Added ability to change login errors

Author: dmhendricks

.gitignore

@@ -0,0 +1,3 @@
+.DS_Store
+*.bak
+*.log

CHANGELOG.md

@@ -0,0 +1,16 @@
+# Changelog
+
+### master
+
+- Fixed: Firing sequence of `common_toolkit_loaded` hook
+- Added: `ctk_environment` filter
+- Added: Ability to change login errors
+- Added: Ability to cache JSON config file
+- Added: Ability to disable WordPress core, plugin and/or theme updates
+- Added: Ability to modify or disable WordPress heartbeat
+- Added: Ability to disable WordPress search
+- Added: Ability to define custom environment constant
+
+### 0.8.0 - January 27, 2019
+
+- Initial release

README.md

@@ -5,43 +5,127 @@
 
 # WordPress Common Toolkit MU Plugin
 
-A simple [MU plugin](https://codex.wordpress.org/Must_Use_Plugins) for WordPress that adds functionality that I use on web site projects.
+A simple [MU plugin](https://codex.wordpress.org/Must_Use_Plugins) for WordPress that adds functionality that I use on web site projects, including a [configuration registry](#getting-configuration-values).
+
+- [Installation](#installation)
+- [Configuration](#configuration)
+- [Features](#features)
+- [Environment Filter](#environment-filter)
+- [Action Hook](#action-hook)
+- [Shortcodes](#shortcodes)
 
 ## Installation
 
 Simply copy the `common-toolkit.php` file to your `wp-content/mu-plugins` directory (create one if it does not exist).
 
-## Requirements
+### Requirements
 
-- PHP 7.0 or higher
+- **PHP 5.4+** (via JSON config file) and **PHP 7.x** (via array _or_ JSON file)
 - WordPress 4.7 or higher
 
 ## Configuration
 
-| **Variable**           | **Description**                                                                                                          | **Type**    | **Default**   |
-|------------------------|--------------------------------------------------------------------------------------------------------------------------|-------------|---------------|
-| `environment`          | Environment of current instance (ex: 'production', 'development', 'staging')                                             | string      | "production"  |
-| `disable_emojis`       | Remove support for emojis                                                                                                | bool        | false         |
-| `admin_bar_color`      | Change admin bar color in current environment                                                                            | string      | _null_        |
-| `script_attributes`    | Enable support for [additional attributes](#add-attributes-to-enqueued-scripts) to script tags via wp_enqueue_script()   | bool        | flase         |
-| `shortcodes`           | Enable custom [shortcodes](#shortcodes) created by this class                                                            | bool        | false         |
-| `disable_xmlrpc`       | Disable XML-RPC                                                                                                          | bool        | false         |
-| `meta_generator`       | Enable or change meta generator tags in page head and RSS feeds                                                          | bool/string | true          |
-| `windows_live_writer`  | Enable [Windows Live Writer](https://is.gd/Q6KjEQ) support                                                               | bool        | true          |
-| `feed_links`           | Include RSS feed links in page head                                                                                      | bool        | true          |
+All variables are optional.
+
+| **Variable**              | **Description**                                                                                                          | **Type**          | **Default**   |
+|---------------------------|--------------------------------------------------------------------------------------------------------------------------|-------------------|---------------|
+| `environment`             | Environment of current instance (ex: 'production', 'development', 'staging')                                             | string            | "production"  |
+| `environment_constant`    | Constant used to determine environment, environmental variable name for `getenv()`.                                      | string            | "WP_ENV"      |
+| `environment_production`  | The label used to match if production environment.                                                                       | string            | "production"  |
+| `admin_bar_color`         | Change admin bar color in current environment                                                                            | string            | _null_        |
+| `disable_emojis`          | Remove support for emojis                                                                                                | bool              | false         |
+| `disable_search`          | Disable WordPress site search                                                                                            | bool              | false         |
+| `disable_updates`         | Disable WordPress core, plugin and/or theme updates. Values: 'core', 'plugin', 'theme'; `true` for all                   | bool/string/array | false         |
+| `disable_xmlrpc`          | Disable XML-RPC                                                                                                          | bool              | false         |
+| `feed_links`              | Include RSS feed links in page head                                                                                      | bool              | true          |
+| `heartbeat`               | Modify or disable the WordPress heartbeat. Set to integer to change, `false` to disable                                  | bool/int          | null          |
+| `hide_login_errors`       | Replaces login errors with generic "Login failed" text rather than specific reason                                       | bool/string       | null          |
+| `meta_generator`          | Enable or change meta generator tags in page head and RSS feeds                                                          | bool/string       | false         |
+| `script_attributes`       | Enable support for [additional attributes](#add-attributes-to-enqueued-scripts) to script tags via wp_enqueue_script()   | bool              | flase         |
+| `shortcodes`              | Enable custom [shortcodes](#shortcodes) created by this class                                                            | bool              | false         |
+| `windows_live_writer`     | Enable [Windows Live Writer](https://is.gd/Q6KjEQ) support                                                               | bool              | true          |
 
