// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Autocomplete wrapper for select2 library.
*
* @module core/form-autocomplete
* @copyright 2015 Damyon Wiese <damyon@moodle.com>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since 3.0
*/
define([
'jquery',
'core/log',
'core/str',
'core/templates',
'core/notification',
'core/loadingicon',
'core/aria',
'core_form/changechecker',
], function(
$,
log,
str,
templates,
notification,
LoadingIcon,
Aria,
FormChangeChecker
) {
// Private functions and variables.
/** @var {Object} KEYS - List of keycode constants. */
var KEYS = {
DOWN: 40,
ENTER: 13,
SPACE: 32,
ESCAPE: 27,
COMMA: 44,
UP: 38,
LEFT: 37,
RIGHT: 39
};
var uniqueId = Date.now();
/**
* Make an item in the selection list "active".
*
* @method activateSelection
* @private
* @param {Number} index The index in the current (visible) list of selection.
* @param {Object} state State variables for this autocomplete element.
* @return {Promise}
*/
var activateSelection = function(index, state) {
// Find the elements in the DOM.
var selectionElement = $(document.getElementById(state.selectionId));
// Count the visible items.
var length = selectionElement.children('[aria-selected=true]').length;
// Limit the index to the upper/lower bounds of the list (wrap in both directions).
index = index % length;
while (index < 0) {
index += length;
}
// Find the specified element.
var element = $(selectionElement.children('[aria-selected=true]').get(index));
// Create an id we can assign to this element.
var itemId = state.selectionId + '-' + index;
// Deselect all the selections.
selectionElement.children().attr('data-active-selection', null).attr('id', '');
// Select only this suggestion and assign it the id.
element.attr('data-active-selection', true).attr('id', itemId);
// Tell the input field it has a new active descendant so the item is announced.
selectionElement.attr('aria-activedescendant', itemId);
selectionElement.attr('data-active-value', element.attr('data-value'));
return $.Deferred().resolve();
};
/**
* Get the actively selected element from the state object.
*
* @param {Object} state
* @returns {jQuery}
*/
var getActiveElementFromState = function(state) {
var selectionRegion = $(document.getElementById(state.selectionId));
var activeId = selectionRegion.attr('aria-activedescendant');
if (activeId) {
var activeElement = $(document.getElementById(activeId));
if (activeElement.length) {
// The active descendent still exists.
return activeElement;
}
}
// Ensure we are creating a properly formed selector based on the active value.
var activeValue = selectionRegion.attr('data-active-value')?.replace(/"/g, '\\"');
return selectionRegion.find('[data-value="' + activeValue + '"]');
};
/**
* Update the active selection from the given state object.
*
* @param {Object} state
*/
var updateActiveSelectionFromState = function(state) {
var activeElement = getActiveElementFromState(state);
var activeValue = activeElement.attr('data-value');
var selectionRegion = $(document.getElementById(state.selectionId));
if (activeValue) {
// Find the index of the currently selected index.
var activeIndex = selectionRegion.find('[aria-selected=true]').index(activeElement);
if (activeIndex !== -1) {
activateSelection(activeIndex, state);
return;
}
}
// Either the active index was not set, or it could not be found.
// Select the first value instead.
activateSelection(0, state);
};
/**
* Update the element that shows the currently selected items.
*
* @method updateSelectionList
* @private
* @param {Object} options Original options for this autocomplete element.
* @param {Object} state State variables for this autocomplete element.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
* @return {Promise}
*/
var updateSelectionList = function(options, state, originalSelect) {
var pendingKey = 'form-autocomplete-updateSelectionList-' + state.inputId;
M.util.js_pending(pendingKey);
// Build up a valid context to re-render the template.
var items = [];
var newSelection = $(document.getElementById(state.selectionId));
originalSelect.children('option').each(function(index, ele) {
if ($(ele).prop('selected')) {
var label;
if ($(ele).data('html')) {
label = $(ele).data('html');
} else {
label = $(ele).html();
}
if (label !== '') {
items.push({label: label, value: $(ele).attr('value')});
}
}
});
if (!hasItemListChanged(state, items)) {
M.util.js_complete(pendingKey);
return Promise.resolve();
}
state.items = items;
var context = $.extend(options, state);
// Render the template.
return templates.render(options.templates.items, context)
.then(function(html, js) {
// Add it to the page.
templates.replaceNodeContents(newSelection, html, js);
updateActiveSelectionFromState(state);
return;
})
.then(function() {
return M.util.js_complete(pendingKey);
})
.catch(notification.exception);
};
/**
* Check whether the list of items stored in the state has changed.
