Example of a dynamic plugin setting

config.tmpl

<mtapp:setting
    id="dynamic_setting"
    label="Dynamic Setting">
    <input type="text" name="dynamic_setting" value="<mt:var name="dynamic_setting">" />
</mtapp:setting>

<mt:loop name="custom_setting_loop">
  <mtapp:setting
     id="$setting_name"
     label="$setting_name">
    <input type="text" name="<mt:var name="setting_name">" value="<mt:var name="setting_value">" />
  </mtapp:setting>
</mt:loop>

config.yaml

name: Plugin Name

settings:
    dynamic_setting:
        scope: blog
        default: 0
    settings_hash:
        scope: blog

init: sub { my $p = shift; require PluginName::Plugin; bless $p, 'PluginName::Plugin', $p;  }

config_template: config.tmpl

Plugin.pm

package PluginName::Plugin;

use strict;
use warnings;

use base qw( MT::Plugin );

use MT::Util qw(dirify);

sub load_config {
    my $plugin = shift;

    $plugin->SUPER::load_config(@_);
    my ( $param, $scope ) = @_;

    if ( $scope =~ /^blog:(\d+)$/ ) {
        my $blog_id = $1;

        # tweak $param as needed for values
        # to pass to the config template

        # for example, set dynamic_setting to the current time
        $param->{dynamic_setting} = time;

        require MT::Blog;
        my $blog         = MT::Blog->load($blog_id);
        my $setting_name = dirify( $blog->name );
        $param->{custom_setting_loop} = [
            {   setting_name => $setting_name,
                setting_value =>
                    $plugin->get_config_value( $setting_name, $scope ) || ${
                    $plugin->get_config_value( 'settings_hash', $scope ) || {}
                    }{$setting_name}
            }
        ];
    }
}

sub save_config {
    my $plugin = shift;
    my ( $param, $scope ) = @_;

    if ( $scope =~ /^blog:(\d+)$/ ) {
        my $blog_id = $1;
        require MT::Blog;
        my $blog          = MT::Blog->load($blog_id);
        my $setting_name  = dirify( $blog->name );
        my $setting_value = $param->{$setting_name};

        $param->{settings_hash} = { $setting_name => $setting_value };
    }

    $plugin->SUPER::save_config(@_);

    if ( $scope =~ /^blog:(\d+)$/ ) {
        my $blog_id = $1;

        require MT::Blog;
        my $blog         = MT::Blog->load($blog_id);
        my $setting_name = dirify( $blog->name );

        my $setting_value = $param->{$setting_name};
        $plugin->set_config_value( $setting_name, $setting_value, $scope );
    }
}

Thanks for this example :-)

Here the setting "dynamic_setting" is declared beforehand in the YAML file. Is it possible to have no such declaration, and have the init procedure (or is that load_config?) declare dynamically a list of settings instead? That's what I meant by dynamic, not the value of the setting, but the list of settings (keys).

In other words, can I use $plugin->set_config_value($key, $value); at will here with keys that I create (from the list of existing Custom Fields keys in this specific case)? Something like:

• at plugin init or load_config:
• get the list of CF keys for this blog
• get existing config values for this blog
• update the list of config keys to match the list of CF keys (add new ones when a CF has been added, remove those of CFs that have been deleted since the last launch)
• at plugin normal run:
• expose those settings through the plugin settings page via mtapp:setting blocks for editing values
• use those values to perform certain actions or control on various edit screens (think of a length limit for text fields for example)