Liveblog

Contributors: automattic, nbachiyski, batmoo, johnjamesjacoby, philipjohn
Tags: liveblog
Requires at least: 3.5
Tested up to: 4.4
Stable tag: 1.5
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html

Quick and simple blogging for following fast-paced events.

Description

Your readers want your updates as quickly as possible, and we think we provide the easiest and the most flexible publishing environment to make that happen. Sometimes though, that’s just not enough.

When you’re covering a fast-paced event — the latest Apple unveiling, an F1 Grand Prix, or the Super Bowl — a full blog post for each individual update is a poor experience for your authors and your audience.

The WordPress.com VIP Liveblog Add-On was purpose-built to address these issues specifically.

Here’s what makes it special:

Post updates right from the front-end of your site (no need to use the /wp-admin dashboard)
Viewers of your Liveblog get new entries served to them instantly and automatically, without needing to refresh their browser.
Your authors can drag-and-drop photos right into the Liveblog area, without needing to navigate to separate browser tabs or windows.
There’s no need for a separate site dedicated to liveblogging: every post can be a liveblog, even existing ones.

Check out our in-depth documentation.

If you'd like to check out the code and contribute, join us on github, pull requests are more than welcome.

Installation

Upload the liveblog folder to your plugins directory (e.g. /wp-content/plugins/)
Activate the plugin through the 'Plugins' menu in WordPress
You can enable the liveblog on any post's edit page

Overview

The entry system supports #hashtags, /commands, @authors and :emoji: with an autocomplete system to help speed up the process. These extensions are filtered on save, for example a hashtag #football would be saved as <span class="liveblog-hash term-football">football</span> allowing easy styling. The container of the entry will also receive the same class term-football.

The command system has one inbuilt command:

/key: Which defines an entry to a key event, it adds the meta key to entry liveblog_key_entry. A key event can be styled using the .type-key class.

To display a key event box you can add the [liveblog_key_events] shortcode in your theme, e.g. in the sidebar, or you can use the Liveblog Key Events widget. Entries used with the key command will be inserted to both this box and the main feed. It also acts an anchor system to jump to parts of the main feed. It's not necessary to include the shortcode for the /key command to be enabled.

An example of using the key command would be an author writing the following in the New Entry box:

New iPad announced, launching next week — more info to come. /key

You can add new commands easily with a filter, the most basic command will add a class to entry, so you could do a simple /highlight which would add type-highlight to the entry container, letting you style the background color:

add_filter( 'liveblog_active_commands',  array( __CLASS__, 'add_highlight_command' ), 10 );


public static function add_highlight_command( $commands ) {
  $commands[] = highlight;
  return $commands;
}

A command can have both a filter called before the entry is saved, or an action that is called after it’s saved:

apply_filter( "liveblog_command_{$command}_before", $arg );
do_action( "liveblog_command_{$command}_after", $arg );

Customizing Key Events Shortcode

As mentioned earlier you can add the key events section by using [liveblog_key_events]. If you wish to change the title from the default Key Events then you can add a title attribute:

[liveblog_key_events title="My New Title"]

If want to remove the title, good example when placing the shortcode in a widget.

[liveblog_key_events title="false"]

A key event entry can be altered in to two ways:

Template: This is how each entry will be rendered. There are two inbuilt templates: list and timeline, or you can add your own using a filter:

add_filter( 'liveblog_key_templates', 'add_template' );

function add_template( $templates ) {
  $templates['custom'] = array( 'key-events.php', 'div', 'liveblog-key-custom-css-class' );
  return $templates;
}

There's a few things to note here:

key-events.php points to liveblog folder in the current active theme directory, in this case we our loading template file liveblog/key-events.php.
div is where we set the element type that wraps all entries, in the case where you wanted to build a list, you would set this to ul.
liveblog-key-custom-css-class is a class that will be added to the wrapper element of the entry to help with styling, in this case it would look like: <div class="liveblog-key-custom-css-class">...</div>

An example of a template file is:

<div class="<?php echo esc_attr( $css_classes ); ?>" >
	<a href="#liveblog-entry-<?php echo esc_attr( $entry_id ); ?>">
		<?php echo WPCOM_Liveblog_Entry_Key_Events::get_formatted_content( $content, $post_id ); ?>
	</a>
</div>

Format: This is how each entries content is filtered, there are three inbuilt formats:

Full - which shows content without filtering
First Sentence - which will return everything until it hits either .?!
First Linebreak - which will return everything until it hits a linebreak (Shift + Enter) or <br />.

Formats add an extra level of control to how the key events section looks. If using the timeline template with first sentence and the following is entered into the new entry box:

New iPad announced. With plan to ship next month, pre-orders starting 23rd September retailing at $499 for 16gb $599 32gb. /key

The main feed would show the full text, and the key events section would only show:

New iPad announced

You can add your own using a filter:

add_filter( 'liveblog_key_formats', 'add_format' );

function add_format( $formats ) {
  $formats['strip-tags'] = 'new_format';
  return $formats;
}

function new_format( $content ) {
  $content = strip_tags( $content );
  return $content;
}

In the example above we are adding a format Strip Tags, which removes any HTML tags from the content.

