XHP: Migration

You can incrementally port code to use XHP.

The basis for all these possibilities is this function:

function render_component($text, $uri) {
  $uri = htmlspecialchars($uri);
  $text = htmlspecialchars($text);
  return "<a href=\"$uri\">$text</a>";
}

This could be called from many places.

Convert Leaf Functions

You can simply use XHP in render_component:

function render_component($text, $uri) {
  $link = <a href={$uri}>{$text}</a>;
  return $link->toString();
}

You are converting render_component into a safer function without the need for explicit escaping, etc. But you are still passing strings around in the end.

Use a Class

You could make render_component into a class:

// Assume class Uri
class :ui:component-link extends :x:element {
  attribute Uri $uri @required;
  attribute string $text @required;
  protected function render(): XHPRoot {
    return
      <a href={$this->:uri}>{$this->:text}</a>;
  }
}

Keep a legacy render_component around while you are converting the old code that uses render_component to use the class.

function render_component(string $text, Uri $uri): string {
  return (<ui:component-link uri={$uri} text={$text} />)->toString();
}

ExtendingXHP:

GuidelinesXHP: