At the moment this PR is "the mother of WORK IN PROGRESS"... 😄

Actually I don't have much to show yet, I'm primarily trying to point to PhrozenByte/pico-admin. I decided to start with development of the admin plugin, because it may give us some more ideas for Pico 1.1 2.0 (renamed 2016-12-12). Please use this PR to give feedback about the plugin (otherwise the discussion may get a bit fragmented).

@theshka: Do you think it makes sense to ask @picocms once again to convert his/her account to an GitHub Organization? This will allow us to use picocms/pico-admin instead... This is particularly meaningful when bearing in mind that I'm planning to create multiple repositories (picocms/pico-composer, picocms/pico-pagination, picocms/pico-tags, picocms/pico-feeds, picocms/pico-i18n, picocms/pico-search)...

Most importantly we have to make a decision about replacing Pico's default theme (see #297) with Pico 2.0 or to defer this until Pico 3.0. What are your opinions about this? (especially, but not solely, @theshka) My objections are primarily related to BC, but I have not formed a opinion about this yet. Please also refer to the "Decisions to make" section below.

Refer to http://picocms.org/phpDoc/pico-1.1/ for updated phpDoc class docs.

Plannings for the more distant future (i.e. Pico 3.0) can be found in #317. At the moment it's planned to let Pico 3.0 follow Pico 2.0 (i.e. no Pico 2.1).

As always, feedback is highly appreciated!

#edit: This release has been renamed to Pico 2.0 (previously Pico 1.1) on 2016-12-12, however we can't rename the branch, thus development will still happen on the pico-1.1 branch.

Planned changes to Pico's core

• Add Pico::VERSION constant
• Add includePico() function to prevent access to $this/Pico object in config/plugin files (use composer's includeFile() function instead?)
• [Feature Idea] Modular Config #330: Implement a modular config
  • Instead of using *.config.php files, use *.yml files to configure Pico. YAML is much easier to understand, more user friendly and (at least a bit) more error-tolerant, but still very powerful. Don't break BC by letting PicoDeprecated still read config/config.php.
• Allow Markdown configuration (Parsedown doesn't support much configuration, probably it will be limited to the optional usage of Parsedown instead of ParsedownExtra, Parsedown::setBreaksEnabled(), Parsedown::setMarkupEscaped() and Parsedown::setUrlsLinked())
• Create a (de facto never updated) pico-composer project to allow composer users to install Pico as dependency and benefit from composer's update mechanism; see @gilbitron's BaunCMS/Baun repo
  • Think about how users can easily install plugins with dependencies when they aren't using composer, but a pre-bundled release
• [Feature Idea] Internal 404 document #299: Integrated 404 Not Found page
• Add Pico::is404Content() method returning true when Pico::$requestFile doesn't exist (i.e. on404ContenLoading has been triggered)
• Remove PicoParsePagesContent
• Remove PicoExcerpt
• Don't sort pages when a unknown $config['pages_order_by'] is specified -- breaks BC
• Trigger the onMetaHeaders event only once, cache results of Pico::getMetaHeaders().
• Update README.md to use a screenshot hosted on our website
• Let users sort pages by arbitrary meta values (like Pico's sort_by Twig filter)
• Overhaul Pico::parseFileMeta(). Preserve BC with PicoDeprecated.
  • Don't lower unregistered meta headers on the first level unsolicited (e.g. SomeNotRegisteredKey: foobar in the YAML Frontmatter should result in $meta['SomeNotRegisteredKey'], not $meta['somenotregisteredkey']).
  • Don't compare registered meta headers case insensitive, rather allow registering multiple meta headers to result in the same meta value by flipping Pico::$metaHeaders
  • Let users explicitly set the formatted date in the YAML Frontmatter (e.g. date_formatted: Friday, 1st of December, 2000)
• Add a tree structure for all known pages