*
* @param {Object} state
* @param {Array} items
* @returns {Boolean}
*/
var hasItemListChanged = function(state, items) {
if (state.items.length !== items.length) {
return true;
}
// Check for any items in the state items which are not present in the new items list.
return state.items.filter(item => items.indexOf(item) === -1).length > 0;
};
/**
* Notify of a change in the selection.
*
* @param {jQuery} originalSelect The jQuery object matching the hidden select list.
*/
var notifyChange = function(originalSelect) {
FormChangeChecker.markFormChangedFromNode(originalSelect[0]);
// Note, jQuery .change() was not working here. Better to
// use plain JavaScript anyway.
originalSelect[0].dispatchEvent(new Event('change'));
};
/**
* Remove the given item from the list of selected things.
*
* @method deselectItem
* @private
* @param {Object} options Original options for this autocomplete element.
* @param {Object} state State variables for this autocomplete element.
* @param {Element} item The item to be deselected.
* @param {Element} originalSelect The original select list.
* @return {Promise}
*/
var deselectItem = function(options, state, item, originalSelect) {
var selectedItemValue = $(item).attr('data-value');
// Look for a match, and toggle the selected property if there is a match.
originalSelect.children('option').each(function(index, ele) {
if ($(ele).attr('value') == selectedItemValue) {
$(ele).prop('selected', false);
// We remove newly created custom tags from the suggestions list when they are deselected.
if ($(ele).attr('data-iscustom')) {
$(ele).remove();
}
}
});
// Rerender the selection list.
return updateSelectionList(options, state, originalSelect)
.then(function() {
// Notify that the selection changed.
notifyChange(originalSelect);
return;
});
};
/**
* Make an item in the suggestions "active" (about to be selected).
*
* @method activateItem
* @private
* @param {Number} index The index in the current (visible) list of suggestions.
* @param {Object} state State variables for this instance of autocomplete.
* @return {Promise}
*/
var activateItem = function(index, state) {
// Find the elements in the DOM.
var inputElement = $(document.getElementById(state.inputId));
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Count the visible items.
var length = suggestionsElement.children(':not([aria-hidden])').length;
// Limit the index to the upper/lower bounds of the list (wrap in both directions).
index = index % length;
while (index < 0) {
index += length;
}
// Find the specified element.
var element = $(suggestionsElement.children(':not([aria-hidden])').get(index));
// Find the index of this item in the full list of suggestions (including hidden).
var globalIndex = $(suggestionsElement.children('[role=option]')).index(element);
// Create an id we can assign to this element.
var itemId = state.suggestionsId + '-' + globalIndex;
// Deselect all the suggestions.
suggestionsElement.children().attr('aria-selected', false).attr('id', '');
// Select only this suggestion and assign it the id.
element.attr('aria-selected', true).attr('id', itemId);
// Tell the input field it has a new active descendant so the item is announced.
inputElement.attr('aria-activedescendant', itemId);
// Scroll it into view.
var scrollPos = element.offset().top
- suggestionsElement.offset().top
+ suggestionsElement.scrollTop()
- (suggestionsElement.height() / 2);
return suggestionsElement.animate({
scrollTop: scrollPos
}, 100).promise();
};
/**
* Find the index of the current active suggestion, and activate the next one.
*
* @method activateNextItem
* @private
* @param {Object} state State variable for this auto complete element.
* @return {Promise}
*/
var activateNextItem = function(state) {
// Find the list of suggestions.
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Find the active one.
var element = suggestionsElement.children('[aria-selected=true]');
// Find it's index.
var current = suggestionsElement.children(':not([aria-hidden])').index(element);
// Activate the next one.
return activateItem(current + 1, state);
};
/**
* Find the index of the current active selection, and activate the previous one.
*
* @method activatePreviousSelection
* @private
* @param {Object} state State variables for this instance of autocomplete.
* @return {Promise}
*/
var activatePreviousSelection = function(state) {
// Find the list of selections.
var selectionsElement = $(document.getElementById(state.selectionId));
// Find the active one.
var element = selectionsElement.children('[data-active-selection]');
if (!element) {
return activateSelection(0, state);
}
// Find it's index.
var current = selectionsElement.children('[aria-selected=true]').index(element);
// Activate the next one.
return activateSelection(current - 1, state);
};
/**
* Find the index of the current active selection, and activate the next one.
