Field value is wiped on post save if Field attributes are disabled => disabled

[kynetiv]

I have a field with the attributes set to readonly and disabled:

$allow_ad_sync->add_field( array(
                'name' => __( 'Last Modified', 'cmb2' ),
                'desc' => __( 'Time last modified in LDAP', 'cmb2' ),
                'id'   => $prefix . 'last_modified',
                'type' => 'text_date_timestamp',
                'date_format' => 'm-d-Y @ h:i:s',
                'on_front' => false, // Optionally designate a field to wp-admin only
                'show_on_cb' => array( $this, 'upd_cbm2_is_user_admin' ), // function should return a bool value,
                'attributes'  => array(
                    'readonly' => 'readonly',
                    'disabled' => 'disabled',
                ),
            ) );

I populate the field value through a separate script and just wish to display it to users without giving them the ability to update it ( readonly and disabled ).

This issue here is that because it isn't passed along in the $_POST data ( I believe because it is marked as disabled in the DOM ) the value is set to null in CMB2_Field.php on line 429:
https://github.com/WebDevStudios/CMB2/blob/master/includes/CMB2_Field.php#L429

/**
     * Process $_POST data to save this field's value
     * @since  2.0.3
     * @param  array $data_to_save $_POST data to check
     * @return bool                Result of save
     */
    public function save_field_from_data( $data_to_save ) {

        $meta_value = isset( $data_to_save[ $this->id( true ) ] )
            ? $data_to_save[ $this->id( true ) ]
            : null;

        return $this->save_field( $meta_value );
    }

Setting it to null is then set as the value and wipes my field's value. Instead there probably should be a check for disabled fields and not apply any update. The benefit of adding a conditional here would disallow tampering with the DOM (although there are probably other checks for that already).

As a workaround I've added a hook to the override filter here:
https://github.com/WebDevStudios/CMB2/blob/master/includes/CMB2_Field.php#L290
for my specific field_id on the filter (I may do one more generic for disabled fields in general, but right now I only have the one field):

add_filter( 'cmb2_override_{_my_prefix_and_field_id}_meta_remove', array($this, 'upd_dont_remove_disabled_field'), 10, 4 );

    public function upd_dont_remove_disabled_field($override, $args, $field_args, $field_object) {
        $override = true;
        return $override;
    }

This override filter above fixes the issue but disabled fields probably shouldn't be updated at all or require a filter like this.

[jtsternberg]

Some good thoughts here. As an alternative, you can set the 'default'attribute to the value of the field (saved elsewhere/different meta key). Then that value will always display even though it doesn't get saved. the 'default' field attribute can also take a callback, so you can fetch that value at the last minute.

[modemlooper]

I'm having this issue on repeatable group fields. I have a group of fields and if they choose a specific option from the select js disables other fields. The fields have default values but they get wiped out on save.

I think i might have to resort to hidden fields so the value can't be changed

[jtsternberg]

readonly and disabled attributes are used for specific and varied purposes, and I'm not sure there is a good "standard" solution that should be applied here, but I am open to ideas.

@modemlooper hidden fields could work, but you could also possibly remove the disabled attribute via JS when saving. That may do it. You could also use a filter like @kynetiv.

Unless you guys have a specific idea as to how this be handled by default (different than it is), I think we should close this issue.

[jamesgol]

I submitted that PR last year that covers the situation.

[jtsternberg]

If anyone is up for submitting a PR to introduce a field property 'save_field', that could be a decent solution. (see more)

[jtsternberg]

#674