RSS feeds have been around since the 90s as a popular way to get updates from a website. Many websites widely use it, and today it's becoming the primary way podcasts distribute content around different streaming platforms. In this article, we'll be taking the RSS feed from Medium and reading it with GraphQL.
You can find the complete code for this article in our Github examples repository, or watch the video walkthrough on our Youtube channel.
What is an RSS feed exactly? RSS stands for Really Simple Syndication and is a format used to deliver frequently updated content, usually news headlines. It's an XML-based format that allows you to subscribe to a website's feed and receive updates whenever there are new posts or podcasts. The RSS feed is a standard way for a website to keep its content in sync with readers' devices. Let's explore the Medium RSS feed a bit closer.
Exploring the Medium RSS feed
The RSS feed is the best way to read Medium. It's simple and fast, and it updates you whenever a new post is published on your favorite Medium publication. Every Medium user has their RSS feed, which looks like this:
`https://medium.com/feed/@username`
It contains information about the owner of the feed, the author in this case, and all the posts this author has posted to Medium. The documentation for Medium RSS can be found here, which also includes information about getting RSS feeds for Medium publications or tags.
If you don't have a Medium account, you can open the following RSS feed in this browser: https://medium.com/feed/@roy-derks. This feed contains all the blog posts I've posted to Medium and looks like this when you open it in your browser:
The response is in XML, and the posts can be found in the item elements between the channel opening and closing tags. In this element, you can find the title, author, category, URL, and post content in HTML. This feed can be read through the browser, RSS feed readers, or an HTTP request. But in this article, we'll be using GraphQL instead!
Connecting to an RSS feed
We'll be using StepZen to make it possible to connect to the Medium RSS feed using GraphQL. With StepZen, you can create a GraphQL API for all your existing data sources, including REST or SOAP APIs. An RSS feed is very similar to a SOAP API, as both return a response in XML.
To create a new GraphQL API with StepZen, you can use the CLI to import a data source or use GraphQL SDL to configure a GraphQL schema. We'll be doing the second, meaning you need to create a new directory on your machine and place two files in there: index.graphql and rss.graphql. The first is a configuration file that links to the rss.graphql, which contains the connection to the RSS feed.
-
index.graphql
schema @sdl(files: ["rss.graphql"]) {
query: Query
}
-
rss.graphql
type Query {
getPosts(username: String!): JSON
@rest(
endpoint: "https://medium.com/feed/$username"
headers: [
{ name: "Content-Type", value: "text/xml" }
]
transforms: [{ pathpattern: "[]", editor: "xml2json" }]
)
}
To create a GraphQL API based on this schema, you must have the StepZen CLI installed. After installing the CLI, you run the command from your terminal or command line:
`stepzen start`
The CLI asks you what you want to call the endpoint of the GraphQL API (in example api/with-rss). Then it deploys the endpoint to a public or private endpoint, depending on your authentication status. If you haven't signed up for a StepZen account, the GraphQL API will always be public. When you have signed up, it will be a private endpoint protected with your StepZen API key.
In the next section, we'll query the Medium RSS feed with GraphQL.
Querying an RSS feed with GraphQL
We've already created the GraphQL schema and deployed it in the previous section. After running stepzen start, the GraphQL API is available at the endpoint that is displayed in your terminal or command line. If you haven't signed up for StepZen, it looks something like this:
`https://public3b47822a17c9dda6.stepzen.net/api/with-rss/__graphql`
When you have signed up for StepZen, two endpoints are available: A localhost endpoint that contains the GraphiQL IDE and a production-ready endpoint that can be accessed by providing your StepZen API key. Learn more about the different endpoints in the documentation.
We'll be using the public endpoint to explore the GraphQL API using GraphiQL, and you can also use the localhost endpoint if you have a StepZen account. In the GraphiQL IDE, you can paste the following query to get the information from the Medium RSS feed:
query {
getPosts(username: "@roy-derks")
}
You can change the username value and add your own Medium username.
From GraphiQL, you can see a similar result like this:
The response is in JSON instead of the XML response the RSS feed returned earlier. In the GraphQL schema, we've configured the @rest custom directive to transform XML into JSON. This configuration is done within transforms: [{ pathpattern: "[]", editor: "xml2json" }], where xml2json is used for the transformation.
To dynamically select the fields the GraphQL API returns, we need to set a custom response type for the getPosts query. In the last section, we'll use a tool called JSON2SDL to generate the response type.
Creating a custom response type
The query getPosts is now returning the response of the RSS feed with the response type JSON. We want to create a custom response type, so we can dynamically select the returned fields. First, we'll limit the fields that are returned as we only need the author information and posts located in the channel element of the RSS feed.
In the @rest configuration, you can add a resultroot field to just return the channel information:
type Query {
getPosts(username: String!): JSON
@rest(
endpoint: "https://medium.com/feed/$username"
headers: [
{ name: "Content-Type", value: "text/xml" }
]
transforms: [{ pathpattern: "[]", editor: "xml2json" }]
resultroot: "rss.channel"
)
}
When you run the query from the previous section again, you can see that the GraphQL API returns only the channel information from the Medium RSS feed. We can use the response of the GraphQL API to create the custom response type for the getPosts query.
Head over to JSON2SDL, and you can copy-paste the complete JSON response on the left side of the page. Press Convert and JSON2SDL generates the GraphQL type for the response.
You can copy the generated GraphQL types into the top of your rss.graphql file.
type Image {
link: String
title: String
url: String
}
type OneItem {
category: [String]
creator: String
encoded: String
guid: JSON
link: String
pubDate: String
title: String
updated: DateTime
}
type GetPosts {
description: String
generator: String
image: Image
item: [OneItem]
lastBuildDate: String
link: JSON
title: String
webMaster: String
}
And link the type GetPosts to the query to retrieve the posts as its response type.
type Query {
getPosts(username: String!): GetPosts
}
This tells the StepZen GraphQL engine what fields are available to query from the RSS feed. Instead of getting all the data from the Medium RSS feed at once, you can now dynamically select which fields to return. For example, if you only want to get the title and category for the posts, the following query does just that:
query {
getPosts(username: "@roy-derks") {
item {
title
creator
}
}
}
From the GraphQL schema or the GraphiQL IDE, you can see what other fields can be returned. With these steps, you've created a GraphQL API that connects to a Medium RSS feed.
Conclusion
This article taught you how to convert the Medium RSS feed to a GraphQL API. Of course, you can alter it to work with any other RSS feed. You can find the complete code in our Github examples repository, or watch the video on our Youtube channel. We would love to hear what RSS Feed (or SOAP API) you tried converting. Join our Discord to stay updated with our community.
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