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Contracts

A contract is the base model that structure a JSON communication between the BFF and the app.

Currently, we have only one type of contract that is Screen, but we are working to abstract the idea of contract to allow different schemas.

Screen Contract

This contract contains the information to create an entire UI screen and all its life cycle.

It contains four attributes:

  1. metadata: It is an object that contains:
    1. id: Identifier of the screen. It's required.
    2. version: The version of the contract.
    3. flow: The identifier of the flow to which the screen belongs. Optional
  2. actions: This actions will be executed through out the life cycle of the screen:
    1. didLoad: Array of Actions excuted when the data is loaded.
    2. willAppear: Array of Actions excuted each time the screen is shown.
    3. willDisappear: Array of Actions excuted each time the screen is hidden.
    4. back: Array of Actions executed when the user goes back.
  3. keepInStack: Boolean that indicate if the screen should be kept in stack once its dissapeared. Optional.
  4. backgroundColor: String of a color in hexadecimal form. Its the background color of the entire screen.
  5. ui: Array of Widgets that conform the user interface of the screen.
screenSchema.json
{
    "metadata": {
        "id": "string",
        "version": "string",
        "flow": "string"
    },
    "actions": {
        "didLoad": "[Action]",
        "willAppear": "[Action]",
        "willDisappear": "[Action]",
        "back": "[Action]"
    },
    "keepInStack": "boolean",
    "backgroundColor": "string",
    "ui": "[Widget]"
}

Here's an example of a screen:​

https://run.mocky.io/v3/f960b018-feca-4860-bcaf-b31b66bd95b7