Create SHS enabled widget programatically through Form API

No, this isn't possible with Simple hierarchical select since it transforms term-reference widgets and doesn't create a widget on its own.

You'll need to create the elements using #ajax. See module Examples for in-depth details on how to do this.

It is possible.

Main idea:

$field_name = 'field_product' // Existing field with configured shs widget.

$field = field_info_field($field_name) // here should be an array from. Also you can define this array in some custom function.
$field = productfield_base_field(); // Easiest way - to copy this array from feature..

$instance = field_info_instance('node', $field_name, 'product_bundle'); // Instance array.
$instance = productfield_field_instance(); // U can also define it in some custom function.

// TAAA DAAAA Here is our field
$field_form = field_default_form('node', NULL, $field, $instance, LANGUAGE_NONE, NULL, $form, $form_state);

Hi - did you ever get this to work? I'm not having any luck.

  $vocabulary = taxonomy_vocabulary_machine_name_load('site_section');
  $taxonomy_tree = taxonomy_get_tree($vocabulary->vid);
  $terms = array();
  foreach ($taxonomy_tree as $key => $term) {
    $terms[$term->tid] = $term->name;
  }

  $form['my_container'] = array(
    '#type' => 'container',
    '#attributes' => array(
      'class' => array(
        'field-widget-taxonomy-shs',
        ),
      ),
    '#tree' => 1,
  );
  $form['my_container']['my_field'] = array(
    '#type' => 'select',
    '#title' => t('My field'),
    '#options' => $terms,
    '#attributes' => array('class' => array('shs-enabled')),
    '#element_validate' => array('shs_field_widget_validate'),
    '#after_build' => array('shs_field_widget_afterbuild'),
    '#shs_settings' => array(
      'create_new_levels' => 0,
      'create_new_terms' => 0,
      'force_deepest' => 0,
      'node_count' => 0,
      'test_create_new_terms' => array(),
      'required' => TRUE,
    ),
    '#language' => NULL,
    '#field_name' => 'my_field',
    '#default_value' => 0,
    '#field_parents' => NULL,
    '#shs_vocabularies' => array($vocabulary),
  );

How do that in drupal 8?

Thanks.

Want to know too, how to do this in D8

@gmangones, did you find the way?

For D8 integration it is tricky.
I had great pains to get the selected value sent in the submit callback, as options were set in JS and would disappear from the values of the form_state.
The solution was to manually send in the field declaration the options (that are also generated by SHS in JS) and split the declaration of the "container" and the "widget" form fields.

$field_name = 'term_field';
$vid = 'tags';
$tag_options = \Drupal::entityTypeManager()->getStorage('taxonomy_term')->getQuery()->condition('vid', $vid)->execute();

$shs = [
  'settings' => [
    'required' => TRUE,
    'multiple' => FALSE,
    'anyLabel' => t('- Select a term -'),
    'anyValue' => '_none',
    'addNewLabel' => t('Add another item'),
    'force_deepest' => TRUE,
    'create_new_items' => FALSE,
    'create_new_levels' => FALSE,
    'display_node_count' => FALSE,
  ],
  'bundle' => $vid,
  'baseUrl' => \Drupal\Core\Url::fromUri('base:/shs-term-data')->toString(),
  'cardinality' => 1,
  'parents' => [[['parent' => 0, 'defaultValue' => '_none']]],
  'defaultValue' => NULL,
];

$form[$field_name] = [
  '#type' => 'container',
];

$form[$field_name]['widget'] = [
  '#type' => 'select',
  '#title' => t('Select a term'),
  '#key_column' => 'tid',
  '#field_parents' => [],
  '#field_name' => $field_name,
  '#shs' => $shs,
  '#options' => $tag_options,
  '#attributes' => [
    'class' => ['shs-enabled'],
  ],
  '#attached' => [
    'library' => ['shs/shs.form'],
  ],
  '#element_validate' => [[
    '\Drupal\shs\Plugin\Field\FieldWidget\OptionsShsWidget',
    'validateElement',
  ]],
  '#after_build' => [[
    '\Drupal\shs\Plugin\Field\FieldWidget\OptionsShsWidget',
    'afterBuild',
  ]],
];

@pratip.ghosh did you find a way to implement this in D8?

Anyone looking for the solution in D8 can try this :

Created two form fields and populated first field with parent items and based on that value wrote a callback to load all children items which will be populated to the second drop down using jquery.

