I have a form and i call an API tahta brings huge data on build form.
But when i call Ajax on other form elements , the whole code for form(buildForm, constructor ) is called again and again. There is a way to check triggering element but the code is called twice again once due to ajax Callback and once due to validateForm. I want a solution so that the Api are only called once, what solution i can use for this
<?php
namespace Drupalfapi_exampleForm;
use DrupalCoreFormFormStateInterface;
/**
* Implements the ajax demo form controller.
*
* This example demonstrates using ajax callbacks to populate the options of a
* color select element dynamically based on the value selected in another
* select element in the form.
*
* @see DrupalCoreFormFormBase
* @see DrupalCoreFormConfigFormBase
*/
class AjaxDemo extends DemoBase {
/**
* {@inheritdoc}
*/
public function getFormId() {
return 'fapi_example_ajax_demo';
}
/**
* {@inheritdoc}
*/
public function buildForm(array $form, FormStateInterface $form_state) {
$form('temperature') = (
'#title' => $this->t('Temperature'),
'#type' => 'select',
'#options' => $this->getColorTemperatures(),
'#empty_option' => $this->t('- Select a color temperature -'),
'#ajax' => (
// Could also use (get_class($this), 'updateColor').
'callback' => '::updateColor',
'wrapper' => 'color-wrapper',
),
);
print("API call");
$form('color_wrapper') = (
'#type' => 'container',
'#attributes' => ('id' => 'color-wrapper'),
);
$temperature = $form_state->getValue('temperature');
if (!empty($temperature)) {
$form('color_wrapper')('color') = (
'#type' => 'select',
'#title' => $this->t('Color'),
'#options' => $this->getColorsByTemperature($temperature),
);
}
// Add a submit button that handles the submission of the form.
$form('actions') = (
'#type' => 'actions',
'submit' => (
'#type' => 'submit',
'#value' => $this->t('Submit'),
),
);
return $form;
}
/**
* Ajax callback for the color dropdown.
*/
public function updateColor(array $form, FormStateInterface $form_state) {
return $form('color_wrapper');
}
/**
* Returns colors that correspond with the given temperature.
*
* @param string $temperature
* The color temperature for which to return a list of colors. Can be either
* 'warm' or 'cool'.
*
* @return array
* An associative array of colors that correspond to the given color
* temperature, suitable to use as form options.
*/
protected function getColorsByTemperature($temperature) {
return $this->getColors()($temperature)('colors');
}
/**
* Returns a list of color temperatures.
*
* @return array
* An associative array of color temperatures, suitable to use as form
* options.
*/
protected function getColorTemperatures() {
return array_map(function ($color_data) {
return $color_data('name');
}, $this->getColors());
}
public function validateForm(array &$form, FormStateInterface $form_state) {
$form_values = $form_state->getValues();
print("Sssaaa");
}
/**
* Returns an array of colors grouped by color temperature.
*
* @return array
* An associative array of color data, keyed by color temperature.
*/
protected function getColors() {
return (
'warm' => (
'name' => $this->t('Warm'),
'colors' => (
'red' => $this->t('Red'),
'orange' => $this->t('Orange'),
'yellow' => $this->t('Yellow'),
),
),
'cool' => (
'name' => $this->t('Cool'),
'colors' => (
'blue' => $this->t('Blue'),
'purple' => $this->t('Purple'),
'green' => $this->t('Green'),
),
),
);
}
}