WordPress-Fetch-Posts/blog.js

/**
 * The base URI for the WordPress API. Don't forget `http(s)://`!
 * Depending on where your WordPress blog is hosted, this could be something like: `https://example.wordpress.com`
 */
const wordPressBaseUri = 'https://wptest.decicus.com';

/**
 * The selector for the container where we want to put the posts.
 * By default it is `#blog-posts` (element with ID "blog-posts"), which you can find in `blog.html`
 */
const postsContainerSelector = '#blog-posts';

/**
 * The selector for the "View More" button.
 * By default it is `#view-more` (element with ID "view-more"), which you can find in `blog.html`
 */
const viewMoreButtonSelector = '#view-more';

/**
 * Classes to add to the post's parent div.
 * By default these are Tailwind CSS classes: https://tailwindcss.com/
 */
const postElementClasses = ['bg-rose-900', 'p-4', 'my-4'];

/**
 * Classes to add to the post's title.
 * By default these are Tailwind CSS classes: https://tailwindcss.com/
 */
const postTitleClasses = ['text-xl', 'font-bold', 'mb-2'];

/**
 * Class to add to the "View More" button when there are no more posts to fetch.
 * By default this is a Tailwind CSS class called `hidden`: https://tailwindcss.com/docs/display#hidden
 */
const hideClass = 'hidden';

/**
 * Fetches 10 posts from WordPress API.
 * Uses: https://developer.wordpress.org/rest-api/reference/posts/#list-posts
 * 
 * @param {Number} page Which page to fetch, by default the first page (1)
 * @param {Number} perPage How many posts to fetch per page, by default 10
 * @returns {Array}
 */
async function fetchPosts(page = 1, perPage = 10)
{
    const response = await fetch(`${wordPressBaseUri}/wp-json/wp/v2/posts?page=${page}&per_page=${perPage}`);
    const json = await response.json();
    return json;
}

/**
 * Used for tracking what "page" from the WordPress API we should be fetching.
 * You should generally not change this value.
 */
let nextPage = 1;

/**
 * Can be used for tweaking how many posts to get per page.
 * Will also affect how many times you have to click "View more" to get all posts
 */
const perPage = 10;

const viewMoreButton = document.querySelector(viewMoreButtonSelector);
async function getPosts()
{
    // Disable the "View More" button while we're fetching posts, to avoid people spamming the button
    viewMoreButton.setAttribute('disabled', '1');

    // Get the first set of posts from the API
    const posts = await fetchPosts(nextPage, perPage);

    // Get the container where we want to put the posts. By default this can just be an empty div.
    const postsContainer = document.querySelector(postsContainerSelector);

    /**
     * Style points only
     */
    let firstPostId = null;

    // Loop though the posts and create the HTML elements for each post
    for (const post of posts)
    {
        /**
         * Style points only
         * 
         * Since `firstPostId` is still `null`, we set it to the post's ID.
         * Any further posts in this batch will *not* override it.
         * Meaning it will in fact be "the first post" (of this batch).
         */
        if (firstPostId === null)
        {
            firstPostId = post.id;
        }

        // Create post's parent div
        const postElement = document.createElement('div');
        postElement.setAttribute('data-post-id', post.id);
        postElement.classList.add('post');

        /**
         * Adding classes to the post's parent div.
         * Primarily for styling purposes.
         */
        for (const postElementClass of postElementClasses)
        {
            postElement.classList.add(postElementClass);
        }

        // Create post's title as a h2
        const postTitle = document.createElement('h2');
        postTitle.textContent = post.title.rendered;

        /**
         * Adding classes to the post's title.
         * Primarily for styling purposes.
         */
        for (const postTitleClass of postTitleClasses)
        {
            postTitle.classList.add(postTitleClass);
        }

        // Create post's content. This is a div because WordPress will give you a lot of HTML tags in the content (e.g. `p`).
        const postContent = document.createElement('div');
        postContent.innerHTML = post.content.rendered;

        // Append the title and content to the post's parent div
        postElement.appendChild(postTitle);
        postElement.appendChild(postContent);

        // Append the post's parent div to the container
        postsContainer.appendChild(postElement);
    }

    /**
     * Style points only
     * Only trigger this logic after the "view more" button has been pressed
     */
    if (nextPage > 1) {
        /**
         * Style points only
         * Scroll to the first post we got from the API.
         * This will scroll to the first post of the current batch of posts
         */
        const firstPost = document.querySelector(`[data-post-id="${firstPostId}"]`);
        firstPost.scrollIntoView({ behavior: 'smooth' });
    }

    /**
     * If the amount of posts we got from the API is less than the amount of posts we requested,
     * then we know that we have reached the end of the posts and we can hide the "View More" button.
     */
    const viewMoreClasses = viewMoreButton.classList;
    if (posts.length >= perPage)
    {
        viewMoreClasses.remove(hideClass);

        // Increase `nextPage` by 1 so that the next time we fetch posts, we get the next page
        nextPage++;
    }
    /**
     * If the amount of posts we got from the API is less than the amount of posts we requested,
     * then we know that we have reached the end of the posts and we can hide the "View More" button.
     */
    else {
        viewMoreClasses.add(hideClass);
    }

    // Re-enable the "View More" button
    viewMoreButton.removeAttribute('disabled');
}

// Add an event listener to the "View More" button so that we can fetch more posts when it's clicked
viewMoreButton.addEventListener('click', getPosts);

// Run the `getPosts` function once when the page loads
getPosts();