Get content from a Craft CMS matrix block within a plugin
You need to know the block ID (I'm getting it from the Post).
// get the matrix block $block = craft()->matrix->getBlockById($blockId']); // get the custom field $customField = $block->getFieldValue('customFieldName');
Hat tip, but beware the
getFieldValue shortcut described by Brandon didn't work for me. That might be because my matrix field is tied to a Craft Commerce order, not a standard entry.