Build a Blog in JavaScript with Headless Oracle Content and Experience

Introduction

Nowadays it’s easy to build complex websites using the latest JavaScript frameworks, like Angular, React, and Vue.js. However, using those frameworks is not mandatory, and we can also build websites with pure JavaScript. In addition, if we combine the power of a content management system (CMS) with pure JavaScript websites, the output is pretty competitive. Fortunately, Oracle Content and Experience (OCE), with its rich headless CMS capabilities, has a graceful solution.

In this tutorial we’ll build a simple blog in JavaScript by leveraging Oracle Content and Experience as a headless CMS, as well as its software development kit (SDK) for content delivery in JavaScript. This JavaScript sample is available on GitHub.

The tutorial consists of three steps:

  1. Prepare Oracle Content and Experience
  2. Build the Blog in JavaScript
  3. Prepare your application for deployment

Prerequisites

Before proceeding with this tutorial, we recommend that you read the following information first:

To follow this tutorial, you’ll need:

What We’re Building

Our blog will consist of a three-page site that lets visitors explore blog articles organized into topics. The first page, the home page, will consist of branding (company name and logo), some links, and a list of blog topics.

To take a look at what we’re building, here’s the end state of our tutorial, a basic JavaScript blog that consumes content from Oracle Content and Experience:

https://headless.mycontentdemo.com/samples/oce-javascript-blog-sample

This is what the home page will look like at the end of this tutorial:

This image shows the home page for Cafe Supremo demo site with a list of the available topics.

The second page, the topic page, shows previews of each blog article that belongs to the topic. Here’s how an individual topic page will look:

This image shows a topic page called ‘Recipes’ with a list of the available articles for that topic.

Lastly, the article page renders the final blog article, including information about the blog’s author. Here’s how an individual article page will look:

This image shows an individual article page, with the content and an author reference.

To proceed, you’ll need to have an active subscription to Oracle Content and Experience and be logged in with the Content Administrator role.

Step 1: Prepare Oracle Content and Experience

If you don’t already have an Oracle Content and Experience instance, see the Quick Start to learn how to register for Oracle Cloud, provision an Oracle Content and Experience instance, and configure Oracle Content and Experience as a headless CMS.

For this tutorial, you’ll need to create a content model in either of two ways. There’s a downloadable asset pack available that will fill your empty repository with content types and associated content, or you can create your own content model and content.

To prepare Oracle Content and Experience:

  1. Create a channel and asset repository.
  2. Create a content model using either of two methods:

Create a Channel and Asset Repository

You first need to create a channel and an asset repository in Oracle Content and Experience so you can publish content.

To create a channel and an asset repository in Oracle Content and Experience:

  1. Log in to the Oracle Content and Experience web interface as an administrator.

  2. Choose Content in the left navigation menu and then choose Publishing Channels from the selection list in the page header.

    This image shows the Publishing Channels option selected in the dropdown menu in the Content page header.

  3. In the upper right corner, click Create to create a new channel. Name the channel ‘OCEGettingStartedChannel’ for the purpose of this tutorial, and keep the access public.

    This image shows the publishing channel definition panel, with ‘OCEGettingStartedChannel’ in the channel name field.

  4. Click Save to create the channel.

  5. Choose Content in the left navigation menu and then choose Repositories from the selection list in the page header.

    This image shows the Repositories option selected in the dropdown menu in the Content page header.

  6. In the upper right corner, click Create to create a new asset repository. Name the asset repository ‘OCEGettingStartedRepository’ for the purpose of this tutorial.

    This image shows the repository definition panel, with ‘OCEGettingStartedRepository’ in the repository name field.

  7. In the Publishing Channels field, select the OCEGettingStartedChannel channel to indicate to Oracle Content and Experience that content in the OCEGettingStartedRepository repository can be published to the OCEGettingStartedChannel channel. Click Save when you’re done.

    This image shows the repository definition panel, with ‘OCEGettingStartedChannel’ in the Publishing Channels field.

Create a Content Model

The next step is to create a content model. You can use either of two methods:

Import the OCE Samples Asset Pack

You can download a preconfigured OCE sample assets pack that contains all required content types and assets for this tutorial. If you prefer, you can also create your own content model rather than download the sample assets pack.