*
* @method activateNextSelection
* @private
* @param {Object} state State variables for this instance of autocomplete.
* @return {Promise}
*/
var activateNextSelection = function(state) {
// Find the list of selections.
var selectionsElement = $(document.getElementById(state.selectionId));
// Find the active one.
var element = selectionsElement.children('[data-active-selection]');
var current = 0;
if (element) {
// The element was found. Determine the index and move to the next one.
current = selectionsElement.children('[aria-selected=true]').index(element);
current = current + 1;
} else {
// No selected item found. Move to the first.
current = 0;
}
return activateSelection(current, state);
};
/**
* Find the index of the current active suggestion, and activate the previous one.
*
* @method activatePreviousItem
* @private
* @param {Object} state State variables for this autocomplete element.
* @return {Promise}
*/
var activatePreviousItem = function(state) {
// Find the list of suggestions.
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Find the active one.
var element = suggestionsElement.children('[aria-selected=true]');
// Find it's index.
var current = suggestionsElement.children(':not([aria-hidden])').index(element);
// Activate the previous one.
return activateItem(current - 1, state);
};
/**
* Close the list of suggestions.
*
* @method closeSuggestions
* @private
* @param {Object} state State variables for this autocomplete element.
* @return {Promise}
*/
var closeSuggestions = function(state) {
// Find the elements in the DOM.
var inputElement = $(document.getElementById(state.inputId));
var suggestionsElement = $(document.getElementById(state.suggestionsId));
if (inputElement.attr('aria-expanded') === "true") {
// Announce the list of suggestions was closed.
inputElement.attr('aria-expanded', false);
}
// Read the current list of selections.
inputElement.attr('aria-activedescendant', state.selectionId);
// Hide the suggestions list (from screen readers too).
Aria.hide(suggestionsElement.get());
suggestionsElement.hide();
return $.Deferred().resolve();
};
/**
* Rebuild the list of suggestions based on the current values in the select list, and the query.
*
* @method updateSuggestions
* @private
* @param {Object} options The original options for this autocomplete.
* @param {Object} state The state variables for this autocomplete.
* @param {String} query The current text for the search string.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
* @return {Promise}
*/
var updateSuggestions = function(options, state, query, originalSelect) {
var pendingKey = 'form-autocomplete-updateSuggestions-' + state.inputId;
M.util.js_pending(pendingKey);
// Find the elements in the DOM.
var inputElement = $(document.getElementById(state.inputId));
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Used to track if we found any visible suggestions.
var matchingElements = false;
// Options is used by the context when rendering the suggestions from a template.
var suggestions = [];
originalSelect.children('option').each(function(index, option) {
if ($(option).prop('selected') !== true) {
suggestions[suggestions.length] = {label: option.innerHTML, value: $(option).attr('value')};
}
});
// Re-render the list of suggestions.
var searchquery = state.caseSensitive ? query : query.toLocaleLowerCase();
var context = $.extend({options: suggestions}, options, state);
var returnVal = templates.render(
'core/form_autocomplete_suggestions',
context
)
.then(function(html, js) {
// We have the new template, insert it in the page.
templates.replaceNode(suggestionsElement, html, js);
// Get the element again.
suggestionsElement = $(document.getElementById(state.suggestionsId));
// Show it if it is hidden.
Aria.unhide(suggestionsElement.get());
suggestionsElement.show();
// For each option in the list, hide it if it doesn't match the query.
suggestionsElement.children().each(function(index, node) {
node = $(node);
if ((options.caseSensitive && node.text().indexOf(searchquery) > -1) ||
(!options.caseSensitive && node.text().toLocaleLowerCase().indexOf(searchquery) > -1)) {
Aria.unhide(node.get());
node.show();
matchingElements = true;
} else {
node.hide();
Aria.hide(node.get());
}
});
// If we found any matches, show the list.
inputElement.attr('aria-expanded', true);
if (originalSelect.attr('data-notice')) {
// Display a notice rather than actual suggestions.
suggestionsElement.html(originalSelect.attr('data-notice'));
} else if (matchingElements) {
// We only activate the first item in the list if tags is false,
// because otherwise "Enter" would select the first item, instead of
// creating a new tag.
if (!options.tags) {
activateItem(0, state);
}
} else {
// Nothing matches. Tell them that.
str.get_string('nosuggestions', 'form').done(function(nosuggestionsstr) {
suggestionsElement.html(nosuggestionsstr);
});
}
return suggestionsElement;
})
.then(function() {
return M.util.js_complete(pendingKey);
})
.catch(notification.exception);
return returnVal;
};
/**
* Create a new item for the list (a tag).
