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feat: replace HTML validation attrs with soft validation
We mustn't prevent form submission, but we still want to give some feedback to the user. Closes #57
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‎amd/build/view_question.min.js

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‎amd/build/view_question.min.js.map

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‎amd/src/view_question.js

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Original file line numberDiff line numberDiff line change
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/*
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* This file is part of the QuestionPy Moodle plugin - https://questionpy.org
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*
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* Moodle is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Moodle is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Moodle. If not, see <http://www.gnu.org/licenses/>.
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*/
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import $ from "jquery";
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import "theme_boost/bootstrap/popover";
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import {get_string as getString} from "core/str";
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/**
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* If the given input(-like) element is labelled, returns the label element. Returns null otherwise.
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*
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* @param {HTMLElement} input
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* @return {HTMLLabelElement | null}
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* @see {@link https://html.spec.whatwg.org/multipage/forms.html#the-label-element}
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*/
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function getLabelFor(input) {
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// A label can reference its labeled control in its for attribute.
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const id = input.id;
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if (id !== "") {
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const label = document.querySelector(`label[for='${id}']`);
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if (label) {
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return label;
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}
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}
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// Or the labeled control can be a descendant of the label.
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const label = input.closest("label");
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if (label) {
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return label;
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}
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return null;
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}
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/**
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* Marks the given input element as invalid.
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*
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* @param {HTMLElement} element
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* @param {string} message validation message to show
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* @param {boolean} ariaInvalid
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*/
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function markInvalid(element, message, ariaInvalid = true) {
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element.classList.add("is-invalid");
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if (ariaInvalid) {
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element.setAttribute("aria-invalid", "true");
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} else {
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element.removeAttribute("aria-invalid");
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}
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let popoverTarget = element;
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if (element.type === "checkbox" || element.type === "radio") {
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// Checkboxes and radios make for a very small hit area for the popover, so we attach the popover to the label.
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const label = getLabelFor(element);
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if (!label) {
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// No label -> Add the popover just to the checkbox.
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popoverTarget = element;
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} else if (label.contains(element)) {
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// Label contains checkbox -> Add the popover just to the label.
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popoverTarget = label;
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} else {
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// Separate label and checkbox -> Add the popover to both.
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popoverTarget = [element, label];
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}
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}
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$(popoverTarget).popover({
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toggle: "popover",
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trigger: "hover",
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content: message
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});
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}
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/**
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* Undoes what {@link markInvalid} did.
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*
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* @param {HTMLInputElement} element
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*/
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function unmarkInvalid(element) {
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element.classList.remove("is-invalid");
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element.removeAttribute("aria-invalid");
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$([element, getLabelFor(element)]).popover("dispose");
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}
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/**
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* Softly (i.e. without preventing form submission) validates constraints on the given element.
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*
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* @param {HTMLInputElement} element
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*/
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async function checkConditions(element) {
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if (element.dataset.qpy_required !== undefined) {
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let isPresent;
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if (element.type === "checkbox" || element.type === "radio") {
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isPresent = element.checked;
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} else {
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isPresent = element.value !== null && element.value !== "";
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}
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if (!isPresent) {
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const message = await getString("input_missing", "qtype_questionpy");
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// Aria-invalid shouldn't be set for missing inputs until the user has tried to submit them.
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// https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-invalid
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markInvalid(element, message, false);
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return;
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}
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}
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const pattern = element.dataset.qpy_pattern;
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if (pattern !== undefined && element.value !== null && element.value !== ""
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&& !element.value.match(`^(?:${pattern})$`)) {
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const message = await getString("input_invalid", "qtype_questionpy");
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markInvalid(element, message);
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return;
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}
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const minLength = element.dataset.qpy_minlength;
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if (minLength !== undefined && element.value !== null && element.value !== ""
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&& element.value.length < parseInt(minLength)) {
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const message = await getString("input_too_short", "qtype_questionpy", minLength);
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markInvalid(element, message);
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return;
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}
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const maxLength = element.dataset.qpy_maxlength;
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if (maxLength !== undefined && element.value !== null && element.value !== ""
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&& element.value.length > parseInt(maxLength)) {
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const message = await getString("input_too_long", "qtype_questionpy", maxLength);
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markInvalid(element, message);
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return;
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}
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unmarkInvalid(element);
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}
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/**
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* Adds change event handlers for soft validation.
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*/
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export async function init() {
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for (const element of document
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.querySelectorAll("[data-qpy_required], [data-qpy_pattern], [data-qpy_minlength], [data-qpy_maxlength]")) {
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await checkConditions(element);
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element.addEventListener("change", event => checkConditions(event.target));
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}
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}

