uni/year2/semester1/logseq-stuff/pages/Firebase Functions.md

• #CT216 - Software Engineering I
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• Firebase Functions is a compute service that lets you run code without provisioning or managing servers.
  • Similar to AWS Lambda, Azure Functions, etc.
    • It runs your code only when needed and scales automatically, from a few requests per day to thousands per second.
    • You pay only for the compute time you consume - there is no charge when your code is not running.

• HTTP Requests

  • HTTP Verbs

    • GET and POST are HTTP request methods to transfer data from client to server.
      • Both can be used to send requests & receive responses.
    • PUT is used to update / replace, DELETE is used to delete, & PATCH is used to partially update / modify.

    • GET

      • GET is designed to request data from a specified resource.
      • GET requests can be cached.
      • GET requests remain in the browser history (you can go back).
      • GET can't be used to send binary data, like images or word documents to the server.
      • GET requests can be bookmarked.
      • GETrequests have length restrictions.
      • GET requests should only be used to retrieve data.
      • Using GET, data can be sent to the server by adding name=value pairs at the end of the URL, i.e., Querystring.

    • POST

      • POST is designed to submit data to the specified resource.
      • POST requests are never cached.
      • POST requests do not remain in the browser history.
      • POST requests cannot be bookmarked.
      • POST requests have no restrictions on data length.
      • The POST method can be used to send ASCII as well as binary data.
      • Form data is often sent to the server via a POST request.

    • GET vs POST

      • Use GET if you are requesting a resource.
        • You may need to send some data to get the correct response back, but in general the idea is to GET a resource.
      • Use POST if you want to send data to the server.

  • Request Structure #card

    card-last-interval:: -1 card-repeats:: 1 card-ease-factor:: 2.5 card-next-schedule:: 2022-11-15T00:00:00.000Z card-last-reviewed:: 2022-11-14T15:50:44.830Z card-last-score:: 1
    • All HTTP requests have three main parts.

    • Request Line

      • HTTP Method (GET, POST, etc.).
      • URL - the address of the resource that is being requested.
      • HTTP version.

    • Headers

      • Additional information passed between the browser & the server, i.e., cookies, browser version, OS version, auth tokens, content-type.

    • Message Body

      • Client & server use the message body to transmit data back & forth between each other.
        • POST requests will usually have data in the body.
        • GET requests leave the message data empty.

  • Postman Client

    • When writing backend APIs, it's often necessary to test it quickly.
      • You don't want to have to write a client-side request to test each API.
      • Sometimes, you may even want to pass in values which would take even longer to code up.
      • Postman can help.
    • Postman is good for testing APIs without having to write client-side code to make the requests.
      • It will work for all request methods, i.e., GET, POST, PUT. etc.
      • You can code the backend, independent of the frontend.

• JSON

  • What is JSON? #card card-last-interval:: 2.8 card-repeats:: 1 card-ease-factor:: 2.6 card-next-schedule:: 2022-11-17T11:23:52.503Z card-last-reviewed:: 2022-11-14T16:23:52.503Z card-last-score:: 5
    • JavaScript Object Notation (JSON) is an open, human & machine readable standard that facilitates data interchange.
    • Along with XML, JSON is the main data interchange format on the web.
    • Firestore uses JSON documents to store records of information.