Below is the full example of adding both:

function liveblog_add_key_event_template() {

	add_filter( 'liveblog_key_templates', 'add_template' );
	add_filter( 'liveblog_key_formats',   'add_format' );

	function add_template( $templates ) {
		$templates['custom'] = array( 'key-events.php', 'div', 'liveblog-key-custom-css-class' );
		return $templates;
	}

	function add_format( $formats ) {
		$formats['strip-tags'] = 'new_format';
		return $formats;
	}

	function new_format( $content ) {
		$content = strip_tags( $content );
		return $content;
	}
}

add_action( 'init', 'liveblog_add_key_event_template' );

Selecting which template or format to use for liveblog happens in the admin panel on the edit of page of the post:

Managing Hashtags

Hashtags are manageable in the admin area. Under Posts there will be a menu for Hashtags. Please note that the slug is used, not the name.

Emjoi's

When a :emoji: is inserted into an entry it is converted into:

<img src="//s.w.org/images/core/emoji/72x72/1f44d.png" class="liveblog-emoji emoji-+1">

Extending the Admin Meta Box

If you need to extend the Admin Meta Box there are a few filters and actions to make this easier. As an example, let's add a section with a text input and a button to save. To start we need to add the fields:

Filter

add_filter( 'liveblog_admin_add_settings', array( __CLASS__, 'add_admin_options' ), 10, 2 );

public static function add_admin_options( $extra_fields, $post_id ) {
  $args = array(
    'new_label'  => __( 'My new field', 'liveblog' ),
    'new_button' => __( 'Save', 'liveblog' ),
  );

  $extra_fields[] = WPCOM_Liveblog::get_template_part( 'template.php', $args );
  return $extra_fields;
}

Template

<hr/>
<p>
  <label for="liveblog-new-input"><?php echo esc_html( $new_label ); ?></label>
  <input name="liveblog-new-input" type="text" value="" />
  <button type="button" class="button button-primary" value="liveblog-new-input-save"><?php echo esc_html( $new_button ); ?></button>
</p>

Next we catch when the user has clicked our new save button liveblog-new-input-save:

add_action( 'liveblog_admin_settings_update', array( __CLASS__, 'save_template_option' ), 10, 3 );

public static function save_template_option( $response, $post_id ) {
  if ( 'liveblog-new-input-save' == $response['state'] && ! empty( $response['liveblog-new-input-save'] ) ) {
      //handle your logic here
  }
}

Hooking into Entries

There is five useful filters to alter entries at current stages:

Before inserting into the database

add_filter( 'liveblog_before_insert_entry', array( __CLASS__, 'filter' ), 10 );

public static function filter( $entry ) {}

Before inserting updated entry into the database

add_filter( 'liveblog_before_update_entry', array( __CLASS__, 'filter' ), 10 );

public static function filter( $entry ) {}

Before we show preview (how we convert :emoji: back to <img>)

add_filter( 'liveblog_preview_update_entry', array( __CLASS__, 'filter' ), 10 );

public static function filter( $entry ) {}

Before we allow the entry to edited (how we convert <img> back to :emoji:)

add_filter( 'liveblog_before_edit_entry', array( __CLASS__, 'filter' ), 10 );

public static function filter( $content ) {}

Before the entry JSON is sent to the frontend

add_filter( 'liveblog_entry_for_json', array( __CLASS__, 'filter' ), 10, 2 );

public static function filter( $entry, $object ) {}

Altering hashtags, commands, authors and emoji

It is possible to set your own symbol and / or change the class prefix for #hashtags, /commands, @authors and :emoji:. These are handled by filters:

add_filter( 'liveblog_{type}_prefixes', array( __CLASS__, 'filter' ) );
add_filter( 'liveblog_{type}_class', array( __CLASS__, 'filter' ) );

Let’s say you decide to use ! instead of # for #hashtags, therefore you expect them to be !hashtag:

add_filter( 'liveblog_hashtags_prefixes', array( __CLASS__, 'filter' ) );

public static function filter( $prefixes ) {
  $prefixes = array( '!', '\x{21}' );
  return $prefixes;
}

Currently hashtags use the class prefix term-, you can change that to whatever you need - in this case let’s change to hashtag-:

add_filter( 'liveblog_hashtags_class', array( __CLASS__, 'filter' ) );

public static function filter( $class_prefix ) {
  $class_prefix = 'hashtag-';
  return $class_prefix;
}

WebSocket support

By default this plugin uses AJAX polling to update the list of Liveblog entries. This means that there is a delay of a few seconds between the moment a entry is created and the moment it is displayed to the users. For a close to real-time experience, it is possible to configure Liveblog to use WebSockets instead of AJAX polling. To achieve this, Liveblog uses Socket.io, Redis and socket.io-php-emitter (responsible for sending messages from PHP to the Socket.io server via Redis).