In comment #8 just change

  $shs = [ 
    // ...
   ]; 

to

    $shs = [
      'settings' => [
        'required' => TRUE,
        'multiple' => FALSE,
        'anyLabel' => t('- Any -'),
        'anyValue' => 'All',
        'addNewLabel' => '',
        'force_deepest' => FALSE,
        'create_new_items' => FALSE,
        'create_new_levels' => FALSE,
        'display_node_count' => FALSE,
      ],
      'bundle' => $vid,
      'baseUrl' => 'shs-term-data',
      'cardinality' => 1,
      'parents' => [[['parent' => 0, 'defaultValue' => 'All']]],
      'defaultValue' => NULL,
      'labels' => [
        t('Country'),
        t('Region'),
        t('City'),
      ],
    ];

and it will work, tested for shs-8.x-1.x-dev version.

Drupal 8 - Create SHS enabled widget programatically through Form API

For Drupal 8 with unlimited multi-value SHS field in Custom Form

buildForm() method in example of custom form

  public function buildForm(array $form, FormStateInterface $form_state) {
    $field_name = 'field_shs_field_name';
    $vid = 'voc_shs_taxonomy';
    $title_field = $this->t('SHS Field Name');
    $anyLabel = $this->t('- None -');
    $addNewLabel = $this->t('Add another item');
    $cardinality = -1;

    $terms =\Drupal::entityTypeManager()->getStorage('taxonomy_term')->loadTree($vid);
    $term_data = array();
    $term_data['_none'] = $anyLabel;
    foreach ($terms as $term) {
      $term_name = ($term->parents[0]==0)? $term->name : '-' . $term->name;
      $term_data[$term->tid] = $term_name;
    }
		
    $form[$field_name]['#type'] = 'container';
		
    $settings_additional = [
      'force_deepest' => TRUE,
      'create_new_items' => FALSE,
      'create_new_levels' => FALSE,
      'display_node_count' => FALSE,
      'required' => FALSE,
      'multiple' => TRUE,
      'anyLabel' => $anyLabel,
      'anyValue' => '_none',
      'addNewLabel' => $addNewLabel,
    ];	
		
    $settings_shs = [
      'settings' => $settings_additional,
      'bundle' => $vid,
      'baseUrl' => 'shs-term-data',
      'cardinality' => $cardinality,
      'parents' => [[['parent' => 0, 'defaultValue' => '_none']]],
      'defaultValue' => NULL,
      'labels' => [ $this->t('Level 1'), $this->t('Level 2'), ],
    ];
		
    $form[$field_name]['widget'] = [
      '#title' => $title_field,
      '#description' => "",
      '#field_parents' => [],
      '#required' => FALSE,
      '#delta' => 0,
      '#weight' => 0,
      '#element_validate' => [[
        'Drupal\shs\Plugin\Field\FieldWidget\OptionsShsWidget', 
        'validateElement',
      ]],
      '#key_column' => 'target_id',
      '#type' => 'select',
      '#options' => $term_data,
      '#default_value' => [],
      '#multiple' => TRUE,
      '#shs' => $settings_shs,
      '#attributes' => [ 'class' => ['shs-enabled'] ],
      '#attached' => [ 'library' => ['shs/shs.form'] ],
      '#after_build' => [[
        'Drupal\shs\Plugin\Field\FieldWidget\OptionsShsWidget', 
        'afterBuild',
      ]],
      '#field_name' => $field_name,
      '#parents' => [$field_name],
      '#tree' => TRUE,
    ];

    $form['actions']['#type'] = 'actions';
    $form['actions']['submit'] = [
      '#type' => 'submit',
      '#value' => $this->t('Save'),
      '#button_type' => 'primary',
    ];
    return $form;
  }

submitForm() method in example of custom form

  public function submitForm(array &$form, FormStateInterface $form_state) {
    $field_name = 'field_shs_field_name';
    $shs_values = $form_state->getValue($field_name);
    $tids = [];
    foreach($shs_values AS $val_i) {
      $tids[] = $val_i['target_id'];
    }
    $this->messenger()->addStatus($this->t('Your ID terms are: "@tids"', ['@tids' => implode(', ',$tids) ]));
  }

Tested and works in version 8.x-1.0-alpha4

Hi, comment #8 and #11 combined work for my.

Hi,
comment #8 and #11 combined work for me.
And i also checked #13, its also working if we need multiple values, only issue when we add more all values hide then show again.
Thanks