Request flow in Lesan

We only accept two types of HTTP methods in Lesan:

  • GET
  • POST

GET Requests:

We accept two models of GET requests:

  • Requests sent to serve a static document.
    In order to receive a static document with a GET request, you must first allow its path to Lesan, for this you only need to add the following settings when calling the runServer function:

      coreApp.runServer({ staticPath: ["/pictures", "/videos"] });

    The staticPath key receives an array of strings

    Now all the files in the pictures or videos folder will be accessible by sending a GET request, for example:

    https://www.xyz.com/pictures/avatar.png

  • Requests sent to receive playground static documents or access to the playground itself.
    In order to access the playground, you must set the playground entry in the runServer function equal to true.

      coreApp.runServer({ playground: true });

    The playground key receives a boolean value.

    Now you can access the playground by sending a GET request to an address similar to http://localhost:1367/playground.
    Note that the following addresses will be accessible together with the playground and will send the necessary data to run the playground:

    • /playground/static/index.css
      which sends the necessary styles for the UI in the playground.
    • /playground/static/bundle.js
      which sends a JS bundle of all the codes needed to run the playground.
    • /playground/static/get/schemas
      which sends two JSON data, schemas and acts, which contain all the information we need in the playground to send requests to the server.

POST Requests:

We accept two models of POST requests:

  • Requests sent to receive data from the server (in fact, these requests are the main requests sent to Lesan).
  • Requests sent to upload a document.

Receive data

To receive data from the Lesan server, you must send a POST request to the final address of Lesan. In the body of this request, must be an object in JSON format with the following keys:

  • The service key is used to select one of the microservices set on the application. This key is optional and by default the value of main is placed in it.
  • The model key is used to select one of the Models added to the application.
  • The act key is used to select one of the Acts added to the application.
  • The details key is used to receive data to be sent from the client side along with data to be delivered to users. This key has two internal keys called get and set, we talked a little about it before.
    • set: It contains the information we need in the Act function.
    • get: Contains selected information that the user needs to be returned. This selection is based on zero or one. Therefore, we can pass this object directly to MongoDB projection.

An example of this JSON object is as follows:

{
  "service": "main",
  "model": "country",
  "act": "addCountry",
  "details": {
    "set": {
      "name": "Iran",
      "population": 85000000,
      "abb": "IR"
    },
    "get": {
      "_id": 1,
      "name": 1,
      "population": 1,
      "cities": {
         "name": 1,
         "population": 1,
      }
    }
  }
}

This request finally reaches the function we specified for Act to extract the necessary information from it and return the information requested by the user.
If you remember, we set up each Act as follows:

coreApp.acts.setAct({
  schema: "user",
  actName: "addUser",
  validator: addUserValidator(),
  fn: addUser,
  preValidation: [setUser, checkLevel],
  preAct: [justAdmin],
  validationRunType: "create",
});

Upload documents

For uploading a document you should send a POST request to Lesan endpoint.