Rebuild article system

lib/render_php.php

@@ -0,0 +1,30 @@
+<?php
+use Symfony\Component\Yaml\Yaml;
+
+function render_php($file) {
+  ob_start();
+  #include __DIR__ . '/' . $file;
+  include $file;
+  $html = ob_get_clean();
+  $meta = [];
+
+  # Split off head matter
+  #
+  # this pattern uses the 'ms' modifier to treat multiline strings as a
+  # single string, and let '\s', '.' etc treat newlines as whitespace
+  # I match an _optional_ HTML ( '<!-- nnnn -->') comment if we want to wrap
+  # the headmatter in a comment.
+  #
+  # The headmatter is delimited by either '----' or '++++' as per
+  # Markdown/yaml standards.
+  # Technical note that '+' is a regex character so \+{3,} instead of ++++
+  if (preg_match('/^(<!--\s*)?(-{3,}|\+{3,})\s*(.*?)(-{3,}|\+{3,})\s*(-->)?\s*(.*)/ms',$html, $parts) === 1) {
+     $html = $parts[6];
+     $meta = array_merge($meta,Yaml::parse($parts[3]));
+  }
+
+  return [
+     'html' => $html,
+     'meta' => $meta,
+  ];
+}