PHP TOC Generator

Geneates Table of Contents from H1...H6 Tags in HTML Content

This package provides a simple, framework-agnostic library to build a Table-of-Contents from HTML markup. It does so by parsing H1...H6 tags. It can also automatically add appropriate "id" anchor links to header tags.

Features:

• Generates menu iterator or HTML <li*gt; tags
• Can add anchor IDs to H1...H6 where they do not already exist
• Specify which H1...H6 heading tags to include in the TOC
• Includes Twig Extension for generating TOC lists and compatible markup directly from templates
• Uses the flexible KnpMenu Library to generate menus
• PSR-0 thru PSR-2 Compliant
• Composer-compatible
• Unit-tested

In the spirit of KISS philosophy, this library makes a few assumptions:

1. The hierarchy of your content is defined solely by the header (H1...H6) tags. All other tags are ignored.
2. The link titles in the Table of Contents should match either the title attribute of the header tag, or if there is no title, the plaintext body of the header tag.

Installation Options

Install via Composer by including the following in your composer.json file:

{
    "require": {
        "caseyamcl/toc": "~1.0",
    }
}

Or, drop the src folder into your application and use a PSR-4 autoloader to include the files.

Usage

This contains two basic classes:

1. MarkupFixer: Adds id anchor attributes to any H1...H6 tags that do not already have any.
2. TocGenerator: Generates HTML (or an associative array) of anchor links that can be rendered in your template.

Basic Example:

$myHtmlContent = <<<END
    <h1>This is a header tag with no anchor id</h1>
    <p>Lorum ipsum doler sit amet</p>
    <h2 id='foo'>This is a header tag with an anchor id</h2>
    <p>Stuff here</p>
    <h3 id='bar'>This is a header tag with an anchor id</h3>
END;

$markupFixer  = new TOC\MarkupFixer();
$tocGenerator = new TOC\TocGenerator();

// This ensures that all header tags have `id` attributes so they can be used as anchors
$htmlOut  = "<div class='content'>" . $markupFixer->fix($myHtmlContent) . "</div>";

// This generates the Table of Contents List
$htmlOut .= "<div class='toc'><ul>" . $tocGenerator->getHtmlMenu($myHtmlContent) . "</ul></div>";

echo $htmlOut;

Twig Integration

This library includes a Twig extension that enables you to load TOC lists and add anchors to markup from your Twig templates.

Specifically, the extension adds a Twig function for generating Table of Contents HTML:

{# Generates HTML markup for given htmlContent #}
{# The second two parameters are optional (defaults are 1, 6) #}
<ul>{{ toc(htmlContent, '1', '3') }}</ul>

It also adds one function and one filter for ensuring that your content includes anchors for all HTML tags:

{# Adds anchor links (id tags) for given htmlContent #}
{# The second two parameters are optional (defaults are 1, 6) #}
{{ add_anchors(htmlContent, '1', '2')

{# You can also use it as a filter #}
<div class='my_content'>
    {{ htmlContent | add_anchors('h1', 'h3') }}
</div>

You may have content in hard-coded in your Twig Template that you want to TOC-ize. An easy way to do this is to make sure the content is surrounded by {% block %}...{% endblock %} tags, and then just pass in that content to the toc functions>

For example:

{% extends 'base.html.twig' %}
{% block page_content %}
<div class='page_sidebar'>
   {{ toc(add_anchors(block('my_writeup'), 'h1', 'h2'), 'h1', 'h2') }}
</div>

<div class='page_content'>
   {{ add_anchors(block('my_writeup'), 'h1', 'h2') }}
</div>
{% endblock %}

{% block my_writeup %}
<h1>Hi There</h1>
<p>Lorum ipsum baz biz etecetra</p>
<h2>This is some content</h2>
<p>More content here.  Blah blah</p>
{% endblock %}

In order to enable this functionality, you must register the TocTwigExtension with your Twig environment:

$myTwig = new \Twig_Environment();
$myTwig->addExtension(new TocTwigExtension());

Customizing Menu Output

The TocGenerator class outputs HTML by default, but you can customize the rendering of the list. By default TocGenerator uses the KnpMenu Library ListRenderer class to output the HTML.

You can pass your instance of the ListRenderer class to TocGenerator::getHtmlMenu(). Or, you can pass in your own renderer (implements Knp\Menu\Renderer\RendererInterface).

For example, you may wish to use different CSS classes for your list items:

$options = [
    'currentAsLink' => false,
    'currentClass'  => 'curr_page',
    'ancestorClass' => 'curr_ancestor',
    'branch_class'  => 'branch
];

$renderer = new Knp\Menu\Renderer\ListRenderer(new Knp\Menu\Matcher\Matcher(), $options);

// Render the list
$tocGenerator = new TOC\TocGenerator();
$listHtml = $tocGenerator->getHtmlMenu($someHtmlContent, 1, 6, $renderer);

Customizing with Twig

The KnpMenu library offers more robust integration with the Twig Templating System than is offered by default with this library. You can take advantage of it by using the TwigRenderer that is bundled with KnpMenu:

$twigLoader = new \Twig_Loader_Filesystem(array(
    __DIR__.'/vendor/KnpMenu/src/Knp/Menu/Resources/views',
    // ...paths to your own Twig templates that render KnpMenus...
));

$twig = new \Twig_Environment($twigLoader);
$itemMatcher = \Knp\Menu\Matcher\Matcher();
$menuRenderer = new \Knp\Menu\Renderer\TwigRenderer($twig, 'knp_menu.html.twig', $itemMatcher);


$tocGenerator = new TOC\TocGenerator();

// Output the Menu using the template 
echo $menuRenderer->render($tocGenerator->getMenu($someHtmlContent));