Configuration and Options System

Relevant source files

• includes/MslsAdmin.php
• includes/MslsBlog.php
• includes/MslsBlogCollection.php
• includes/MslsOptions.php
• includes/MslsOptionsPost.php
• includes/MslsOptionsQuery.php
• includes/MslsOptionsTax.php
• includes/MslsOptionsTaxTerm.php
• includes/MslsOutput.php
• includes/MslsPlugin.php

Purpose and Scope

The Configuration and Options System manages all plugin settings and translation relationship data across the WordPress multisite network. This system handles two distinct categories of data:

1. Global plugin settings - user preferences like display modes, flags, and behavior toggles stored in wp_options
2. Translation relationship data - mappings between posts, taxonomies, and archives across blogs stored in wp_postmeta, wp_termmeta, and object cache

For information about how translation links are established and maintained, see Translation Linking System. For details about admin UI components, see Settings and Configuration Pages.

Sources: includes/MslsOptions.php1-432 includes/MslsAdmin.php1-485

Options Class Hierarchy

The options system uses an inheritance hierarchy where MslsOptions serves as the base class with specialized subclasses for different content contexts:

Class Responsibilities:

Class	Purpose	Storage Location
MslsOptions	Base settings class for global plugin configuration	wp_options table with key msls
MslsOptionsPost	Translation links for posts/pages	wp_postmeta with key msls_{post_id}
MslsOptionsTax	Translation links for taxonomies	wp_termmeta with key msls_term_{term_id}
MslsOptionsTaxTerm	Specialized handling for post tags	wp_termmeta with tag base rewriting
MslsOptionsTaxTermCategory	Specialized handling for categories	wp_termmeta with category base rewriting
MslsOptionsQuery	Archive query options (dates, authors, post types)	WordPress object cache

Sources: includes/MslsOptions.php29-432 includes/MslsOptionsPost.php10-56 includes/MslsOptionsTax.php10-132 includes/MslsOptionsQuery.php10-85

Storage and Persistence Mechanism

Options are stored using WordPress's native storage APIs with different mechanisms based on content type:

Storage Implementation Details:

The get_option_name() method constructs unique keys using prefixes and separators:

• MslsOptions: msls (no separator, no args)
• MslsOptionsPost: msls_{post_id} (separator: _)
• MslsOptionsTax: msls_term_{term_id} (separator: _term_)

The save() method includes/MslsOptions.php170-178 implements atomic updates:

1. Delete existing option via delete()
2. Validate and set new values via set()
3. Add new option via add_option() with autoload flag

The autoload property controls WordPress option loading behavior:

• true for MslsOptions (loaded on every request)
• false for MslsOptionsPost and MslsOptionsTax (loaded on-demand)

Sources: includes/MslsOptions.php83-107 includes/MslsOptions.php139-147 includes/MslsOptions.php170-185

Factory Pattern and Context Detection

The MslsOptions::create() factory method includes/MslsOptions.php83-107 determines the appropriate options class based on request context:

Context Detection Methods:

Method	Condition	Returns
is_main_page()	is_front_page() || is_search() || is_404()	MslsOptions
is_tax_page()	is_category() || is_tag() || is_tax()	MslsOptionsTax::create()
is_query_page()	is_date() || is_author() || is_post_type_archive()	MslsOptionsQuery::create()

Sources: includes/MslsOptions.php83-107 includes/MslsOptions.php114-134 includes/MslsOptionsTax.php24-40 includes/MslsOptionsQuery.php44-64

Settings Administration Interface

MslsAdmin includes/MslsAdmin.php27-484 provides the administrative UI for configuring plugin settings. It registers settings sections, fields, and handles validation.

Settings Section Map:

Section ID	Title	Method	Fields
language_section	Language Settings	language_section()	blog_language
main_section	Main Settings	main_section()	display, admin_display, sort_by_description, output_current_blog, only_with_translation, description, before_output, after_output, before_item, after_item, content_filter, content_priority
advanced_section	Advanced Settings	advanced_section()	activate_autocomplete, image_url, reference_user, exclude_current_blog, activate_content_import
rewrites_section	Rewrites Settings	rewrites_section()	rewrite_{post_type} (dynamic based on registered post types)

Magic Method Pattern:

The __call() method includes/MslsAdmin.php96-130 dynamically renders form fields based on method name:

• Checkbox fields: defined in $checkboxes array at includes/MslsAdmin.php103-117
• Rewrite fields: detected by prefix rewrite_ at includes/MslsAdmin.php98-100
• Text fields: fallback for all other methods at includes/MslsAdmin.php126-129

Sources: includes/MslsAdmin.php43-68 includes/MslsAdmin.php213-239 includes/MslsAdmin.php248-316 includes/MslsAdmin.php450-466

Configuration Properties Reference

The MslsOptions class exposes configuration properties via magic methods (__get/__set):

Display and Output Properties

Property	Type	Purpose	Default
display	int	Link display mode (flag/label/flag+label)	0
admin_display	string	Admin icon type (flag or label)	flag
before_output	string	HTML before language switcher list	''
after_output	string	HTML after language switcher list	''
before_item	string	HTML before each language link	''
after_item	string	HTML after each language link	''
description	string	Custom blog description	''
image_url	string	Custom flag images URL	''

