https://github.com/stepzen-dev/subscription-blog
https://github.com/stepzen-dev/subscription-blog
Last synced: 11 months ago
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- Host: GitHub
- URL: https://github.com/stepzen-dev/subscription-blog
- Owner: stepzen-dev
- Created: 2022-11-18T01:00:56.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2022-12-13T00:55:37.000Z (over 3 years ago)
- Last Synced: 2025-06-07T15:46:30.285Z (12 months ago)
- Language: JavaScript
- Size: 24.4 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# subscription-blog
A simple example of subscriptions in StepZen. Any query in StepZen can be converted into a subscription. To give an example:
```graphql
type Query {
foo: Foo
@rest (endpoint: "...")
}
type Subscription {
fooSub: Foo @materializer (query:"foo")
}
```
That's it! `foo` can be a `@rest` query, it could be `@dbquery`, it could be a federated `@graphql` query, it could be an `@sequence`. Any way you construct your queries, each and everyone of them can be converted into a subscription! (Underneath the covers, StepZen does long polling to determine what has changed, and more mechanisms are coming, but you can start using it right now, and we will continue to optimize it.)
## Steps for local service
1. Download this repo and `cd subscription-blog/graphql`.
2. If you do not have `stepzen` installed, then `npm install -g stepzen`.
3. `cd graphql && stepzen service start && stepzen login --config ~/.stepzen/stepzen-config.local.yaml`--this starts a local docker container running all of StepZen's services.
4. `stepzen deploy` deploys the `graphql` schema in `index.graphql` to StepZen (on your local machine) and the endpoint is `http://localhost:9000/api/subscription/__graphql`. However, the URL for web sockets is `ws://localhost:9000/stepzen-subscriptions/api/subscription/__graphql`.
5. Now we will have a client that makes subscription requests over WebSockets using graphql-ws to this endpoint. For this, `cd ../client && npm install`.
6. Setup .env; `echo 'APIKEY='$(stepzen whoami --apikey) > .env` (`stepzen whoami --apikey` retrieves your admin key, it shoud look something like: `graphql::local.net...`)
7. `node client.js` and see the magic. You will see the price of `ETHBTC` change and reflected back on your console.
### Steps for the StepZen cloud service
1. Download this repo and `cd subscription-blog/graphql`.
2. Make sure you've registered for an account and setup your cli. [Getting Started](https://stepzen.com/getting-started) has instructions on how to do this.
3. `cd graphql && stepzen deploy` deploys the `graphql` schema in `index.graphql` to the StepZen managed service and the websockets endpoint is `wss://ACCOUNT.stepzen.net/stepzen-subscriptions/api/subscription/__graphql`. Note: the client code below will use the correct wss endpoint if you set STEPZEN_ACCOUNT per step 6.
5. Now we will have a client that makes subscription requests over WebSockets using graphql-ws to this endpoint. For this, `cd ../client && npm install`.
6. Do a `stepzen whoami --apikey` to get your admin key. Edit `.env` and set:
- the value of `APIKEY=` to be this key
- the value of `STEPZEN_ACCOUNT=` to be your stepzen account name
7. `node client.js` and see the magic. You will see the price of `ETHBTC` change and reflected back on your console.
## How this all works
The subscription is against a REST backend: `https://api.binance.us/api/v3/ticker?symbol=ETHBTC` and StepZen does a long polling and pushes back to the client whenever a new value is found.
Because any `Query` field can be exposed as a `Subscription`, you can set up subscription against databases, graphql endpoints, or any combination thereof. Try them for yourself.