Increase cache duration to 24 hours and implement local storage caching for Pokémon data with lazy loading for images

v2/get-pokemon.php

@@ -10,7 +10,7 @@ if ($conn->connect_error) {
     die("Connection failed: " . $conn->connect_error);
 }
 
-header("Cache-Control: max-age=3600"); // Cache for 1 hour
+header("Cache-Control: max-age=86400"); // Cache for 24 hours
 
 if (isset($_GET['id'])) {
     $id = intval($_GET['id']);

v2/pokemon.js

@@ -1,4 +1,5 @@
 const MAX_POKEMON = 151;
+const CACHE_DURATION = 24 * 60 * 60 * 1000; // 24 hours in milliseconds
 const listWrapper = document.querySelector(".list-wrapper");
 const searchInput = document.querySelector("#search-input");
 const numberFilter = document.querySelector("#number");
@@ -7,23 +8,42 @@ const notFoundMessage = document.querySelector("#not-found-message");
 
 let allPokemons = [];
 
-fetch(`./get-pokemon.php`)
-  .then((response) => response.json())
-  .then((data) => {
-    if (Array.isArray(data)) {
-      allPokemons = data;
-      cacheImages(allPokemons);
-      displayPokemons(allPokemons);
-    } else {
-      console.error("Unexpected response format:", data);
-    }
-  });
+document.addEventListener("DOMContentLoaded", () => {
+  const cachedData = localStorage.getItem("pokemons");
+  const cacheTimestamp = localStorage.getItem("pokemons_timestamp");
+
+  if (cachedData && cacheTimestamp && (Date.now() - cacheTimestamp) < CACHE_DURATION) {
+    allPokemons = JSON.parse(cachedData);
+    displayPokemons(allPokemons);
+  } else {
+    fetchPokemons();
+  }
+});
+
+function fetchPokemons() {
+  fetch(`./get-pokemon.php`)
+    .then((response) => response.json())
+    .then((data) => {
+      if (Array.isArray(data)) {
+        allPokemons = data;
+        localStorage.setItem("pokemons", JSON.stringify(allPokemons));
+        localStorage.setItem("pokemons_timestamp", Date.now().toString());
+        displayPokemons(allPokemons);
+      } else {
+        console.error("Unexpected response format:", data);
+      }
+    })
+    .catch((error) => {
+      console.error("Error fetching Pokémon data:", error);
+    });
+}
 
 async function fetchPokemonDataBeforeRedirect(id) {
   try {
-    const pokemon = await fetch(`./get-pokemon.php?id=${id}`).then((res) =>
-      res.json()
-    );
+    const response = await fetch(`./get-pokemon.php?id=${id}`);
+    const text = await response.text();
+    console.log(`Response for Pokémon ID ${id}:`, text);
+    const pokemon = JSON.parse(text);
 
     if (pokemon.error) {
       throw new Error(pokemon.error);
@@ -36,27 +56,10 @@ async function fetchPokemonDataBeforeRedirect(id) {
   }
 }
 
-function cacheImages(pokemons) {
-  pokemons.forEach((pokemon) => {
-    const img = new Image();
-    img.src = pokemon.image_url;
-    img.onload = () => {
-      localStorage.setItem(`pokemon_image_${pokemon.id}`, pokemon.image_url);
-    };
-  });
-}
-
-function getCachedImageUrl(pokemonId) {
-  return localStorage.getItem(`pokemon_image_${pokemonId}`);
-}
-
 function displayPokemons(pokemons) {
   listWrapper.innerHTML = "";
 
   pokemons.forEach((pokemon) => {
-    const cachedImageUrl = getCachedImageUrl(pokemon.id);
-    const imageUrl = cachedImageUrl || pokemon.image_url;
-
     const listItem = document.createElement("div");
     listItem.className = "list-item";
     listItem.innerHTML = `
@@ -64,7 +67,7 @@ function displayPokemons(pokemons) {
             <p class="caption-fonts">#${pokemon.id}</p>
         </div>
         <div class="img-wrap">
-            <img src="${imageUrl}" alt="${pokemon.name}" />
+            <img data-src="${pokemon.image_url}" alt="${pokemon.name}" />
         </div>
         <div class="name-wrap">
             <p class="body3-fonts">#${pokemon.name}</p>
@@ -82,6 +85,38 @@ function displayPokemons(pokemons) {
 
     listWrapper.appendChild(listItem);
   });
+
+  lazyLoadImages();
+}
+
+function lazyLoadImages() {
+  const images = document.querySelectorAll('.img-wrap img[data-src]');
+  const config = {
+    root: null,
+    rootMargin: '0px',
+    threshold: 0.1
+  };
+
+  let observer = new IntersectionObserver((entries, self) => {
+    entries.forEach(entry => {
+      if (entry.isIntersecting) {
+        preloadImage(entry.target);
+        self.unobserve(entry.target);
+      }
+    });
+  }, config);
+
+  images.forEach(image => {
+    observer.observe(image);
+  });
+}
+
+function preloadImage(img) {
+  const src = img.getAttribute('data-src');
+  if (!src) {
+    return;
+  }
+  img.src = src;
 }
 
 searchInput.addEventListener("keyup", handleSearch);