I have been having issues with a fetch request in my Stimulus controller. Whenever we try to send a fetch request we get a network error “Load failed” error.
The fetch request is supposed to send answers to questions from the front end to the back end and everything was working fine until we started testing it in Safari on iPhones in production. I have also tried using axios which yielded the same result. This does not happeen on all iPhones only on some devices (trying to collect data regarding software versions etc.). All works fine on laptops/desktops, Android devices and in other browsers on iPhones.
Please see my full Stimulus controller below.
import { Controller } from "@hotwired/stimulus"
export default class extends Controller {
static get targets() {
return ["question", "submit", "next", "back", "source", "preview", "error", "loading"];
}
static get values() {
return { responseDetailsPath: String };
}
initialize() {
console.log("Questionnaire controller initialized test for 24/06/2024")
this.showCurrentQuestion(0);
this.lastSelectedImages = {};
this.hasUnsavedChanges = false;
this.initInputListeners();
}
initInputListeners() {
this.questionTargets.forEach((question) => {
const inputs = question.querySelectorAll("input, select, textarea");
inputs.forEach((input) => {
input.addEventListener("change", () => {
this.hasUnsavedChanges = true;
});
});
});
}
displayLoadingAnimation(show) {
if (show) {
this.loadingTarget.classList.remove("d-none");
} else {
this.loadingTarget.classList.add("d-none");
}
}
async next() {
if (!this.validateResponse()) {
return;
}
if (this.hasUnsavedChanges) {
this.displayLoadingAnimation(true);
try {
await this.sendResponse();
} catch (error) {
this.displayLoadingAnimation(false);
return;
}
}
const currentIndex = this.currentQuestionIndex();
if (currentIndex < this.questionTargets.length - 1) {
this.showCurrentQuestion(currentIndex + 1);
}
this.updateButtonVisibility();
}
async previous() {
const currentIndex = this.currentQuestionIndex();
if (!this.validateResponse()) {
if (currentIndex > 0) {
this.showCurrentQuestion(currentIndex - 1);
}
this.updateButtonVisibility();
return;
}
if (this.hasUnsavedChanges) {
this.displayLoadingAnimation(true);
try {
await this.sendResponse();
} catch (error) {
this.displayLoadingAnimation(false);
return;
}
}
if (currentIndex > 0) {
this.showCurrentQuestion(currentIndex - 1);
}
this.updateButtonVisibility();
}
updateButtonVisibility() {
const currentIndex = this.currentQuestionIndex();
this.backTarget.classList.toggle("d-none", currentIndex === 0);
this.nextTarget.classList.toggle("d-none", currentIndex === this.questionTargets.length - 1);
this.submitTarget.classList.toggle("d-none", currentIndex !== this.questionTargets.length - 1);
}
validateResponse() {
const currentIndex = this.currentQuestionIndex();
const currentQuestion = this.questionTargets[currentIndex];
const input = currentQuestion.querySelector("input, select, textarea");
const isRequired = input.required;
const inputType = input.getAttribute("type");
let isValid;
if (inputType !== "file") {
isValid = input.value.trim() !== "";
} else {
const fileSelected = input.files.length > 0;
const existingImage = currentQuestion.dataset.existingImage && currentQuestion.dataset.existingImage.trim() !== "";
const lastSelectedImage = this.lastSelectedImages[currentQuestion.dataset.itemQuestionId];
isValid = fileSelected || existingImage || this.lastSelectedImages[currentQuestion.dataset.itemQuestionId];
}
const errorMessageDiv = this.errorTargets[currentIndex];
if (!isValid && isRequired) {
errorMessageDiv.style.display = "block";
errorMessageDiv.textContent = "Пожалуйста, дайте ответ на текущий вопрос.";
return false
} else {
errorMessageDiv.style.display = "none";
return true
}
}
showCurrentQuestion(index) {
this.questionTargets.forEach((element, i) => {
element.classList.toggle("d-none", i !== index);
const errorMessageDiv = this.errorTargets[i];
if (errorMessageDiv) {
errorMessageDiv.style.display = "none";
}
if (i === index && element.dataset.existingImage) {
this.updateImagePreview(element);
}
});
this.hasUnsavedChanges = false;
}
updateImagePreview(questionElement) {
const existingImageUrl = questionElement.dataset.existingImage;
const previewTarget = questionElement.querySelector("[data-questionnaire-target='preview");
if (existingImageUrl) {
previewTarget.innerHTML = `<img src="${existingImageUrl}">`;
} else {
previewTarget.innerHTML = '';
}
}
currentQuestionIndex() {
return this.questionTargets.findIndex((element) => !element.classList.contains("d-none"));
}
async show(event) {
const index = this.sourceTargets.indexOf(event.target);
const previewTarget = this.previewTargets[index];