Planned changes to Pico's plugin system

• Allow Pico plugins to trigger custom events
• Add onSinglePageLoading event (new preliminary event to onSinglePageLoaded)
• When changing the $page parameter of the onSinglePageLoaded event to null, don't add this page to $pages (keeping $page['sub/page'] = null makes no sense, thus no BC break)
• Add plugin API versioning (new DummyPlugin::API_VERSION constant with Pico's major.minor version describing which API version the plugin expects; if the constant doesn't exist, assume 1.0); this allows us to overhaul the plugin event system in the future without breaking BC
  • parsedown extension #318: Add onParsedownRegistered event and pass $parsedown (instance of Parsedown) to allow extending erusev/parsedown
  • Replace onTwigRegistration event with onTwigRegistered and pass $twig (instance of Twig_Environment), remove $twig parameter from onPageRendering event
• Let PicoDeprecate differentiate between legacy levels (i.e. always enable the plugin to e.g. read config.php in Pico's root dir, but trigger deprecated events only when plugins of a specific legacy level are present)
• Allow to manually load plugins (i.e. add Pico::loadPlugin() method)
• Allow Pico plugins to be installed through composer.json
• Support multiple plugin dirs
• Add hook/event for Pico::getPageUrl()
• Add more events to Pico::readPages(), similar to the events of the current page
• Order plugins (execution order matters!) by evaluating their dependencies. Older plugins implicitly depend on PicoDeprecated. See tsort, marcj/topsort.php, haberco/topological-sort-php.
• Add a event between onPagesLoading and onPagesLoaded passing the unsorted pages array (e.g. onPagesDiscovered).
  • Also remove the $currentPage, $nextPage and $previousPage parameters from the onPagesLoaded event, fire a separate event to "publish" them
• Load plugins from plugins/<plugin name>.php (non-recursive) and plugins/<plugin name>/<plugin name>.php (the class file must be named after the directory) only. Plugins with multiple classes may need to register an autoloader on their own. Also see Should load_plugins() only load plugin_name.php? #203 -- breaks BC

Planned changes to Pico's UI (themes, Twig, routing, …)

• No "/index" in links in html code to index.md files #347: Drop the "index" part of URLs
• Support multiple theme dirs
• Make theme_url configurable; the default value should support that Pico::$themesDir is a arbitrary deep sub path of dirname($_SERVER['SCRIPT_FILENAME']) (i.e. index.php resp. httpdocs folder); otherwise fallback to themes (and not basename(Pico::$themesDir))
• Use Twig blocks in default theme (i.e. {% block replace_or_extend_me %}...{% endblock %})
• [Feature Idea] Pass $_GET to Twig template #305: Allow access to query string in Twig templates (i.e. $_GET superglobal)
• Support REQUEST_URI-based URL rewriting to allow a much simpler webserver configuration
• Use flexbox in Pico's default theme to pin the footer to the bottom of the window
• Drop {{ site_title }} and {{ rewrite_url }} in favour of their its {{ config.* }} equivalents. Rename {{ current_page }} to {{ page }}. Drop {{ is_front_page }} (use {% if page.id == "index" %} instead). Preserve BC with PicoDeprecated.
• Calculate the previous and next page for all pages (doesn't increase calculation time, array_search() in Pico::discoverCurrentPage() walks through all pages anyway). Drop {{ next_page }} and {{ previous_page }} in favor of their resulting {{ page.* }} equivalents (see above). Preserve BC with PicoDeprecated.
• Add only pages of the first level to the page navigation by default (e.g. page.md and sub/index.md, but not sub/page.md) -- breaks BC (more or less...)
• Ignore all pages starting with a _ for the page navigation by default (e.g. _meta.md and all files in _collection/ are skipped) -- breaks BC (more or less...)

Website & Documentation

See picocms/picocms.github.io#18

• Add Bountysource (merge enhancement/bountysource branch)

New official plugins/themes

The following plugins won't defer the release of Pico 2.0:

• Blog features
  • ☐ Pagination
  • ☐ Tags
  • ☐ RSS Feeds
  • ☑ Add hidden identifier in blog posts file naming #365: File Prefixes
• ☑ Robots (serve a robots.txt and sitemap.xml)
• ☐ Contact form
• ☐ Article Excerpts and Twig Filter #376 (comment): Excerpts
• ☐ Use Twitter Bootstrap 4 for Pico default theme. #297: Bootstrap 4 theme
• ☐ Editor/Page Admin