FileCompilerTags not working for field rendering

[dreerr]

Short description of the issue

With the module FileCompilerTags activated it is possible to use {var} or {var.property} variables in markup sections of a file. Sadly this does not work for template files for fields stored in templates/fields/

Expected behavior

When using {var} in a file in templates/fields/ it should render the value.

Actual behavior

The {var} is not parsed.

Steps to reproduce the issue

1. Create a field template
2. Use a tag like {value.title}

Setup/Environment

ProcessWire: 3.0.64
PHP: 7.1.4
Webserver: Apache/2.4.18 (Unix)
MySQL: 5.7.17

[ryancramerdesign]

In your file that's in templates/fields/, are you using a "namespace ProcessWire;" at the top? If so, try removing that, so that there is no namespace specified. Those field rendering files don't get touched by the compiler if a namespace is present.

[dreerr]

No, there is no namespace declaration, also not in the corresponding template file.

[netcarver]

Is this issue impacting anyone other than dreer?

[matjazpotocnik]

I can confirm what @dreerr found out. Possible solution:

$wire->addHookAfter('FileCompiler::compileData', function(HookEvent $event) {
	$data = $event->return;
	$sourceFile = $event->arguments[1];
	
	//only compile files inside fields folder
	if(strpos($sourceFile, '/fields/') === false) return;
	
	$compilers = array();
	foreach($this->wire('modules')->findByPrefix('FileCompiler', true) as $module) {
		if(!$module instanceof FileCompilerModule) continue;
		$runOrder = (int) $module->get('runOrder');
		while(isset($compilers[$runOrder])) $runOrder++;
		$compilers[$runOrder] = $module;
	}

	if(count($compilers)) {
		ksort($compilers);
		foreach($compilers as $module) {
			$module->setSourceFile($sourceFile);
			$data = $module->compile($data);
		}
	}
	
	$event->return = $data;
});

Also, this is what Ryan said in blog:

This particular module is in the core presently, but will likely be moved out of the core once 3.x has representation in the modules directory. But for those interested in implementing their own FileCompiler module(s), we'd encourage you to use the FileCompilerTags module as a potential Hello World example of implementing this module class.

[netcarver]

@matjazpotocnik Thank you, added labels accordingly.