 ### Example
 
-Add to your `wp-config.php`:
+#### Via Configuration File (PHP 5.6 or higher)
+
+This is the preferred method if you wish to avoid having a complex array in your `wp-config.php`:
+
+```php
+// Load configuration from a file in webroot. 
+define( 'CTK_CONFIG', 'sample-config.json' );
+
+// Load configuration from a file off of the parent directory of webroot
+define( 'CTK_CONFIG', '../conf/sample-config.json' );
+```
+
+See [sample-config.json](https://github.com/dmhendricks/wordpress-mu-common-toolkit/blob/master/sample-config.json) for example.
+
+#### Via Array (PHP 7 or higher)
+
+Rather than using a JSON file for configuration, you can set `CTK_CONFIG` to an array of valyes in `wp-config.php`:
 
 ```php
 define( 'CTK_CONFIG', [ 'disable_emojis' => true, 'admin_bar_color' => '#336699', 'script_attributes' => true, 'meta_generator' => 'Atari 2600' ] );
 ```
 
+### Caching JSON Config File
+
+If your WordPress Instance has caching enabled, you can configure this plugin to cache the contents of your configuration JSON file with a constant in `wp-config.php`:
+
+```php
+define( 'CTK_CACHE_EXPIRE', 120 ); // In seconds
+```
+
+### Getting Configuration Values
+
+You can use the `ctk_config` filter to retrieve values from the config registry (including custom). Using [sample-config.json](https://github.com/dmhendricks/wordpress-mu-common-toolkit/blob/master/sample-config.json) as an example:
+
+```php
+// Get meta generator value
+$meta_generator = apply_filter( 'ctk_config', 'common_toolkit/meta_generator' );
+
+// Get single custom variable
+$ny_var = apply_filter( 'ctk_config', 'my_custom_variable' );
+
+// Get an array of classic books
+$classic_books = apply_filter( 'ctk_config', 'nested_example/books/classics' );
+
+// Get entire config registry as associative array
+$config = apply_filter( 'ctk_config', null );
+```
+
+You can add any variable you want to make available to your site's themes and plugins.
+
 ## Features
 
 ### WordPress Environment
 
+You can set your instance environment using the following methods (in order of precedence; defaults to "production" if not set using any of the following methods):
+
+#### 1. Define a Constant in `wp-config.php`
+
+```php
+define( 'WP_ENV', 'staging' );
+```
+
+If you wish to use a different constant name, you can set the `environment_constant` in the config:
+
+```php
+define( 'MY_ENVIRONMENT', 'development' );
+define( 'CTK_CONFIG', [ 'environment_constant' => 'MY_ENVIRONMENT' ] );
+```
+
+This will also change the name of the environmental variable used to retrieve the environment:
+
+```php
+echo getenv( 'MY_ENVIRONMENT' ); // Result: development
+// ...or:
+echo apply_filters( 'ctk_environment', null ); // Result: development
+```
+
+#### 2. Define `environment` Variable in Config
+
 Setting:
 
 ```php
@@ -52,6 +136,8 @@ Getting:
 