*
* @method createItem
* @private
* @param {Object} options The original options for the autocomplete.
* @param {Object} state State variables for the autocomplete.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
* @return {Promise}
*/
var createItem = function(options, state, originalSelect) {
// Find the element in the DOM.
var inputElement = $(document.getElementById(state.inputId));
// Get the current text in the input field.
var query = inputElement.val();
var tags = query.split(',');
var found = false;
$.each(tags, function(tagindex, tag) {
// If we can only select one at a time, deselect any current value.
tag = tag.trim();
if (tag !== '') {
if (!options.multiple) {
originalSelect.children('option').prop('selected', false);
}
// Look for an existing option in the select list that matches this new tag.
originalSelect.children('option').each(function(index, ele) {
if ($(ele).attr('value') == tag) {
found = true;
$(ele).prop('selected', true);
}
});
// Only create the item if it's new.
if (!found) {
var option = $('<option>');
option.append(document.createTextNode(tag));
option.attr('value', tag);
originalSelect.append(option);
option.prop('selected', true);
// We mark newly created custom options as we handle them differently if they are "deselected".
option.attr('data-iscustom', true);
}
}
});
return updateSelectionList(options, state, originalSelect)
.then(function() {
// Notify that the selection changed.
notifyChange(originalSelect);
return;
})
.then(function() {
// Clear the input field.
inputElement.val('');
return;
})
.then(function() {
// Close the suggestions list.
return closeSuggestions(state);
});
};
/**
* Select the currently active item from the suggestions list.
*
* @method selectCurrentItem
* @private
* @param {Object} options The original options for the autocomplete.
* @param {Object} state State variables for the autocomplete.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
* @return {Promise}
*/
var selectCurrentItem = function(options, state, originalSelect) {
// Find the elements in the page.
var inputElement = $(document.getElementById(state.inputId));
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Here loop through suggestions and set val to join of all selected items.
var selectedItemValue = suggestionsElement.children('[aria-selected=true]').attr('data-value');
// The select will either be a single or multi select, so the following will either
// select one or more items correctly.
// Take care to use 'prop' and not 'attr' for selected properties.
// If only one can be selected at a time, start by deselecting everything.
if (!options.multiple) {
originalSelect.children('option').prop('selected', false);
}
// Look for a match, and toggle the selected property if there is a match.
originalSelect.children('option').each(function(index, ele) {
if ($(ele).attr('value') == selectedItemValue) {
$(ele).prop('selected', true);
}
});
return updateSelectionList(options, state, originalSelect)
.then(function() {
// Notify that the selection changed.
notifyChange(originalSelect);
return;
})
.then(function() {
if (options.closeSuggestionsOnSelect) {
// Clear the input element.
inputElement.val('');
// Close the list of suggestions.
return closeSuggestions(state);
} else {
// Focus on the input element so the suggestions does not auto-close.
inputElement.focus();
// Remove the last selected item from the suggestions list.
return updateSuggestions(options, state, inputElement.val(), originalSelect);
}
});
};
/**
* Fetch a new list of options via ajax.
*
* @method updateAjax
* @private
* @param {Event} e The event that triggered this update.
* @param {Object} options The original options for the autocomplete.
* @param {Object} state The state variables for the autocomplete.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
* @param {Object} ajaxHandler This is a module that does the ajax fetch and translates the results.
* @return {Promise}
*/
var updateAjax = function(e, options, state, originalSelect, ajaxHandler) {
var pendingPromise = addPendingJSPromise('updateAjax');
// We need to show the indicator outside of the hidden select list.
// So we get the parent id of the hidden select list.
var parentElement = $(document.getElementById(state.selectId)).parent();
LoadingIcon.addIconToContainerRemoveOnCompletion(parentElement, pendingPromise);
// Get the query to pass to the ajax function.
var query = $(e.currentTarget).val();
// Call the transport function to do the ajax (name taken from Select2).
ajaxHandler.transport(options.selector, query, function(results) {
// We got a result - pass it through the translator before using it.
var processedResults = ajaxHandler.processResults(options.selector, results);
var existingValues = [];
// Now destroy all options that are not currently selected.
if (!options.multiple) {
originalSelect.children('option').remove();
}
originalSelect.children('option').each(function(optionIndex, option) {
option = $(option);
if (!option.prop('selected')) {
option.remove();
} else {
existingValues.push(String(option.attr('value')));
}
});
if (!options.multiple && originalSelect.children('option').length === 0) {
// If this is a single select - and there are no current options
// the first option added will be selected by the browser. This causes a bug!