‎classes/question_metadata.php

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@@ -38,15 +38,25 @@ class question_metadata {
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*/
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public array $expecteddata = [];
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/**
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* @var string[] an array of required field names
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* @see \question_manually_gradable::is_complete_response()
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* @see \question_manually_gradable::is_gradable_response()
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*/
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public array $requiredfields = [];
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/**
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* Initializes a new instance.
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*
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* @param array|null $correctresponse if known, an array of `name => correct_value` entries for the expected
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* response fields
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* @param array $expecteddata an array of `name => PARAM_X` entries for the expected response fields
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* @param string[] $requiredfields an array of required field names
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*/
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public function __construct(?array $correctresponse = null, array $expecteddata = []) {
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public function __construct(?array $correctresponse = null, array $expecteddata = [],
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array $requiredfields = []) {
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$this->correctresponse = $correctresponse;
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$this->expecteddata = $expecteddata;
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$this->requiredfields = $requiredfields;
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}
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}

‎classes/question_ui_renderer.php

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@@ -182,6 +182,10 @@ public function get_metadata(): question_metadata {
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$name = $element->getAttribute("name");
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if ($name) {
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$this->metadata->expecteddata[$name] = PARAM_RAW;
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if ($element->hasAttribute("required")) {
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$this->metadata->requiredfields[] = $name;
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}
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}
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}
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}
@@ -215,6 +219,7 @@ private function render_part(DOMNode $part, question_attempt $qa, ?question_disp
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try {
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$this->hide_unwanted_feedback($xpath, $options);
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$this->set_input_values_and_readonly($xpath, $qa, $options);
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$this->soften_validation($xpath);
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$this->shuffle_contents($xpath);
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$this->add_styles($xpath);
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$this->mangle_ids_and_names($xpath, $qa);
@@ -451,6 +456,44 @@ private function resolve_placeholders(DOMXPath $xpath): void {
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}
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}
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/**
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* Replaces the HTML attributes `pattern`, `required`, `minlength`, `maxlength` so that submission is not prevented.
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*
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* The standard attributes are replaced with `data-qpy_X`, which are then evaluated in JS.
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* Ideally we'd also want to handle min and max here, but their evaluation in JS would be quite complicated.
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*
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* @param DOMXPath $xpath
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* @return void
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*/
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private function soften_validation(DOMXPath $xpath): void {
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/** @var DOMElement $element */
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foreach ($xpath->query("//xhtml:input[@pattern]") as $element) {
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$pattern = $element->getAttribute("pattern");
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$element->removeAttribute("pattern");
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$element->setAttribute("data-qpy_pattern", $pattern);
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}
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foreach ($xpath->query("(//xhtml:input | //xhtml:select | //xhtml:textarea)[@required]") as $element) {
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$element->removeAttribute("required");
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$element->setAttribute("data-qpy_required", "data-qpy_required");
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$element->setAttribute("aria-required", "true");
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}
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foreach ($xpath->query("(//xhtml:input | //xhtml:textarea)[@minlength or @maxlength]") as $element) {
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$minlength = $element->getAttribute("minlength");
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if ($minlength !== "") {
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$element->removeAttribute("minlength");
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$element->setAttribute("data-qpy_minlength", $minlength);
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}
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$maxlength = $element->getAttribute("maxlength");
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if ($maxlength !== "") {
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$element->removeAttribute("maxlength");
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$element->setAttribute("data-qpy_maxlength", $maxlength);
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}
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}
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}
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/**
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* Adds CSS classes to various elements to style them similarly to Moodle's own question types.
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*

‎lang/en/qtype_questionpy.php

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// Question management.
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$string['package_not_found'] = 'The requested package {$a->packagehash} does not exist.';
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// Question UI.
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$string['input_missing'] = 'This field is required.';
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$string['input_invalid'] = 'Invalid input.';
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$string['input_too_long'] = 'Please enter at most {$a} characters.';
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$string['input_too_short'] = 'Please enter at least {$a} characters.';
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// Connector.
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$string['curl_init_error'] = 'Could not initialize cURL. Error number: {$a}';
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$string['curl_exec_error'] = 'Error while fetching from server. Error number: {$a}';

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