/**
* @file
* Form features.
*/
/**
* Triggers when a value in the form changed.
*
* The event triggers when content is typed or pasted in a text field, before
* the change event triggers.
*
* @event formUpdated
*/
/**
* Triggers when a click on a page fragment link or hash change is detected.
*
* The event triggers when the fragment in the URL changes (a hash change) and
* when a link containing a fragment identifier is clicked. In case the hash
* changes due to a click this event will only be triggered once.
*
* @event formFragmentLinkClickOrHashChange
*/
(function ($, Drupal, debounce) {
/**
* Retrieves the summary for the first element.
*
* @return {string}
* The text of the summary.
*/
$.fn.drupalGetSummary = function () {
const callback = this.data('summaryCallback');
return this[0] && callback ? $.trim(callback(this[0])) : '';
};
/**
* Sets the summary for all matched elements.
*
* @param {function} callback
* Either a function that will be called each time the summary is
* retrieved or a string (which is returned each time).
*
* @return {jQuery}
* jQuery collection of the current element.
*
* @fires event:summaryUpdated
*
* @listens event:formUpdated
*/
$.fn.drupalSetSummary = function (callback) {
const self = this;
// To facilitate things, the callback should always be a function. If it's
// not, we wrap it into an anonymous function which just returns the value.
if (typeof callback !== 'function') {
const val = callback;
callback = function () {
return val;
};
}
return (
this.data('summaryCallback', callback)
// To prevent duplicate events, the handlers are first removed and then
// (re-)added.
.off('formUpdated.summary')
.on('formUpdated.summary', () => {
self.trigger('summaryUpdated');
})
// The actual summaryUpdated handler doesn't fire when the callback is
// changed, so we have to do this manually.
.trigger('summaryUpdated')
);
};
/**
* Prevents consecutive form submissions of identical form values.
*
* Repetitive form submissions that would submit the identical form values
* are prevented, unless the form values are different to the previously
* submitted values.
*
* This is a simplified re-implementation of a user-agent behavior that
* should be natively supported by major web browsers, but at this time, only
* Firefox has a built-in protection.
*
* A form value-based approach ensures that the constraint is triggered for
* consecutive, identical form submissions only. Compared to that, a form
* button-based approach would (1) rely on [visible] buttons to exist where
* technically not required and (2) require more complex state management if
* there are multiple buttons in a form.
*
* This implementation is based on form-level submit events only and relies
* on jQuery's serialize() method to determine submitted form values. As such,
* the following limitations exist:
*
* - Event handlers on form buttons that preventDefault() do not receive a
* double-submit protection. That is deemed to be fine, since such button
* events typically trigger reversible client-side or server-side
* operations that are local to the context of a form only.
* - Changed values in advanced form controls, such as file inputs, are not
* part of the form values being compared between consecutive form submits
* (due to limitations of jQuery.serialize()). That is deemed to be
* acceptable, because if the user forgot to attach a file, then the size of
* HTTP payload will most likely be small enough to be fully passed to the
* server endpoint within (milli)seconds. If a user mistakenly attached a
* wrong file and is technically versed enough to cancel the form submission
* (and HTTP payload) in order to attach a different file, then that
* edge-case is not supported here.
*
* Lastly, all forms submitted via HTTP GET are idempotent by definition of
* HTTP standards, so excluded in this implementation.
*
* @type {Drupal~behavior}
*/
Drupal.behaviors.formSingleSubmit = {
attach() {
function onFormSubmit(e) {
const $form = $(e.currentTarget);
const formValues = $form.serialize();
const previousValues = $form.attr('data-drupal-form-submit-last');
if (previousValues === formValues) {
e.preventDefault();
} else {
$form.attr('data-drupal-form-submit-last', formValues);
}
}
$('body')
.once('form-single-submit')
.on('submit.singleSubmit', 'form:not([method~="GET"])', onFormSubmit);
},
};
/**
* Sends a 'formUpdated' event each time a form element is modified.
*
* @param {HTMLElement} element
* The element to trigger a form updated event on.
*
* @fires event:formUpdated
*/
function triggerFormUpdated(element) {
$(element).trigger('formUpdated');
}
/**
* Collects the IDs of all form fields in the given form.
*
* @param {HTMLFormElement} form
* The form element to search.
*
* @return {Array}
* Array of IDs for form fields.
*/
function fieldsList(form) {
const $fieldList = $(form)
.find('[name]')
.map(
// We use id to avoid name duplicates on radio fields and filter out
// elements with a name but no id.