// We need to insert an empty option so that none of the real options are selected.
var option = $('<option>');
originalSelect.append(option);
}
if ($.isArray(processedResults)) {
// Add all the new ones returned from ajax.
$.each(processedResults, function(resultIndex, result) {
if (existingValues.indexOf(String(result.value)) === -1) {
var option = $('<option>');
option.append(result.label);
option.attr('value', result.value);
originalSelect.append(option);
}
});
originalSelect.attr('data-notice', '');
} else {
// The AJAX handler returned a string instead of the array.
originalSelect.attr('data-notice', processedResults);
}
// Update the list of suggestions now from the new values in the select list.
pendingPromise.resolve(updateSuggestions(options, state, '', originalSelect));
}, function(error) {
pendingPromise.reject(error);
});
return pendingPromise;
};
/**
* Add all the event listeners required for keyboard nav, blur clicks etc.
*
* @method addNavigation
* @private
* @param {Object} options The options used to create this autocomplete element.
* @param {Object} state State variables for this autocomplete element.
* @param {JQuery} originalSelect The JQuery object matching the hidden select list.
*/
var addNavigation = function(options, state, originalSelect) {
// Start with the input element.
var inputElement = $(document.getElementById(state.inputId));
// Add keyboard nav with keydown.
inputElement.on('keydown', function(e) {
var pendingJsPromise = addPendingJSPromise('addNavigation-' + state.inputId + '-' + e.keyCode);
switch (e.keyCode) {
case KEYS.DOWN:
// If the suggestion list is open, move to the next item.
if (!options.showSuggestions) {
// Do not consume this event.
pendingJsPromise.resolve();
return true;
} else if (inputElement.attr('aria-expanded') === "true") {
pendingJsPromise.resolve(activateNextItem(state));
} else {
// Handle ajax population of suggestions.
if (!inputElement.val() && options.ajax) {
require([options.ajax], function(ajaxHandler) {
pendingJsPromise.resolve(updateAjax(e, options, state, originalSelect, ajaxHandler));
});
} else {
// Open the suggestions list.
pendingJsPromise.resolve(updateSuggestions(options, state, inputElement.val(), originalSelect));
}
}
// We handled this event, so prevent it.
e.preventDefault();
return false;
case KEYS.UP:
// Choose the previous active item.
pendingJsPromise.resolve(activatePreviousItem(state));
// We handled this event, so prevent it.
e.preventDefault();
return false;
case KEYS.ENTER:
var suggestionsElement = $(document.getElementById(state.suggestionsId));
if ((inputElement.attr('aria-expanded') === "true") &&
(suggestionsElement.children('[aria-selected=true]').length > 0)) {
// If the suggestion list has an active item, select it.
pendingJsPromise.resolve(selectCurrentItem(options, state, originalSelect));
} else if (options.tags) {
// If tags are enabled, create a tag.
pendingJsPromise.resolve(createItem(options, state, originalSelect));
} else {
pendingJsPromise.resolve();
}
// We handled this event, so prevent it.
e.preventDefault();
return false;
case KEYS.ESCAPE:
if (inputElement.attr('aria-expanded') === "true") {
// If the suggestion list is open, close it.
pendingJsPromise.resolve(closeSuggestions(state));
} else {
pendingJsPromise.resolve();
}
// We handled this event, so prevent it.
e.preventDefault();
return false;
}
pendingJsPromise.resolve();
return true;
});
// Support multi lingual COMMA keycode (44).
inputElement.on('keypress', function(e) {
if (e.keyCode === KEYS.COMMA) {
if (options.tags) {
// If we are allowing tags, comma should create a tag (or enter).
addPendingJSPromise('keypress-' + e.keyCode)
.resolve(createItem(options, state, originalSelect));
}
// We handled this event, so prevent it.
e.preventDefault();
return false;
}
return true;
});
// Support submitting the form without leaving the autocomplete element,
// or submitting too quick before the blur handler action is completed.
inputElement.closest('form').on('submit', function() {
if (options.tags) {
// If tags are enabled, create a tag.
addPendingJSPromise('form-autocomplete-submit')
.resolve(createItem(options, state, originalSelect));
}
return true;
});
inputElement.on('blur', function() {
var pendingPromise = addPendingJSPromise('form-autocomplete-blur');
window.setTimeout(function() {
// Get the current element with focus.
var focusElement = $(document.activeElement);
var timeoutPromise = $.Deferred();
// Only close the menu if the input hasn't regained focus and if the element still exists,
// and regain focus if the scrollbar is clicked.
