Report render array output error in Metadata Display preview

[aksm]

What?

When a render array output is generated via a metadata display template, e.g. {{ data.ia_an_array_dont_uoutput_me }}, the error (see screenshot below) is not reported in the preview.

Todo:

• Add a report of the KEYS used in the template v/s the JSON (basically a coverage of their use of values (from the source) in the output).
  1. Get all keys on the selected ADO
  2. Check their type (single value, iterable)
  3. Rename them to data.thekeyname in a function
  4. Parse the Twig checking how many times thekeyname is mentioned or attribute(‘thekeyname’, data) and in which lines

See for reference (no longer working due to changed interface):

format_strawberryfield/src/Entity/MetadataDisplayEntity.php

Lines 435 to 459 in 2e5cc2a

	private function getTwigVariableNames(ModuleNode $nodes): array {
	$variables = [];
	foreach ($nodes as $node) {
	if ($node instanceof \Twig_Node_Expression_Name) {
	$name = $node->getAttribute('name');
	$variables[$name] = $name;
	}
	elseif ($node instanceof \Twig_Node_Expression_Constant && $nodes instanceof \Twig_Node_Expression_GetAttr) {
	$value = $node->getAttribute('value');
	if (!empty($value) && is_string($value)) {
	$variables[$value] = $value;
	}
	}
	elseif ($node instanceof \Twig_Node_Expression_GetAttr) {
	$path = implode('.', $this->getTwigVariableNames($node));
	if (!empty($path)) {
	$variables[$path] = $path;
	}
	}
	elseif ($node instanceof \Twig_Node) {
	$variables += $this->getTwigVariableNames($node);
	}
	}
	return $variables;
	}

[DiegoPino]

Solved for main preview via #274
@aksm we need an issue that matches this one on AMI!