Behavior Toggles

Property	Type	Purpose
activate_autocomplete	bool	Enable AJAX autocomplete in meta boxes
activate_content_import	bool	Enable content import functionality
sort_by_description	bool	Sort languages by description instead of code
exclude_current_blog	bool	Exclude this blog from output
only_with_translation	bool	Show only links with translations
output_current_blog	bool	Display link to current language
content_filter	bool	Add translation hints to content

Advanced Properties

Property	Type	Purpose
reference_user	int	User ID whose blogs are used for collection
content_priority	int	Priority for content filter hook (1-100)
with_front	bool	Use permalink front base in URLs

Language Detection:

The get_available_languages() method includes/MslsOptions.php363-387 returns available WordPress language packs:

1. Starts with en_US as default
2. Calls get_available_languages() WordPress function
3. Formats each language code via format_code_lang()
4. Applies msls_options_get_available_languages filter

Sources: includes/MslsOptions.php29-73 includes/MslsOptions.php363-387

Permalink and URL Generation

Each options subclass implements get_postlink() and get_current_link() methods to generate URLs for translation links:

URL Processing Pipeline:

1. Content-specific permalink generation: Each subclass retrieves the appropriate WordPress permalink
2. Deprecated filter: check_url filter applied at includes/MslsOptionsPost.php43 includes/MslsOptionsTax.php94
3. Standard filter: msls_get_postlink hook applied for customization
4. Final filter: msls_options_get_permalink for last-minute modifications
5. Fallback: Returns home_url('/') if URL is empty

Blog Slug Handling:

The check_for_blog_slug() method includes/MslsOptions.php397-422 addresses subdomain installs with permalinks:

• Removes home URL from path
• Detects permalink structure from main site
• Strips/adds front base depending on with_front setting
• Ensures URLs work correctly across blog contexts

Sources: includes/MslsOptions.php217-233 includes/MslsOptionsPost.php26-46 includes/MslsOptionsTax.php87-97 includes/MslsOptionsQuery.php73-84

Rewrite Rule Handling

Taxonomy and post type options handle custom rewrite bases to ensure URLs remain consistent across blogs:

Rewrite Handling Flow:

1. Taxonomy Detection: get_tax_query() retrieves the queried taxonomy name includes/MslsOptionsTax.php68-78
2. With-Front Detection: handle_rewrite() checks if taxonomy uses front base includes/MslsOptionsTax.php55-61
3. Base Correction: For tags/categories, check_base() compares defined vs. configured bases includes/MslsOptionsTaxTerm.php37-53
4. URL Adjustment: Replaces base in URL if they differ

Special Cases:

• WooCommerce: Special handling for WooCommerce product taxonomies at includes/MslsOptionsTax.php71-72
• Post Tags: MslsOptionsTaxTerm with tag_base option includes/MslsOptionsTaxTerm.php12-13
• Categories: MslsOptionsTaxTermCategory with category_base option

Sources: includes/MslsOptionsTax.php55-78 includes/MslsOptionsTaxTerm.php23-73

Integration with Plugin Lifecycle

The options system integrates with plugin initialization and cleanup:

Initialization Sequence:

1. MslsPlugin::init() includes/MslsPlugin.php34-100 checks for multisite
2. If admin context, MslsAdmin::init() includes/MslsAdmin.php43-68 registers settings page
3. Registry pattern prevents duplicate initialization
4. Settings page added via add_options_page() with capability check

Cleanup Process:

The cleanup() method includes/MslsPlugin.php239-246 removes all plugin data:

1. Deletes main msls option from wp_options
2. Executes CleanupOptionsQuery to remove all post/term meta
3. Repeats for all blogs in network during uninstall includes/MslsPlugin.php211-229

Sources: includes/MslsPlugin.php34-100 includes/MslsAdmin.php43-68 includes/MslsPlugin.php211-246

Filter and Action Hooks

The options system provides several extension points:

Configuration Filters

Filter Hook	Location	Purpose
msls_admin_caps	includes/MslsAdmin.php57	Override required capability for settings access
msls_admin_validate	includes/MslsAdmin.php458	Filter settings before validation
msls_options_get_available_languages	includes/MslsOptions.php380-383	Customize available language list
msls_options_get_flag_url	includes/MslsOptions.php341	Override flag images directory
msls_options_get_flag_icon	includes/MslsOptions.php353	Customize flag icon filename
msls_options_get_permalink	includes/MslsOptions.php226-230	Filter final permalink output

Settings Registration Actions

Action Hook	Location	Purpose
MSLS_REGISTER_ACTION	includes/MslsAdmin.php238	Add custom settings sections (value: msls_admin_register)
MSLS_ACTION_PREFIX . {section}	includes/MslsAdmin.php337	Add fields to specific section (e.g., msls_admin_language_section)

Example: Adding Custom Settings Section

Sources: includes/MslsAdmin.php29-31 includes/MslsAdmin.php213-239 includes/MslsOptions.php217-233