// Due to the half a second delay, it is possible that the input element no longer exist
// by the time this code is being executed.
if (focusElement.is(document.getElementById(state.suggestionsId))) {
inputElement.focus(); // Probably the scrollbar is clicked. Regain focus.
} else if (!focusElement.is(inputElement) && $(document.getElementById(state.inputId)).length) {
if (options.tags) {
timeoutPromise.then(function() {
return createItem(options, state, originalSelect);
})
.catch();
}
timeoutPromise.then(function() {
return closeSuggestions(state);
})
.catch();
}
timeoutPromise.then(function() {
return pendingPromise.resolve();
})
.catch();
timeoutPromise.resolve();
}, 500);
});
if (options.showSuggestions) {
var arrowElement = $(document.getElementById(state.downArrowId));
arrowElement.on('click', function(e) {
var pendingPromise = addPendingJSPromise('form-autocomplete-show-suggestions');
// Prevent the close timer, or we will open, then close the suggestions.
inputElement.focus();
// Handle ajax population of suggestions.
if (!inputElement.val() && options.ajax) {
require([options.ajax], function(ajaxHandler) {
pendingPromise.resolve(updateAjax(e, options, state, originalSelect, ajaxHandler));
});
} else {
// Else - open the suggestions list.
pendingPromise.resolve(updateSuggestions(options, state, inputElement.val(), originalSelect));
}
});
}
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Remove any click handler first.
suggestionsElement.parent().prop("onclick", null).off("click");
suggestionsElement.parent().on('click', `#${state.suggestionsId} [role=option]`, function(e) {
var pendingPromise = addPendingJSPromise('form-autocomplete-parent');
// Handle clicks on suggestions.
var element = $(e.currentTarget).closest('[role=option]');
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Find the index of the clicked on suggestion.
var current = suggestionsElement.children(':not([aria-hidden])').index(element);
// Activate it.
activateItem(current, state)
.then(function() {
// And select it.
return selectCurrentItem(options, state, originalSelect);
})
.then(function() {
return pendingPromise.resolve();
})
.catch();
});
var selectionElement = $(document.getElementById(state.selectionId));
// Handle clicks on the selected items (will unselect an item).
selectionElement.on('click', '[role=option]', function(e) {
var pendingPromise = addPendingJSPromise('form-autocomplete-clicks');
// Remove it from the selection.
pendingPromise.resolve(deselectItem(options, state, $(e.currentTarget), originalSelect));
});
// When listbox is focused, focus on the first option if there is no focused option.
selectionElement.on('focus', function() {
updateActiveSelectionFromState(state);
});
// Keyboard navigation for the selection list.
selectionElement.on('keydown', function(e) {
var pendingPromise = addPendingJSPromise('form-autocomplete-keydown-' + e.keyCode);
switch (e.keyCode) {
case KEYS.RIGHT:
case KEYS.DOWN:
// We handled this event, so prevent it.
e.preventDefault();
// Choose the next selection item.
pendingPromise.resolve(activateNextSelection(state));
return;
case KEYS.LEFT:
case KEYS.UP:
// We handled this event, so prevent it.
e.preventDefault();
// Choose the previous selection item.
pendingPromise.resolve(activatePreviousSelection(state));
return;
case KEYS.SPACE:
case KEYS.ENTER:
// Get the item that is currently selected.
var selectedItem = $(document.getElementById(state.selectionId)).children('[data-active-selection]');
if (selectedItem) {
e.preventDefault();
// Unselect this item.
pendingPromise.resolve(deselectItem(options, state, selectedItem, originalSelect));
}
return;
}
// Not handled. Resolve the promise.
pendingPromise.resolve();
});
// Whenever the input field changes, update the suggestion list.
if (options.showSuggestions) {
// Store the value of the field as its last value, when the field gains focus.
inputElement.on('focus', function(e) {
var query = $(e.currentTarget).val();
$(e.currentTarget).data('last-value', query);
});
// If this field uses ajax, set it up.
if (options.ajax) {
require([options.ajax], function(ajaxHandler) {
// Creating throttled handlers free of race conditions, and accurate.
