Leading whitespace in field template output

[xportde]

Hello together,

I have a question about field templates: When the output of a field template (using with $page->render->field) starts with a whitespace, it will be automatically trimmed off. Is it possible to suppress this behaviour, in case we need the whitespace explicitely?

Thanks in advance,

Thomas.

[adrian]

Is it only when using field templates, or is the trimming happening on a textarea field and as such would happen even if you output it directly? If so, take a look at this issue (https://github.com/processwire/processwire-issues/issues/459) and the noTrim option.

[xportde]

No, is happens actually in a SelectOptions field ($value) render template, that generates css classes depending on settings made by user:

$css = '';

foreach ($value as $device) {
    switch ($device->value) {
        case 'mobile':
            $css .= ' sm-hide';
            break;
        case 'tablet':
            $css .= ' md-hide';
            break;
        case 'desktop':
            $css .= ' xlg-hide lg-hide';
            break;
    }
}

echo $css;

In case of checking the mobile option, $css contains ' sm-hide'. But in the calling template, only 'sm-hide' is delivered, without the trailing whitespace:

<section class="class1 class2 class3<?=$page->render->devices?>">
  
is rendered as
  
<section class="class1 class2 class3sm-hide">

Of course we could set the space directly after 'class3', but in case of no selected device option it would be unnecessary.

[Robin S]

@xportde, the ouput is trimmed of whitespace because the field render makes use of TemplateFile::render and by default the trim option is set to true.

/**
 * Trim leading/trailing whitespace from rendered output?
 * 
 * @var bool
 * 
 */
protected $trim = true;

There's no built-in way to change that setting in the render() call but you can change it with a hook if it's important:

$wire->addHookBefore('TemplateFile::render', function(HookEvent $event) {
	$tpl = $event->object;
	if($tpl->field && $tpl->field->name === 'your_field_name') {
		$tpl->setTrim(false);
	}
});

 

[xportde]

@Robin S I knew, that there is a way to do this, because it's ProcessWire! Thank you so much for the hint!