01-what-you-think.php

<?php

function formtable_form_table_form($form = array(), &$form_state) {
  $form['table'] = array(
    '#theme' => 'table',
    '#header' => array(t('Column 1'), t('Column 2')),
    '#rows' => array(
      // First row.
      'r1' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 2'),
        ),
      ),
      // Second row.
      'r2' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 2'),
        ),
      ),
    ),
  );

  // Add a submit button for fun.
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
}

02-build-form.php

<?php
/**
 * Page Callback / Form Builder for the table form.
 */
function formtable_form_table_form($form = array(), &$form_state) {
  $form['table'] = array(
    // Theme this part of the form as a table.
    '#theme' => 'formtable_form_table',
    // Pass header information to the theme function.
    '#header' => array(t('Column 1'), t('Column 2')),
    // Rows in the form table.
    'rows' => array(
      // Make it a tree for easier traversing of the entered values on submission.
      '#tree' => TRUE,
      // First row.
      'r1' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 2'),
        ),
      ),
      // Second row.
      'r2' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 2'),
        ),
      ),
    ),
  );
 
  // Add a submit button for fun.
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
 
  return $form;
}

03-register-theme-callback.php

<?php
/**
 * Implementation of hook_theme().
 */
function formtable_theme() {
  return array(
    'formtable_form_table' => array(
      // The renderable element is the form.
      'render element' => 'form',
    ),
  );
}

04-create-theme-callback.php

<?php

/**
 * Theme callback for the form table.
 */
function theme_formtable_form_table(&$variables) {
  // Get the useful values.
  $form = $variables['form'];
  $rows = $form['rows'];
  $header = $form['#header'];
 
  // Setup the structure to be rendered and returned.
  $content = array(
    '#theme' => 'table',
    '#header' => $header,
    '#rows' => array(),
  );
 
  // Traverse each row.  @see element_chidren().
  foreach (element_children($rows) as $row_index) {
    $row = array();
    // Traverse each column in the row.  @see element_children().
    foreach (element_children($rows[$row_index]) as $col_index) {
      // Render the column form element.
      $row[] = drupal_render($rows[$row_index][$col_index]);
    }
    // Add the row to the table.
    $content['#rows'][] = $row;
  }
 
  // Redner the table and return.
  return drupal_render($content);
}

05-full-module-file.php

<?php
 
/**
 * Implementation of hook_menu().
 */
function formtable_menu() {
  $items = array();
 
  // A page to demonstrate theming form elements in a table.
  $items['formtable'] = array(
    'title' => 'Form Table Example',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('formtable_form_table_form'),
    'access callback' => TRUE,
  );
  
  return $items;
}
 
/**
 * Implementation of hook_theme.
 */
function formtable_theme() {
  return array(
    'formtable_form_table' => array(
      // The renderable element is the form.
      'render element' => 'form',
    ),
  );
}
 
/**
 * Page Callback / Form Builder for the table form.
 */
function formtable_form_table_form($form = array(), &$form_state) {
  $form['table'] = array(
    // Theme this part of the form as a table.
    '#theme' => 'formtable_form_table',
    // Pass header information to the theme function.
    '#header' => array(t('Column 1'), t('Column 2')),
    // Rows in the form table.
    'rows' => array(
      // Make it a tree for easier traversing of the entered values on submission.
      '#tree' => TRUE,
      // First row.
      'r1' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 1 Column 2'),
        ),
      ),
      // Second row.
      'r2' => array(
        'c1' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 1')
        ),
        'c2' => array(
          '#type' => 'textfield',
          '#title' => t('Row 2 Column 2'),
        ),
      ),
    ),
  );
 
  // Add a submit button for fun.
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
 
  return $form;
}
 
/**
 * Theme callback for the form table.
 */
function theme_formtable_form_table(&$variables) {
  // Get the userful values.
  $form = $variables['form'];
  $rows = $form['rows'];
  $header = $form['#header'];
 
  // Setup the structure to be rendered and returned.
  $content = array(
    '#theme' => 'table',
    '#header' => $header,
    '#rows' => array(),
  );
 
  // Traverse each row.  @see element_chidren().
  foreach (element_children($rows) as $row_index) {
    $row = array();
    // Traverse each column in the row.  @see element_children().
    foreach (element_children($rows[$row_index]) as $col_index) {
      // Render the column form element.
      $row[] = drupal_render($rows[$row_index][$col_index]);
    }
    // Add the row to the table.
    $content['#rows'][] = $row;
  }
 
  // Redner the table and return.
  return drupal_render($content);
}