Show global Message in User Profiles with admin only Input field in Wordpress Backend

Question

I try to display a piece of text (without plugin) for example "Quote of the day: Some text" on all user profile pages (.../wp-admin/profile.php).

This Text should managable/editable from the Profile of the ADMIN. In the Admins Profile Page should be a Text Input field where i can change the Text and save.

Since yesterday i was not able to find any hint to achive this. I found a lot of tutorials to create custom User Field for the profile Page - but nothing like i need.

So far i was able to create a text input field where i can save the text (input) in the database and display it only in the admins profile page with:

function add_qoute_of_the_day_backend( $user ) { 
// Visible only for admins
if( current_user_can( 'administrator' ) ) { 
?>
<div class="visible-only-for-admin">
    <h3>Quote of the Day Input Field</h3>
    <table class="form-table" >
        <tr>
            <th><label for="qoute_of_the_day">Qoute of the Day</label></th>
            <td><input type="text" name="qoute_of_the_day" value="<?php echo esc_attr(get_the_author_meta( 'qoute_of_the_day', $user->ID )); ?>" class="regular-text" /></td>
        </tr>
    </table>
</div>
<?php } ?>
<?php }
add_action( 'show_user_profile', 'add_qoute_of_the_day_backend', 10 );
add_action( 'edit_user_profile', 'add_qoute_of_the_day_backend', 10 );

function save_qoute_of_the_day_backend( $user_id ) {
    if ( !current_user_can( 'edit_user', $user_id ) )
    return false;       
    update_user_meta( $user_id,'qoute_of_the_day', sanitize_text_field ( $_POST['qoute_of_the_day'] ) );
}
add_action( 'personal_options_update', 'save_qoute_of_the_day_backend' );
add_action( 'edit_user_profile_update', 'save_qoute_of_the_day_backend' );

The code above works, but how can i display the input of the admin, in Text Form (just: "Quote of the day: Some Text") in all other user profiles? Maybe any way to create a simple input field just for the admin Role and display the input in all profiles?

Visual - what im trying to achive:

INPUT FIELD in the profile page of the admin:

DISPLAY Text in all other user profiles:

Any help would be greatly appreciated

Answer 1

You just need to move the capability check "inwards":

function wpse_230369_quote_of_the_day( $user ) { 
    $quote = esc_attr( get_option( 'quote_of_the_day' ) );
    ?>

<div class="visible-only-for-admin">
    <h3>Quote of the Day Input Field</h3>
    <table class="form-table" >
        <tr>
            <th><label for="quote_of_the_day">Quote of the Day</label></th>
            <td>
                <?php if ( current_user_can( 'administrator' ) ) : ?>

                    <input type="text" name="quote_of_the_day" value="<?php echo $quote ?>" class="regular-text" />

                <?php else : ?>

                    <?php echo $quote ?>

                <?php endif ?>
            </td>
        </tr>
    </table>
</div>

<?php
}

add_action( 'show_user_profile', 'wpse_230369_quote_of_the_day', 10 );
add_action( 'edit_user_profile', 'wpse_230369_quote_of_the_day', 10 );

function wpse_230369_save_quote_of_the_day( $user_id ) {
    if ( isset( $_POST['quote_of_the_day'] ) && current_user_can( 'administrator' ) )
        update_option( 'quote_of_the_day', sanitize_text_field( wp_unslash( $_POST['quote_of_the_day'] ) ) );
}

add_action( 'edit_user_profile_update', 'wpse_230369_save_quote_of_the_day' );
add_action( 'personal_options_update',  'wpse_230369_save_quote_of_the_day' );