(index, element) => element.getAttribute('id'),
);
// Return a true array.
return $.makeArray($fieldList);
}
/**
* Triggers the 'formUpdated' event on form elements when they are modified.
*
* @type {Drupal~behavior}
*
* @prop {Drupal~behaviorAttach} attach
* Attaches formUpdated behaviors.
* @prop {Drupal~behaviorDetach} detach
* Detaches formUpdated behaviors.
*
* @fires event:formUpdated
*/
Drupal.behaviors.formUpdated = {
attach(context) {
const $context = $(context);
const contextIsForm = $context.is('form');
const $forms = (contextIsForm ? $context : $context.find('form')).once(
'form-updated',
);
let formFields;
if ($forms.length) {
// Initialize form behaviors, use $.makeArray to be able to use native
// forEach array method and have the callback parameters in the right
// order.
$.makeArray($forms).forEach((form) => {
const events = 'change.formUpdated input.formUpdated ';
const eventHandler = debounce((event) => {
triggerFormUpdated(event.target);
}, 300);
formFields = fieldsList(form).join(',');
form.setAttribute('data-drupal-form-fields', formFields);
$(form).on(events, eventHandler);
});
}
// On ajax requests context is the form element.
if (contextIsForm) {
formFields = fieldsList(context).join(',');
// @todo replace with form.getAttribute() when #1979468 is in.
const currentFields = $(context).attr('data-drupal-form-fields');
// If there has been a change in the fields or their order, trigger
// formUpdated.
if (formFields !== currentFields) {
triggerFormUpdated(context);
}
}
},
detach(context, settings, trigger) {
const $context = $(context);
const contextIsForm = $context.is('form');
if (trigger === 'unload') {
const $forms = (contextIsForm
? $context
: $context.find('form')
).removeOnce('form-updated');
if ($forms.length) {
$.makeArray($forms).forEach((form) => {
form.removeAttribute('data-drupal-form-fields');
$(form).off('.formUpdated');
});
}
}
},
};
/**
* Prepopulate form fields with information from the visitor browser.
*
* @type {Drupal~behavior}
*
* @prop {Drupal~behaviorAttach} attach
* Attaches the behavior for filling user info from browser.
*/
Drupal.behaviors.fillUserInfoFromBrowser = {
attach(context, settings) {
const userInfo = ['name', 'mail', 'homepage'];
const $forms = $('[data-user-info-from-browser]').once(
'user-info-from-browser',
);
if ($forms.length) {
userInfo.forEach((info) => {
const $element = $forms.find(`[name=${info}]`);
const browserData = localStorage.getItem(`Drupal.visitor.${info}`);
const emptyOrDefault =
$element.val() === '' ||
$element.attr('data-drupal-default-value') === $element.val();
if ($element.length && emptyOrDefault && browserData) {
$element.val(browserData);
}
});
}
$forms.on('submit', () => {
userInfo.forEach((info) => {
const $element = $forms.find(`[name=${info}]`);
if ($element.length) {
localStorage.setItem(`Drupal.visitor.${info}`, $element.val());
}
});
});
},
};
/**
* Sends a fragment interaction event on a hash change or fragment link click.
*
* @param {jQuery.Event} e
* The event triggered.
*
* @fires event:formFragmentLinkClickOrHashChange
*/
const handleFragmentLinkClickOrHashChange = (e) => {
let url;
if (e.type === 'click') {
url = e.currentTarget.location
? e.currentTarget.location
: e.currentTarget;
} else {
url = window.location;
}
const hash = url.hash.substr(1);
if (hash) {
const $target = $(`#${hash}`);
$('body').trigger('formFragmentLinkClickOrHashChange', [$target]);
/**
* Clicking a fragment link or a hash change should focus the target
* element, but event timing issues in multiple browsers require a timeout.
*/
setTimeout(() => $target.trigger('focus'), 300);
}
};
const debouncedHandleFragmentLinkClickOrHashChange = debounce(
handleFragmentLinkClickOrHashChange,
300,
true,
);
// Binds a listener to handle URL fragment changes.
$(window).on(
'hashchange.form-fragment',
debouncedHandleFragmentLinkClickOrHashChange,
);
/**
* Binds a listener to handle clicks on fragment links and absolute URL links
* containing a fragment, this is needed next to the hash change listener
* because clicking such links doesn't trigger a hash change when the fragment
* is already in the URL.
*/
$(document).on(
'click.form-fragment',
'a[href*="#"]',
debouncedHandleFragmentLinkClickOrHashChange,
);
})(jQuery, Drupal, Drupal.debounce);