Custom roles can’t access to wp-admin
  23. Custom registration URL lost when user makes signup mistake
  24. Custom function for specific user role
  25. How would go about if I just want a temporary function?
  26. Pass parameters to function through an action
  27. Accepted arguments value in hook functions
  28. How do I pass arguments for multiple functions hooked to a single action?
  29. How to properly add function called by action-hooked function to functions.php?
  30. Which action hook to use for function?
  31. Custom HTML in specific category single page and its descendant categories
  32. Modify a function without editing template
  33. Don’t delete a page if it holds users
  34. Toggle User Roles with button
  35. How do I add Bootstrap and LESS to my migrated WordPress site?
  36. How to change or add user role after getting post request data about pay? [closed]
  37. Is there an alternative to get_template_directory_uri()?
  38. Wait a result before enqueue
  39. Multiple Loops Meta Data
  40. Function added using `add_action()` not being called
  41. jQuery does not work
  42. Allow Contributor to edit their own posts after Adm aproval
  43. Override the WordPress core function wp_referer_field
  44. Modify post filter to set custom number of posts per page and exclude child posts
  45. Two functions with different arguments and add_actions, but identical code
  46. How to ignore posts in pre_get_posts?
  47. How to set default post editor based on role?
  48. I can’t seem to install Font Awesome locally [closed]
  49. Scripts not loading when using the wp_enqueue_scripts action
  50. Auto log in hook is requiring a page refresh
  51. problem loading stylesheets to wp_head dynamically
  52. current_user_can comma list vs OR (||) list
  53. Adding additional roles on registration
  54. How to properly refresh page after form action?
  55. 400 Bad Request – JavaScript App calling Custom wp-json endpoint
  56. The Capability to choose post/page template
  57. Changing where my author box is printed
  58. Insert Content Before div#main from the functions.php File
  59. Use add_action within template
  60. Problem in using Customizer
  61. Problem with custom function when I go back with the browser
  62. Replace admin header logo with an image
  63. New checkbox in custom widget isn’t saving data
  64. template_redirect action only firing if logged in
  65. Setting post_id for single.php based on URL without a redirect
  66. Custom user role still showing up after deletion, ideas?
  67. How to use wp_enqueue_script properly?
  68. Detect Ajax call inside pre_get_posts function
  69. Using get_terms for custom taxonomy in functions.php
  70. Issue passing action class to nested function. Admin Columns
  71. Allow user select role in wordpress default registration without plugin
  72. Does hook have an effect on increasing the page load?
  73. What is the earliest Hook a Script can use?
  74. How do I trigger WP CLI DB export using a PHP function?
  75. Remove check boxes and its label from screen option for custom role
  76. post value to function with Ajax and jQuery
  77. How do you insert code into the sidebar?
  78. How Do I Unhook This Parent Theme Function?
  79. Add Change role button for list of user in an event
  80. How to offset main query without affecting other queries and backend
  81. use add_action in a shortcode (gravity form – WordPress)
  82. wp_footer hook causing text to show on bottom of page
  83. Change user role based on total number of items ordered
  84. Remove all video attachment, both files and post/postmeta from database?
  85. WordPress hooks to call a function inside a construct
  86. True parameter but jquery register in header and not in the footer with wp_register_script
  87. Change the second role depending on the first
  88. Restrict certain roles registrations by domain
  89. Fatal error: Call to undefined function add_action() – an untouched problem
  90. Sending Messages Back to the Template After Processing?
  91. Pass arguments to function class with do_action()
  92. previous_post_link inside of a function?
  93. Multisite Admin Roles
  94. function to return comma separated list of meta values
  95. Welcome Mails based on user role
  96. Do something when user creates post (that’s pending)
  97. add variable to actions/functions across different files (woocommerce)
  98. Get all users from role and add to dropdown (select) – wordpress, javascript
  99. HELP: Code To Check Status And Write Debug Entry
  100. How to get variable from other function inside class function using add_action for Ajax call