You can upload a copy of the content we’re using in this tutorial from the OCE Samples Asset Pack. This will let you experiment with the content types and modify the content. If you want to import the OCE Samples Asset Pack, you can download the asset pack archive, OCESamplesAssetPack.zip, and extract it to a directory of your choice:

  1. Download the OCE Samples Asset Pack (OCESamplesAssetPack.zip) from the Oracle Content and Experience downloads page. Extract the downloaded zip file to a location on your computer. After extraction, this location will include a file called OCEGettingStarted_data.zip.

  2. Log in to the Oracle Content and Experience web interface as an administrator.

  3. Choose Content in the left navigation menu and then choose Repositories from the selection list in the page header. Now select OCEGettingStartedRepository and click the Import Content button in the top action bar.

    This image shows the Repositories page, with the OCEGettingStartedRepository item selected.

  4. Upload OCEGettingStarted_data.zip from your local computer to the Documents folder.

    This image shows the upload confirmation screen for the OCEGettingStarted_data.zip file.

  5. Once it’s uploaded, select OCEGettingStarted_data.zip and click OK to import the contents into your asset repository.

    This image shows the selected OCEGettingStarted_data.zip file with the OK button enabled.

  6. After the content has been imported successfully, navigate to the Assets page and open the OCEGettingStartedRepository repository. You’ll see that all the related images and content items have now been added to the asset repository.

    This image shows the OCEGettingStartedRepository repository, with all assets that were just imported.

  7. Click Select All on the top left and then Publish to add all the imported assets to the publishing channel that you created earlier, OCEGettingStartedChannel.

    This image shows the OCEGettingStartedRepository repository, with all assets selected and the Publish option in the action bar visible.

  8. Before publishing, you need to validate all the assets. First add OCEGettingStartedChannel as a selected channel, and then click the Validate button.

    This image shows the Validation Results page, with the OCEGettingStartedChannel channel added in the Channels field, all assets to be validated, and the Validate button enabled.

  9. After the assets have been validated, you can publish all the assets to the selected channel by clicking the Publish button in the top right corner.

    This image shows the Validation Results page, with the OCEGettingStartedChannel channel added in the Channels field, all assets validated, and the Publish button enabled.

Once that’s done, you can see on the Assets page that all assets have been published. (You can tell by the icon above the asset name.)

This image shows the Assets page, with all assets pubished.

After importing the OCE Samples Asset Pack, you can start building the blog in Javascript.

Create Your Own Content Model

Instead of importing the OCE Samples Asset Pack, you can also create your own content model.

For this tutorial, we’re using a content type called ‘OCEGettingStartedHomePage’ to build the home page for our blog. This home page consists of branding (company name and logo), some URLs for links, and a list of blog topics that should be included on the page.

This image shows the home page for the Cafe Supremo demo site.

To create content types for the content model:

  1. Log in to the Oracle Content and Experience web interface as an administrator.
  2. Choose Content in the left navigation menu and then choose Asset Types from the selection list in the page header.
  3. Click Create in the top right corner.
  4. Choose to create a content type (not a digital asset type). Repeat this for all required content types.

This image shows the Create Asset Type dialog in the Oracle Content and Experience web interface.

We’ll create four content types, each with its own set of fields:

The first content type, OCEGettingStartedHomePage, should have the following fields:

Display Name Field Type Required Machine Name
Company Name Single-value text field X company_name
Company Logo Single-value text field X company_logo
Topics Multiple-value reference field X topics
Contact URL Single-value text field X contact_url
About URL Single-value text field X about_url

This is what your OCEGettingStartedHomePage content type definition should look like:

This image shows the definition for the content type ‘OCEGettingStartedHomePage’. It includes these data fields: Company Name, Company Logo, Topics, Contact URL, and About URL.

The second content type, OCEGettingStartedTopic, should have the following field:

Display Name Field Type Required Machine Name
Thumbnail Single-value image field X thumbnail

This is what your OCEGettingStartedTopic content type should look like:

This image shows the definition for the content type ‘OCEGettingStartedTopic’. It includes this data field: Thumbnail.

The third content type, OCEGettingStartedAuthor, should have the following fields:

Display Name Field Type Required Machine Name
Avatar Single-value image field X avatar

This is what your OCEGettingStartedAuthor content type should look like:

This image shows the definition for the content type ‘OCEGettingStartedAuthor’. It includes this data field: Avatar.