It is important to note that, since for now the Socket.io server has no way to tell if a client is an authenticated WordPress user or not and what are its capabilities, WebSockets will be used only for public Liveblog posts.

Follow the instructions below to enable WebSocket support.

Requirements

Here is a list of what needs to be installed on the server to enable WebSocket support:

Node.JS - to run the Socket.io server.
Redis - responsible for sending messages from WordPress to the Socket.io server.
Composer - to install socket.io-php-emitter and Predis (Redis client).
PHP >= 5.3

Install dependencies

Connected via SSH on the server, it is necessary to run the following commands from the Liveblog plugin directory to install WebSocket support dependencies:

composer install     # to install socket.io-php-emitter and Predis (a PHP client for Redis)
cd nodeapp
npm install     # to install socket.io and the adapter socket.io-redis

Configuration

Add the following constants to wp-config.php to configure Liveblog plugin to use WebSockets:

LIVEBLOG_USE_SOCKETIO: set this constant to true to enabled WebSocket support. Default: false.
LIVEBLOG_SOCKETIO_URL: URL used by the Socket.io client to connect to the Socket.io server. Default: YOUR_SITE_DOMAIN:3000.
LIVEBLOG_REDIS_HOST: Redis server host. Default: localhost.
LIVEBLOG_REDIS_PORT: Redis server port. Default: 6379.

Running the Socket.io server

To start the Socket.io server go to the plugin directory and run:

node nodeapp/app.js

This will start a Socket.io server on port 3000 listening to a Redis server running on localhost:6379. It is possible to use the parameters bellow to change the app default values:

--socketio-port [port]
--redis-host [host]
--redis-port [port]

For more information on the accepted parameters run:

node nodeapp/app.js --help

Making sure everything is working

To test that everything is working, after following the steps above, open a Liveblog post in two different browser windows and check that whenever a user changes the list of entries in one window, the list in the other window is refreshed in "real-time". It is also possible to use the browser developer tools to verify that there are no AJAX requests being sent every few seconds to check for changes in the list of entries. Instead the browser is receiving changes using a single WebSocket connection whenever they occur.

Important note about private Liveblog posts

When using Liveblog with WebSocket, the plugin will create a unique key for each Liveblog post (based on the post ID and its status). This key is shared with the users with permission to see the corresponding post when the page is loaded. The key is then send by the user's browser to the Socket.io server when a connection is established. Whenever there is a new Liveblog entry (or a Liveblog entry is updated or deleted), the Socket.io server will send a message only to the clients that provided the right key. This system is enough to prevent someone without permission to see the post from receiving Liveblog entries emitted by the Socket.io server but it has an important limitation. Once a user with permission receives the post key, if he saves it somewhere, he will be able to receive messages from the Socket.io server for that particular post even if for some reason he loses access to the post (for example if the user is removed from WordPress).

If you are using private Liveblog posts to share sensitive data and it is important that, once a user loses access to the post, he is not able to receive messages emitted by the Socket.io server anymore, consider using the 'liveblog_socketio_post_key' filter to implement your own criteria to generate the post key. For example, you could generate a random post key for each post that is saved as a post meta and that can be manually invalidated by an editor whenever necessary.

Tips for debugging

If for some reason the plugin is not able to use WebSockets to refresh the list of entries, below is a list of tips that might help you debug where is the problem:

Use your browser developer tools network tab to check if a WebSocket connection was established or check the browser console for errors when trying to establish it.
Check if the Node.js app that starts the Socket.io server is running. The app won't start or will stop running if unable to connect to the Redis server.
The plugin will fallback to AJAX polling if unable to connect to the Redis server.
It is possible to see all the messages received by the Redis server using the command redis-cli MONITOR
To see Socket.io server debug messages start the Node.js app with the command DEBUG=socket.io* node nodeapp/app.js

Screenshots

Changelog

1.5

New "Key Events" feature
New "Lazyloading" feature
Improved escaping

People who helped make this happen: Jason Agnew, Josh Betz, Sarah Blackstock, Stephane Boisvert, Ian Dunn, Scott Evans, Thorsten Frommen, Mark Goodyear, Chris Hardie, Philip John, Paul Kevan, Connor Parks

1.4.1

Bump tested tag to 4.2.2.
Added Composer support!

1.4

Rich-text editing!
Archived liveblogs now display in chronological order (live ones show reverse chron)
New and udpated translations
Bump to fix SVN sync issues (thanks @kevinlisota)

1.3.1

Fixed a bug where liveblog would show up in secondary loops

1.3

The liveblog plugin now requires WordPress 3.5.

New functionality:

Liveblog archiving
Shows automatically new entries, with a slick notification bar if we have scrolled out of view. With the help of @borkweb and @zbtirrell
Front-end editing
Pasting an image URL embeds the image

Translations:

German by @cfoellmann
Spanish by @elarequi

Also a lot of internal improvements and bug fixes. See the full list of closed issues.

1.2