This CodeLet let you programmatically create a form page and render same form on a block. Create custom module and follow CodeLet instruction to create a form and block programmatically.
CodeLet
Create a file name with "custom.routing.yml" on your module's root directory and place bellowed code on it.
custom.my-custom-form:
path: '/my-custom-form'
defaults:
_form: 'Drupal\custom\Form\MyCustomForm'
_title: 'Custom Form'
requirements:
_permission: 'access content'
<?php//Drupal8 form: let’s define our simple MyCustomForm class inside src/Form/MyCustomForm.php/*** @file* Contains \Drupal\custom\Form\MyCustomForm.*/namespace Drupal\custom\Form;use Drupal\Core\Form\FormBase;use Drupal\Core\Form\FormStateInterface;/*** My Custom form.*/class MyCustomForm extends FormBase { /** * {@inheritdoc} */ public function getFormId() { return 'my_custom_form'; } /** * {@inheritdoc} */ public function buildForm(array $form, FormStateInterface $form_state) { $form['name'] = array( '#type' => 'textfield', '#size' => 15, '#placeholder' => t('Name'), ); $form['description'] = array( '#type' => 'textarea', '#required' => TRUE, '#placeholder' => t('Description'), ); $form['email'] = array( '#type' => 'email', '#required' => TRUE, '#placeholder' => t('E-mail address'), ); $form['submit'] = array( '#type' => 'submit', '#value' => t('Submit'), ); return $form; } /** * {@inheritdoc} */ public function validateForm(array &$form, FormStateInterface $form_state) { if ($form_state->getValue('name') == '' ) { $form_state->setErrorByName('name', t('This is a required field.')); } } /** * {@inheritdoc} */ public function submitForm(array &$form, FormStateInterface $form_state) { $name = $form_state->getValue('name'); $description = $form_state->getValue('description'); $email = $form_state->getValue('email'); $message = t('Your information has been successfully submitted.') ; drupal_set_message($message); }}?><?php// Drupal8 block: let’s define our simple CustomBlock class inside src/Plugin/Block/CustomBlock.php// This "Custom Block" will be available at admin block interface you can place it on any region./*** @file* Contains \Drupal\custom\Plugin\Block\CustomBlock.*/namespace Drupal\custom\Plugin\Block;use Drupal\Core\Block\BlockBase;/*** Provides Custom Block.** @Block(* id = "my_custom_block",* admin_label = @Translation("Custom Block"),* category = @Translation("Blocks")* )*/class CustomBlock extends BlockBase { /** * {@inheritdoc} */ public function build() { $build = array(); $build['#markup'] = '<h2>' . t('My Custom Form') . '</h2>'; $build['form'] = \Drupal::formBuilder()->getForm('Drupal\custom\Form\MyCustomForm'); return $build; }}?>Info file details
name: Custom module
description: 'Custom module for Enhance feature'
type: module
core: 8.x