const file = event.target.files[0];
const currentIndex = this.currentQuestionIndex();
const currentQuestion = this.questionTargets[currentIndex];
if (file && file.type.match('image')) {
try {
const resizedFile = await this.resizeImage(file);
const reader = new FileReader();
reader.onload = function(e) {
previewTarget.innerHTML = `<img src="${e.target.result}">`
};
reader.readAsDataURL(resizedFile);
this.lastSelectedImages[currentQuestion.dataset.itemQuestionId] = resizedFile;
this.hasUnsavedChanges = true;
} catch (error) {
console.error("Error resizing image:", error);
}
}
}
async submit(event) {
event.preventDefault();
if (!this.validateResponse()) {
return;
}
this.displayLoadingAnimation(true);
try {
const isFinal = true;
await this.sendResponse(isFinal);
window.location.href = "/success";
} catch (error) {
this.displayLoadingAnimation(false);
}
}
async sendResponse(isFinal = false) {
const currentIndex = this.currentQuestionIndex();
const currentQuestion = this.questionTargets[currentIndex];
const input = currentQuestion.querySelector("input, select, textarea");
const name = input.name;
const value = input.value;
let payload = {
question_id: currentQuestion.dataset.itemQuestionId,
hardware_id: currentQuestion.dataset.itemHardwareId,
questionnaire_id: currentQuestion.dataset.itemQuestionnaireId,
answer: value,
};
if (isFinal) {
payload.is_final = true;
}
if (input.type === "file") {
let file = input.files[0];
if (file) {
try {
file = await this.resizeImage(file);
payload.answer = await this.fileToBase64(file);
} catch (error) {
console.error("Error resizing or converting image:", error);
}
} else if (this.lastSelectedImages[currentQuestion.dataset.itemQuestionId]) {
payload.answer = await this.fileToBase64(this.lastSelectedImages[currentQuestion.dataset.itemQuestionId]);
this.lastSelectedImages[currentQuestion.dataset.itemQuestionId] = null;
} else if (currentQuestion.dataset.existingImage) {
payload.keep_existing_image = true;
}
}
try {
const response = await fetch(this.responseDetailsPathValue, {
method: 'POST',
headers: {
'Content-Type': 'application/json',
'X-CSRF-Token': document.querySelector("[name='csrf-token']").content,
},
body: JSON.stringify(payload),
});
if (!response.ok) {
const errorData = await response.json();
throw new Error(errorData.error || `HTTP Status ${response.status}`);
}
this.hasUnsavedChanges = false;
return response;
} catch (error) {
console.error("Error sending response:", error);
this.displayErrorMessage(currentQuestion, error.message);
throw error;
} finally {
this.displayLoadingAnimation(false);
}
}
fileToBase64(file) {
return new Promise((resolve, reject) => {
const reader = new FileReader();
reader.onload = function (e) {
resolve(e.target.result);
};
reader.onerror = function (error) {
reject(error);
};
reader.readAsDataURL(file);
});
}
displayErrorMessage(questionElement, message) {
const errorMessageDiv = questionElement.querySelector("[data-questionnaire-target='error']");
if (errorMessageDiv) {
errorMessageDiv.style.display = "block";
errorMessageDiv.textContent = message;
}
}
findQuestionIndex(input) {
let parentQuestion = input.closest("[data-questionnaire-target='question']");
return this.questionTargets.indexOf(parentQuestion);
}
resizeImage(file, maxWidth = 1024, maxHeight = 1024, quality = 1) {
return new Promise((resolve, reject) => {
const img = document.createElement("img");
const reader = new FileReader();
reader.onload = function(e) {
img.src = e.target.result;
img.onload = function() {
let width = img.width;
let height = img.height;
if (width > height) {
if (width > maxWidth) {
height *= maxWidth / width;
width = maxWidth;
}
} else {
if (height > maxHeight) {
width *= maxHeight / height;
height = maxHeight;
}
}
const canvas = document.createElement("canvas");
canvas.width = width;
canvas.height = height;
const ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0, width, height);
canvas.toBlob((blob) => {
resolve(new File([blob], file.name, { type: file.type, lastModified: Date.now() }));
}, file.type, quality);
};
img.onerror = function(err) {
reject(err);
};
};
reader.onerror = function(err) {
reject(err);
};
reader.readAsDataURL(file);
});
}
}
P.S. if some things in the code, such as the way I have written my static declarations or the fact that I am conveerting images to base64 strings, seem strange, these aree just my multiple attempts of fixing the issue. Please ignore those issues as I initially had a very simple fetch request written and was getting the same error. I specifically want some help in figuring out what exactly could be causing the issue so that I can atteempt to fix it.
Thanks a lot for your help!
