Show only author's articles

smallerversion.php

// hide articles from contribs who don't own them

function show_author_posts_only($query) {
    global $user_level;

    if($query->is_admin && $user_level < 5) {
        global $user_ID;
        $query->set('author',  $user_ID);
        unset($user_ID);
    }
    unset($user_level);

    return $query;
}
add_filter('pre_get_posts', 'show_author_posts_only');

version0.php

// Show only posts related to current user
add_action('pre_get_posts', 'query_set_only_author' );
function query_set_only_author( $wp_query ) {
    global $current_user;
    if( is_admin() && !current_user_can('edit_others_posts') ) {
        $wp_query->set( 'author', $current_user->ID );
        add_filter('views_edit-post', 'fix_post_counts');
    }
}

// Fix post counts
function fix_post_counts($views) {
    global $current_user, $wp_query;
    unset($views['mine']);
    $types = array(
        array( 'status' =>  NULL ),
        array( 'status' => 'publish' ),
        array( 'status' => 'draft' ),
        array( 'status' => 'pending' ),
        array( 'status' => 'trash' )
    );
    foreach( $types as $type ) {
        $query = array(
            'author'      => $current_user->ID,
            'post_type'   => 'post',
            'post_status' => $type['status']
        );
        $result = new WP_Query($query);
        if( $type['status'] == NULL ):
            $class = ($wp_query->query_vars['post_status'] == NULL) ? ' class="current"' : '';
            $views['all'] = sprintf(__('<a href="%s"'. $class .'>All <span class="count">(%d)</span></a>', 'all'),
                admin_url('edit.php?post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'publish' ):
            $class = ($wp_query->query_vars['post_status'] == 'publish') ? ' class="current"' : '';
            $views['publish'] = sprintf(__('<a href="%s"'. $class .'>Published <span class="count">(%d)</span></a>', 'publish'),
                admin_url('edit.php?post_status=publish&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'draft' ):
            $class = ($wp_query->query_vars['post_status'] == 'draft') ? ' class="current"' : '';
            $views['draft'] = sprintf(__('<a href="%s"'. $class .'>Draft'. ((sizeof($result->posts) > 1) ? "s" : "") .' <span class="count">(%d)</span></a>', 'draft'),
                admin_url('edit.php?post_status=draft&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'pending' ):
            $class = ($wp_query->query_vars['post_status'] == 'pending') ? ' class="current"' : '';
            $views['pending'] = sprintf(__('<a href="%s"'. $class .'>Pending <span class="count">(%d)</span></a>', 'pending'),
                admin_url('edit.php?post_status=pending&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'trash' ):
            $class = ($wp_query->query_vars['post_status'] == 'trash') ? ' class="current"' : '';
            $views['trash'] = sprintf(__('<a href="%s"'. $class .'>Trash <span class="count">(%d)</span></a>', 'trash'),
                admin_url('edit.php?post_status=trash&post_type=post'),
                $result->found_posts);
        endif;
    }
    return $views;
}

version1.php

// Show only posts related to current user
add_action('pre_get_posts', 'query_set_only_author' );
function query_set_only_author( $wp_query ) {
    global $current_user;
    if( !current_user_can('editor') && !current_user_can('administrator') ) {
        $wp_query->set( 'author', $current_user->ID );
        add_filter('views_edit-post', 'fix_post_counts');
    }
}

// Fix post counts
function fix_post_counts($views) {
    global $current_user, $wp_query;
    unset($views['mine']);
    $types = array(
        array( 'status' =>  NULL ),
        array( 'status' => 'publish' ),
        array( 'status' => 'draft' ),
        array( 'status' => 'pending' ),
        array( 'status' => 'trash' )
    );
    foreach( $types as $type ) {
        $query = array(
            'author'      => $current_user->ID,
            'post_type'   => 'post',
            'post_status' => $type['status']
        );
        $result = new WP_Query($query);
        if( $type['status'] == NULL ):
            $class = ($wp_query->query_vars['post_status'] == NULL) ? ' class="current"' : '';
            $views['all'] = sprintf(__('<a href="%s"'. $class .'>All <span class="count">(%d)</span></a>', 'all'),
                admin_url('edit.php?post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'publish' ):
            $class = ($wp_query->query_vars['post_status'] == 'publish') ? ' class="current"' : '';
            $views['publish'] = sprintf(__('<a href="%s"'. $class .'>Published <span class="count">(%d)</span></a>', 'publish'),
                admin_url('edit.php?post_status=publish&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'draft' ):
            $class = ($wp_query->query_vars['post_status'] == 'draft') ? ' class="current"' : '';
            $views['draft'] = sprintf(__('<a href="%s"'. $class .'>Draft'. ((sizeof($result->posts) > 1) ? "s" : "") .' <span class="count">(%d)</span></a>', 'draft'),
                admin_url('edit.php?post_status=draft&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'pending' ):
            $class = ($wp_query->query_vars['post_status'] == 'pending') ? ' class="current"' : '';
            $views['pending'] = sprintf(__('<a href="%s"'. $class .'>Pending <span class="count">(%d)</span></a>', 'pending'),
                admin_url('edit.php?post_status=pending&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'trash' ):
            $class = ($wp_query->query_vars['post_status'] == 'trash') ? ' class="current"' : '';
            $views['trash'] = sprintf(__('<a href="%s"'. $class .'>Trash <span class="count">(%d)</span></a>', 'trash'),
                admin_url('edit.php?post_status=trash&post_type=post'),
                $result->found_posts);
        endif;
    }
    return $views;
}

//if (current_user_can('contributor') || current_user_can('author')) {