// This code keeps track of a throttleTimeout, which is periodically polled.
// Once the throttled function is executed, the fact that it is running is noted.
// If a subsequent request comes in whilst it is running, this request is re-applied.
var throttleTimeout = null;
var inProgress = false;
var pendingKey = 'autocomplete-throttledhandler';
var handler = function(e) {
// Empty the current timeout.
throttleTimeout = null;
// Mark this request as in-progress.
inProgress = true;
// Process the request.
updateAjax(e, options, state, originalSelect, ajaxHandler)
.then(function() {
// Check if the throttleTimeout is still empty.
// There's a potential condition whereby the JS request takes long enough to complete that
// another task has been queued.
// In this case another task will be kicked off and we must wait for that before marking htis as
// complete.
if (null === throttleTimeout) {
// Mark this task as complete.
M.util.js_complete(pendingKey);
}
inProgress = false;
return arguments[0];
})
.catch(notification.exception);
};
// For input events, we do not want to trigger many, many updates.
var throttledHandler = function(e) {
window.clearTimeout(throttleTimeout);
if (inProgress) {
// A request is currently ongoing.
// Delay this request another 100ms.
throttleTimeout = window.setTimeout(throttledHandler.bind(this, e), 100);
return;
}
if (throttleTimeout === null) {
// There is currently no existing timeout handler, and it has not been recently cleared, so
// this is the start of a throttling check.
M.util.js_pending(pendingKey);
}
// There is currently no existing timeout handler, and it has not been recently cleared, so this
// is the start of a throttling check.
// Queue a call to the handler.
throttleTimeout = window.setTimeout(handler.bind(this, e), 300);
};
// Trigger an ajax update after the text field value changes.
inputElement.on('input', function(e) {
var query = $(e.currentTarget).val();
var last = $(e.currentTarget).data('last-value');
// IE11 fires many more input events than required - even when the value has not changed.
if (last !== query) {
throttledHandler(e);
}
$(e.currentTarget).data('last-value', query);
});
});
} else {
inputElement.on('input', function(e) {
var query = $(e.currentTarget).val();
var last = $(e.currentTarget).data('last-value');
// IE11 fires many more input events than required - even when the value has not changed.
// We need to only do this for real value changed events or the suggestions will be
// unclickable on IE11 (because they will be rebuilt before the click event fires).
// Note - because of this we cannot close the list when the query is empty or it will break
// on IE11.
if (last !== query) {
updateSuggestions(options, state, query, originalSelect);
}
$(e.currentTarget).data('last-value', query);
});
}
}
};
/**
* Create and return an unresolved Promise for some pending JS.
*
* @param {String} key The unique identifier for this promise
* @return {Promise}
*/
var addPendingJSPromise = function(key) {
var pendingKey = 'form-autocomplete:' + key;
M.util.js_pending(pendingKey);
var pendingPromise = $.Deferred();
pendingPromise
.then(function() {
M.util.js_complete(pendingKey);
return arguments[0];
})
.catch(notification.exception);
return pendingPromise;
};
return {
// Public variables and functions.
/**
* Turn a boring select box into an auto-complete beast.
*
* @method enhance
* @param {string} selector The selector that identifies the select box.
* @param {boolean} tags Whether to allow support for tags (can define new entries).
* @param {string} ajax Name of an AMD module to handle ajax requests. If specified, the AMD
* module must expose 2 functions "transport" and "processResults".
* These are modeled on Select2 see: https://select2.github.io/options.html#ajax
* @param {String} placeholder - The text to display before a selection is made.
* @param {Boolean} caseSensitive - If search has to be made case sensitive.
* @param {Boolean} showSuggestions - If suggestions should be shown
* @param {String} noSelectionString - Text to display when there is no selection
* @param {Boolean} closeSuggestionsOnSelect - Whether to close the suggestions immediately after making a selection.