The fourth and final content type, OCEGettingStartedArticle, should have the following fields:

Display Name Field Type Required Machine Name
Published Date Single-value date field X published_name
Author Single-value reference field X author
Image Single-value image field X image
Image Caption Single-value text field X image_caption
Article Content Single-value large-text field X article_content
Topic Single-value reference field X topic

This is what your OCEGettingStartedArticle content type should look like:

This image shows the definition for the content type ‘OCEGettingStartedArticlePage’. It includes these data fields: Published Date, Author, Image, Image Caption, Article Content, and Topic.

Once you’ve created your content types, you can add these content types to the repository that you created earlier, OCEGettingStartedRepository:

  1. Log in to the Oracle Content and Experience web interface as an administrator.
  2. Navigate to OCEGettingStartedRepository.
  3. Edit the repository and, under Asset Types, specify all four newly created content types.
  4. Click the Save button to save the changes.

This image shows the Edit Repository page in Oracle Content and Experience, with the four newly created content types associated with the OCEGettingStartedRepository repository.

After adding the content types to the repository, you can open the OCEGettingStartedRepository repository on the Assets page and start creating your content items for all the content types.

This image shows content items on the Assets page in the Oracle Content and Experience web interface, with options on the left for collections, channels, languages, types, content item selection, and status.

Step 2: Build the Blog in JavaScript

To consume our Oracle Content and Experience content in JavaScript, we can use the JavaScript blog sample, which is available as an open-source repository on GitHub.

Note: Remember that using the JavaScript sample is optional, and we use it in this tutorial to get you started quickly.

To build the blog in JavaScript:

  1. Clone the sample repository and install dependencies
  2. Configure the JavaScript application
  3. Work with the OCE Content SDK
  4. Use the OCE Content SDK to Fetch Content

Clone the Sample Repository and Install Dependencies

The JavaScript blog sample is available as an open-source repository on GitHub.

You’ll first need to clone the sample from GitHub to your local computer and change your directory into the repository root:

git clone https://github.com/oracle/oce-javascript-blog-sample.git
cd oce-javascript-blog-sample

You can either modify the files in the starter directory or skip the steps after installing dependencies by using the contents of the completed directory.

Now that you have your code base, you need to download dependencies for the application. Run the following command from either the starter or completed directory, whichever you have chosen:

npm install

If you’re in the starter folder, you can proceed with configuring your JavaScript application.

If you’re in the completed folder, to see the completed code base, you can skip to prepare your application for deployment.

Configure the JavaScript Application

In this JavaScript blog sample, you need to configure a few pieces of information so that your Oracle Content and Experience Content SDK (and any other requests) can target the correct instance URL and API version with the correct channel token. These values are used in src/scripts/server-config-utils.js to instantiate a new delivery client.

Open src/config/oce.json in a text editor. You’ll see the following information:

{
 "serverUrl": "https://samples.mycontentdemo.com",
 "apiVersion": "v1.1",
 "channelToken": "47c9fb78774d4485bc7090bf7b955632"
}

Change each key-value pair to reflect your instance URL, the API version you want to target, and the channel token associated with your publishing channel. The channel for this tutorial is OCEGettingStartedChannel.

Work with the OCE Content SDK

Oracle Content and Experience offers a Content SDK in two different versions, depending on whether you’re leveraging it in a client-side context (browser bundle) or in a server-side context (Node.js).

Both SDKs are available as open-source libraries on GitHub:

In addition, the Content SDK is available as an NPM module with each instance of Oracle Content and Experience, where {server} below represents the instance URL (see Quick Start for information about how to retrieve your instance URL):

You may also want to use the minified client-side bundle:

{server}/_sitesclouddelivery/renderer/app/sdk/js/content.min.js

Use the OCE Content SDK to Fetch Content

We can now leverage the Oracle Content and Experience Content SDK to fetch content so that we can render it in our JavaScript application.

