unclecheese/reflection-templates

Provides introspection of SilverStripe templates with an API for getting variables and blocks, much like the PHP ReflectionClass.

dev-master 2016-10-18 01:33 UTC

README

A set of classes that introspect SilverStripe templates, getting metadata about variables and blocks, much like PHP's ReflectionClass.

Installation

composer require unclecheese/reflection-templates:dev-master

Requirements

SilverStripe 3.1 or higher

Usage

Given a template such as this:

<div>
  <h2>$Headline</h2>
  <div>$Image.CroppedImage(200,200)</div>
  <h3>$Category.Title</h3>
  <% if $Featured %>it's featured<% end_if %>
  <ul>
  <% loop $Items %>
    <li>$Title ($Date.Nice)</li>
    <% if $Articles %>
    <ul>
      <% loop $Articles %>
      <li>This article, called $ArticleTitle is related to $Up.Title <% if $Published %>published<% end _if %></li>
      <% end_loop %>
     </ul>
    <% end_if %>
  <% end_loop %>

  <% with $FeaturedProduct %>
    <h3>$Description</h3>
  <% end_with %>
</div>

We can introspect it using a ReflectionTemplate like so:

 $reflector = ReflectionTemplate::create();
 $reflector->process(file_get_contents('/path/to/template.ss'));

 foreach($reflector->getTopLevelVars() as $varName => $type) {
    echo "The template variable $varName is likely a $type\n";
 }

 foreach($reflector->getTopLevelBlocks() as $block) {
     echo "There is a block at the top level named {$block->getName()}\n";
     echo $block->isLoop() ? "\tThis block is a loop\n" : "\tThis block is a with\n";
     foreach($block->getVars() as $var => $type) {
        echo "\tThe top level block {$block->getName()} contains a variable named $var that is likely a $type\n";
     }
     foreach($block->getChildren() as $child) {
        echo "\tThere is a child block named {$child->getName()}. It has the following vars:\n";
        foreach($child->getVars() as $v => $t) {
            echo "\t\tThe nested block {$child->getName()} contains a variable named $v that is likely a $t\n";
        }
     }
 }      

This produces the following result:

The template variable Headline is likely a Text
The template variable Image is likely a Image
The template variable Category is likely a has_one
The template variable Featured is likely a Boolean
There is a block at the top level named Items
    This block is a loop
    The top level block Items contains a variable named Title that is likely a Text
    The top level block Items contains a variable named Date that is likely a Date
    There is a child block named Articles. It has the following vars:
        The nested block Articles contains a variable named ArticleTitle that is likely a Text
        The nested block Articles contains a variable named Published that is likely a Boolean
There is a block at the top level named FeaturedProduct
    This block is a with
    The top level block FeaturedProduct contains a variable named Description that is likely a Text

Contextual template reflection

You can use one of the two context-sensitive reflectors to surface only variables and blocks that are user-defined.

  • SiteTreeReflectionTemplate comes loaded with context about methods and variables that are made available to all SiteTree and ContentController contexts, and filters out things like $Menu, $SiteConfig, etc.
  • EmailReflectionTemplate works similarly, filtering out variables like To, Subject, etc., that are made available to all emails.

For all that is good and holy in this world, WHY?!

I found myself in need of it recently, and I had all this code kicking around from the old SilverSmith project, and decided its best not left to sit and rot into oblivion. Hopefully someone else can make use of this insanity.

Todo

Add a task that will generate PHP classes given a template