 ```php
 echo getenv( 'WP_ENV' ); // Result: staging
+// ...or:
+echo apply_filters( 'ctk_environment', null ); // Result: staging
 ```
 
 If not defined, "production" is returned.
@@ -92,6 +178,77 @@ $parse_uri['fragment'] = 'newhash';
 $uri = \MU_Plugins\CommonToolkit::build_url( $parse_uri );
 ```
 
+### Disable WordPress Core, Plugin and/or Theme Updates
+
+You can disable any of the update notifications or specific. It accepts string, boolean or an array of values. Examples:
+
+```php
+// Disable all update notifications
+define( 'CTK_CONFIG', [ 'disable_updates' => true ] ); // boolean
+
+// Disable WordPress core and theme updates only (not plugins)
+define( 'CTK_CONFIG', [ 'disable_updates' => [ 'core', 'theme' ] ] ); // array
+
+// Disable only plugin updates updates
+define( 'CTK_CONFIG', [ 'disable_updates' => 'plugin' ] ); // string
+```
+
+## Environment Filter
+
+You can alternately retrieve the current environment using the `ctk_environment` filter:
+
+```php
+echo apply_filters( 'ctk_environment', null ); // 'production', 'staging', etc
+```
+
+You can also pass `is_production` to determine if we're currently in production more. It compares the value of your environment (defined above) with the value of `common_toolkit/environment_production` (which defaults to "production"). In this way, you can set your production label/string value to whatever you like.
+
+Determining if in production mode using **defaults**:
+
+```php
+if( apply_filters( 'ctk_environment', 'is_production' ) ) {
+   // Do something intended only for production
+} else {
+   // Do something else
+}
+```
+
+As noted above, you can change the string comparison of what is considered production in config. For example, if you wanted to use "live" instead of "production":
+
+```php
+define( 'CTK_CONFIG', [ 'environment_production' => 'live' ] );
+
+// Result: true
+define( 'WP_ENV', 'live' ); // wp-config.php
+var_dump( apply_filters( 'ctk_environment', 'is_production' ) );
+
+// Result: false
+define( 'WP_ENV', 'staging' ); // wp-config.php
+var_dump( apply_filters( 'ctk_environment', 'is_production' ) );
+```
+
+This special filter value is provided solely for convenience. You may, of course, do a manual comparison:
+
+```php
+if( getenv( 'WP_ENV' ) == 'production' ) { // Replace variable with value of `environment_constant`, if set
+   // Do something intended only for production
+} else {
+   // Do something else
+}
+```
+
+
+## Action Hook
+
+If you want to perform some logic only if this script is loaded, you can use the `common_toolkit_loaded` action hook (which executes during the [init](https://codex.wordpress.org/Plugin_API/Action_Reference#Actions_Run_During_a_Typical_Request) phase).
+
+```php
+add_action( 'common_toolkit_loaded', function() {
+	// Do something if common toolkit is loaded ...
+	var_dump( apply_filters( 'ctk_config', null ) );
+});
+```
+
 ## Shortcodes
 
 ### `[get_datetime]`
@@ -111,23 +268,4 @@ Current date/time: [get_datetime]
 
 See PHP's [`date()`](https://php.net/date) function for formatting options.
 
-## Future Plans
-
-- Add support for PHP 5.6
-- Add support for external config and`.env` files
-- Detect [Classic Editor](https://wordpress.org/plugins/classic-editor/)/[ClassicPress](https://www.classicpress.net/)
-- Add ability to change favicons by environment
-- Custom WP Admin footer
-- Add function to test if WP Object Cache is enabled
-- Add rewrite for custom image/script URLs/CDN support
-- Hide login errors
-- Disable update notifications: core, plugins, themes or all; Option to remove for all but admins
-- Change excerpt length
-- Ability to add class instance to $GLOBALS
-- Remove `?ver=` from some/all scripts
-- Disable JSON REST API
-- Enable TinyMCE lower toolbar
-- Completely disable comments
-- Inject standard Google Analytics script
-
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