To import the OCE Content SDK, specify the following code in the src/config/app-config.js file:

requirejs.config({
  baseUrl: 'lib',
  paths: {
    jquery: 'jquery',
    contentSDK: 'content',
    polyfill: 'polyfill',
    serverUtils: 'server-config-utils',
    services: 'services',
    xss: 'xss',
  },
  shim: {
    xss: {
      exports: 'filterXSS',
    },
  },
});

And use it in the JavaScript files topics_ui.js, article_list_ui.js, and article_ui.js in the src/scripts folder as follows:

define([
  'jquery',
  'contentSDK',
  'serverUtils',
  'services',
], ($, contentSDK, serverUtils, services) => {
}

The OCE Content SDK uses a DeliveryClient object to specify the endpoint. You can make all requests using that client object. Each of the pages creates a delivery client object using createDeliveryClient when the page loads, as follows:

const deliveryClient =
  contentSDK.createDeliveryClient(serverconfig);

The home page loads one content item based on its name, using queryItems. This uses a query that looks for content items of type ‘OCEGettingStartedHomePage’ that have the name ‘HomePage’. Change fetchHomePage() in src/scripts/services.js to use this query:

client.queryItems({
  'q': '(type eq "OCEGettingStartedHomePage" AND name eq "HomePage")',
  'fields': 'all',
})

The topic page shows all articles for a given topic. Again, we use queryItems, this time searching for content items of type ‘OCEGettingStartedArticle’ that reference the topic whose identifier was passed to the page as a query parameter. Change fetchArticles() in src/scripts/services.js to use this query:

client.queryItems({
  'q': ‘(type eq "OCEGettingStartedArticle" AND fields.topic eq
    "${topicId}")‘,
  'fields': 'all',
  'orderBy': 'fields.published_date:desc'
});

The individual article page shows a single article, but the page includes content from Author, which is a separate content type. To fetch one content item plus any content items it references, use getItem() with the expand parameter set to ‘all’. Change fetchArticle() in src/scripts/services.js to use this query:

client.getItem({
  'id': articleId,
  'expand': 'all'
});

Now that we have our data queries, we can render the responses in our JavaScript pages.

JavaScript Files

The next few sections provide an overview of how JavaScript renders our data in each of the JavaScript files.

topics_ui.js File

As we saw previously, the home page consists of a topics list composed of individual topics.

Open the topics_ui.js file, located at src/scripts. Note the invocation of the fetchHomePage() method, which is defined as follows in src/scripts/services.js:

fetchHomePage(client) {
  return client.queryItems({
    'q': '(type eq "OCEGettingStartedHomePage" AND name eq "HomePage")',
    'fields': 'all',
  }).then((topLevelItem) => {
      const returnVal = {
        logoID: topLevelItem.items[0].fields.company_logo.id,
        title: topLevelItem.items[0].fields.company_name,
        topics: topLevelItem.items[0].fields.topics,
        aboutUrl: topLevelItem.items[0].fields.about_url,
        contactUrl: topLevelItem.items[0].fields.contact_url,
      };
      return returnVal;
    });
}

Back in our topics list container component, we retrieve what’s necessary for rendering the home page:

services.fetchHomePage(deliveryClient)
  .then((topLevelItem) => {
    $('#spinner').hide();
    populateHeaderTitle(topLevelItem.title);
    populateHeaderImage(deliveryClient, topLevelItem.logoID);
    populateHeaderUrls(topLevelItem.aboutUrl, topLevelItem.contactUrl);

    const container = $('#topics');
    const topicIdentifiers = topLevelItem.topics.map(
      (topic) => topic.id,
    );
    populateTopicListing(deliveryClient, topicIdentifiers, container);
  })
  .catch((error) => {
    $('#spinner').hide();
    console.log(error); // Error getting top level elements
    displayError();
});

The topic item, on the other hand, represents an individual topic in the list.

Note the invocation of the fetchTopic() method, defined as follows in src/scripts/services.js:

fetchTopic(client, topicId) {
  return client
    .getItem({
      'id': topicId,
      'fields': 'all',
      'expand': 'all',
    })
    .then((topic) => topic);
  }

Back in our topics_ui.js file, we retrieve what’s necessary for rendering each topic item.

services.fetchTopic(deliveryClient, id)
  .then((topic) => {
    // assign a click event on the topic container
    topicContainer.click(() => {
      window.location.href = `./articles.html?topicName=${encodeURIComponent(
        topic.name,
      )}&topicId=${encodeURIComponent(topic.id)}`;
    });
    appendTopicTitle(topicContainer, topic.name);
    appendTopicThumbnail(
      deliveryClient,
      topicContainer,
      topic.fields.thumbnail.id,
    );
    appendTopicDetail(topicContainer, topic.description);
  })
  .catch((error) => console.error(error));

articles_list_ui.js File

As for our list of articles on each individual topic page, we need to retrieve the associated list of articles.

