3: Component Parameters

You cannot only pass custom parameters to newly instantiated components. There are a few core-parameters that influence the component's behavior as well.

directory

<?php
namespace ProcessWire;

$myComponent = wire('twack')->getNewComponent('PageTitleOutput', [
  'directory' => 'general'
]);

Setting a value for the directory-parameter makes Twack to look for the component files under a different location. With the code above, we instruct Twack to initialize a PageTitleOutput-component which is located not under site/templates/components/page_title_output/page_title_output.class.php but under site/templates/components/general/page_title_output/page_title_output.class.php.

The directory-path is relative to the components-directory, which is defined in the module-configuration. You can also set it to an empty string to instruct Twack to look for a component at the root-level. This is especially useful when you add a child-component that is not located in your parent components directory:

<?php
namespace ProcessWire;

class HelloWorld extends TwackComponent {
  public function __construct($args) {
    parent::__construct($args);

    // Our "General"-component is located under site/templates/components/general/general.class.php:
    $this->addComponent('General', ['directory' => '']);
  }
}

page

Each component has a ProcessWire page it is internally linked with. Per default that would be the page which was initially called by the user - the same as in wire('page'). You can access the component's page via $this->page:

<?php
namespace ProcessWire;
?>
<h2><?= $this->page->title; ?>(<?= $this->page->id; ?>)</h2>

site/templates/components/general/page_title_output.view.php

But you can also change the internally linked page. For example, if you want to show a list of pages you can call our PageTitleOutputcomponent on each page:

<?php
namespace ProcessWire;

foreach(wire('pages')->find('template.name=newsitem') as $item){
  $myComponent = wire('twack')->getNewComponent('PageTitleOutput', [
    'directory' => 'general',
    'page' => $item
  ]);
  echo $myComponent->render();
}

parameters

When you pass custom values to the new component they will be available in the component constructor's $args array. You can work with these values and set them via $this->my_value = $args['my_value']; to a component-attribute that will be also accessible in the view. If you don't want to do any logic and validation with a custom value, you can set it as a component-attribute right in the initialization step. Add a parameters array with your custom parameters, that should be available as a component attribute and in the view.

<?php
namespace ProcessWire;

$myComponent = wire('twack')->getNewComponent('PageTitleOutput', [
  'directory' => 'general',
  'parameters' => [
    'showTitle' => false
  ]
]);
echo $myComponent->render();

viewname

Even though I haven't needed it much in my components so far, it's possible to set a custom view name. With this feature, you could for example initialize a component but say, that it should use a different view file than the default {class_name}.view.php.

<?php
namespace ProcessWire;

$myComponent = wire('twack')->getNewComponent('PageTitleOutput', [
  'directory' => 'general',
  'viewname' => 'OnlyDescription'
]);
echo $myComponent->render();

The example above would instruct the component to use the view site/templates/components/general/page_title_output/only_description.view.php.

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