* @param {Object} templateOverrides A set of templates to use instead of the standard templates
* @return {Promise}
*/
enhance: function(selector, tags, ajax, placeholder, caseSensitive, showSuggestions, noSelectionString,
closeSuggestionsOnSelect, templateOverrides) {
// Set some default values.
var options = {
selector: selector,
tags: false,
ajax: false,
placeholder: placeholder,
caseSensitive: false,
showSuggestions: true,
noSelectionString: noSelectionString,
templates: $.extend({
input: 'core/form_autocomplete_input',
items: 'core/form_autocomplete_selection_items',
layout: 'core/form_autocomplete_layout',
selection: 'core/form_autocomplete_selection',
suggestions: 'core/form_autocomplete_suggestions',
}, templateOverrides),
};
var pendingKey = 'autocomplete-setup-' + selector;
M.util.js_pending(pendingKey);
if (typeof tags !== "undefined") {
options.tags = tags;
}
if (typeof ajax !== "undefined") {
options.ajax = ajax;
}
if (typeof caseSensitive !== "undefined") {
options.caseSensitive = caseSensitive;
}
if (typeof showSuggestions !== "undefined") {
options.showSuggestions = showSuggestions;
}
if (typeof noSelectionString === "undefined") {
str.get_string('noselection', 'form').done(function(result) {
options.noSelectionString = result;
}).fail(notification.exception);
}
// Look for the select element.
var originalSelect = $(selector);
if (!originalSelect) {
log.debug('Selector not found: ' + selector);
M.util.js_complete(pendingKey);
return false;
}
// Ensure we enhance the element only once.
if (originalSelect.data('enhanced') === 'enhanced') {
M.util.js_complete(pendingKey);
return false;
}
originalSelect.data('enhanced', 'enhanced');
// Hide the original select.
Aria.hide(originalSelect.get());
originalSelect.css('visibility', 'hidden');
// Find or generate some ids.
var state = {
selectId: originalSelect.attr('id'),
inputId: 'form_autocomplete_input-' + uniqueId,
suggestionsId: 'form_autocomplete_suggestions-' + uniqueId,
selectionId: 'form_autocomplete_selection-' + uniqueId,
downArrowId: 'form_autocomplete_downarrow-' + uniqueId,
items: [],
};
// Increment the unique counter so we don't get duplicates ever.
uniqueId++;
options.multiple = originalSelect.attr('multiple');
if (!options.multiple) {
// If this is a single select then there is no way to de-select the current value -
// unless we add a bogus blank option to be selected when nothing else is.
// This matches similar code in updateAjax above.
originalSelect.prepend('<option>');
}
if (typeof closeSuggestionsOnSelect !== "undefined") {
options.closeSuggestionsOnSelect = closeSuggestionsOnSelect;
} else {
// If not specified, this will close suggestions by default for single-select elements only.
options.closeSuggestionsOnSelect = !options.multiple;
}
var originalLabel = $('[for=' + state.selectId + ']');
// Create the new markup and insert it after the select.
var suggestions = [];
originalSelect.children('option').each(function(index, option) {
suggestions[index] = {label: option.innerHTML, value: $(option).attr('value')};
});
// Render all the parts of our UI.
var context = $.extend({}, options, state);
context.options = suggestions;
context.items = [];
// Collect rendered inline JS to be executed once the HTML is shown.
var collectedjs = '';
var renderLayout = templates.render(options.templates.layout, {})
.then(function(html) {
return $(html);
});
var renderInput = templates.render(options.templates.input, context).then(function(html, js) {
collectedjs += js;
return $(html);
});
var renderDatalist = templates.render(options.templates.suggestions, context).then(function(html, js) {
collectedjs += js;
return $(html);
});
var renderSelection = templates.render(options.templates.selection, context).then(function(html, js) {
collectedjs += js;
return $(html);
});
return $.when(renderLayout, renderInput, renderDatalist, renderSelection)
.then(function(layout, input, suggestions, selection) {
originalSelect.hide();
var container = originalSelect.parent();
// Ensure that the data-fieldtype is set for behat.
input.find('input').attr('data-fieldtype', 'autocomplete');
container.append(layout);
container.find('[data-region="form_autocomplete-input"]').replaceWith(input);
container.find('[data-region="form_autocomplete-suggestions"]').replaceWith(suggestions);
container.find('[data-region="form_autocomplete-selection"]').replaceWith(selection);
templates.runTemplateJS(collectedjs);
// Update the form label to point to the text input.
originalLabel.attr('for', state.inputId);
// Add the event handlers.
addNavigation(options, state, originalSelect);
var suggestionsElement = $(document.getElementById(state.suggestionsId));
// Hide the suggestions by default.
suggestionsElement.hide();
Aria.hide(suggestionsElement.get());
return;
})
.then(function() {
// Show the current values in the selection list.
return updateSelectionList(options, state, originalSelect);
})
.then(function() {
return M.util.js_complete(pendingKey);
})
.catch(function(error) {
M.util.js_complete(pendingKey);
notification.exception(error);
});
}
};
});