Open the articles_list_ui.js file, located in the src/scripts folder. Note the invocation of the fetchArticles() method, defined as follows in src/scripts/services.js:

fetchArticles(client, topicId) {
  return client
    .queryItems({
      'q': `(type eq "OCEGettingStartedArticle" AND fields.topic eq "${topicId}")`,
      'fields': 'all',
      'orderBy': 'fields.published_date:desc',
    })
    .then((articles) => articles.items);
}

Back in our articles_list_ui.js file, we retrieve what’s necessary for rendering the list of articles.

services.fetchArticles(deliveryClient, topicId)
  .then((articles) => {
    $('#spinner').hide();
    // populate breadcrumb
    $('#breadcrumb').append(
      `<ul><li><a href="index.html">Home</a></li><li>${topicName}</li></ul>`,
    );

    const container = $('#articles');

    articles.forEach((article) => {
      createArticleListItem(
        deliveryClient,
        container,
        article,
        topicName,
        topicId,
      );
    });
  })
  .catch((error) => {
     $('#spinner').hide();
     console.error(error);
});

article_ui.js File and Image Renditions

Finally, we need to render each individual article page.

Open the article_ui.js file, located in the src/scripts folder. Note the invocation of the fetchArticle() method, defined as follows in src/scripts/services.js:

fetchArticle(client, articleId) {
  return client
    .getItem({
      'id': articleId,
      'expand': 'all',
    })
    .then((article) => article);
}

Back in our article_ui.js file, we retrieve what’s necessary for rendering the article.

services.fetchArticle(deliveryClient, articleID)
  .then((article) => {
    $('#spinner').hide();
    populateTitle(article.name, topicName, topicId);
    populateAuthor(
      deliveryClient,
      article.fields.author,
      article.fields.published_date,
    );
    populateImage(
      deliveryClient,
      article.fields.image.id,
      article.fields.image_caption,
    );
    populateContent(article.fields.article_content);
  })
  .catch((error) => {
    $('#spinner').hide();
    console.error(error);
});

In the process, we also invoke getRenditionURL():

// get the article image URL
services.getRenditionURL(deliveryClient, articleImageIdentifier)
  .then((url) => {
    imgElement.attr('src', url);
  })
  .catch((error) => console.error(error));

The getRenditionURL() method is defined as follows in src/scripts/services.js:

getRenditionURL(client, identifier) {
  const url = client.getRenditionURL({
    'id': identifier,
  });
  return Promise.resolve(url);
}

Finally, we invoke getMediumRenditionURL() to get the thumbnail rendition of the author’s image:

// Get the author's avatar image
services.getMediumRenditionURL(deliveryClient, author.fields.avatar.id)
  .then((url) => {
    imgElement.attr('src', url);
  });

The getMediumRenditionURL() method is defined as follows in src/scripts/services.js:

getMediumRenditionURL(client, identifier) {
  return client
    .getItem({
      'id': identifier,
      'fields': 'all',
      'expand': 'all',
    })
    .then((asset) => {
      const object = asset.fields.renditions.filter(
        (item) => item.name === 'Medium',
      )[0];
      const format = object.formats.filter(
        (item) => item.format === 'jpg',
      )[0];
      const self = format.links.filter((item) => item.rel === 'self')[0];
      const url = self.href;
      return url;
    });
}

As you can see, the OCE Content SDK can help reduce the number of requests you need to manage by wrapping queries.

Step 3: Prepare Your Application for Deployment

Now that we’ve built our JavaScript blog site, we need to see it in a local development server so we can debug any issues and preview the application before it goes live.

Spin Up a Local Development Server

You can start a development server locally by running the following command:

npm start

Then, open your browser to http://localhost:8881/oce-javascript-blog-sample/index.html to see your site in action.

If you have linting configured, you can run a linter using the following command:

npm run lint