is_page condition not working

Question

The is_page() with post id, post slug isn't working. Below is the code i have been using in divi child theme at the end of the functions.php file.

function addingcattocatlist($cat_list){

        if ( is_page('blog') ) {
            $cat_list = 'blog: '. '' .$cat_list;
        }   
        return $cat_list;
}
add_filter('the_category' , 'addingcattocatlist', 10);

Answer 1

Try this:

if ( is_front_page() && is_home() ) {
  // Default homepage
} elseif ( is_front_page() ) {
  // static homepage
} elseif ( is_home() ) {
  // blog page
} else {
  //everything else
}

Source: http://codex.wordpress.org/Conditional_Tags

Answer 2

OK @Muyassir S. - we are missing some information to understand the problem.

We basicly dont know if the "page" you are talking about is a category page, Your home page or a custom page - meaning: which file is being used to show that blog?

here are two possible solutions.

If we are talking about a category / page with slug:

if(is_category('blog')) {
   // add whatever you want here
}

• should be placed inside category.php template

If you went to: Settings > Reading
and set the posts page over there then its a page and can be accesses like this.

$blogPgid = get_option('page_for_posts');

if(get_the_ID() == $blogPgid) {
       // add whatever you want here
}

• should be placed inside page.php template.

Let me know if this helps

EDIT 1: here is what i would do.

1st. Just copy page.php in your theme and name the new copy page-blog.php Now, add a in the top of that page these tag (above everything).

<?php
/*
Template Name: Blog Page
*/
?>

2nd. go back to that page in WP admin and pick that page template. Now you have a page / file that you can control and add whichever specific stuff you'd like.

Answer 3

functions.php is processed way before you can know which page is being loaded. Instead of assigning value to variable put your code into function and use that function in page.php template.

Why isn't is_page working when I put it in the functions.php file?