Get tags specific category

I use this code to get tags from category.

get all tags from category

I want to display in the category page the specific tags. I have 8 categories and this is my code:

        <?php if (is_category('10')) { ?>
    <?php $args = array(
  'categories'        => '10'
);
$tags = get_category_tags($args);
$content .= "<ul>";
foreach ($tags as $tag) {
  $content .= "<li><a href=\"$tag->tag_link\">$tag->tag_name</a></li>";
}
$content .= "</ul>";
echo $content; ?> 

    <?php } elseif (is_category('4')) { ?>
<?php $args = array(
  'categories'        => '4'
);
$tags = get_category_tags($args);
$content .= "<ul>";
foreach ($tags as $tag) {
  $content .= "<li><a href=\"$tag->tag_link\">$tag->tag_name</a></li>";
}
$content .= "</ul>";
echo $content; ?> 
.....

Do that for each category I thinks is not the best way, any idea?

If you use get_terms(), then you can retrieve all terms for a given taxonomy (this includes category as well as post-tag).

To get the category on a category archive page, you can use

get_category( get_query_var( 'cat' ) )

which will give you an object of the currently displayed cat archive page.

So the actual term list will be available with something like the following:

$terms = get_terms(
     get_category( get_query_var( 'cat' ) )
    ,array(
         'fields'       => 'ids'
        ,'hierarchical' => true
        ,'hide_empty'   => false
        ,'pad_counts'   => true
     )
);

$term_links = array();
foreach ( $terms as $term )
{
    $link = get_term_link( $term, $taxonomy );

    ! is_wp_error( $link ) AND $term_links[] = sprintf(
             '<a href="https://wordpress.stackexchange.com/questions/75017/%s" rel="tag">%s</a>'
            ,esc_url( $link )
            ,$term->name
    );
}
// Now do something clever with $term_links
// For example:
! is_empty( $terms ) AND printf(
     '<ul>%s</ul>'
    ,implode( "", $term_links )
);