TabManager

What is tab_manager about?

Well, it's easy, this is a tab manager. Imagine, you have a bigger group at an event, like a camp. From year to year, the attendance of these events increased, and the administration cost of the open buffet increased at least twice the volume.

Outside of the paperwork, the paper is another problem. Mostly because it is not redundant, and highly...

... well, vulnerable :-)

The Concept

One of the solutions is to put these notes to the cloud, backed by user devices, so the data is kind of distributed, and easily manageable. So the idea was to use smartphones because everybody has at least one in their pocket.

Technical details

The project is strongly in the development phase. We use Flutter and at the moment AWS Ampify. There is an intention to go in a cloud-agnostic manner, but that's not the priority yet.

Basically, you can use this repository to create your own backend, so you can scan the connection data with the official app, or you can simply just compile your own client too.

Build your own backend

Due to Amplify's stupid behaviour, the following steps are required to install your own backend:

• Go to the Amplify in the AWS Console
  • Create new app, name it, launch Studio
• Go to your Terminal and pull the new empty backend:
  • run amplify pull --appID <appid by the studio> --envName <env name by the studio>
  • it will ask a few things, default is usually good
  • important is that you want to modify the backend, so press Y there
• Add the authentication plugin:
  • run amplify add auth
  • default config is okay
  • Email is okay
  • no advanced settings
• Add API plugin:
  • run amplify add api
  • choose GraphQL
  • authorization should be set to Cognito
  • it will ask for additional types, press No
  • conflict detection should be enabled and set to Auto Merge
  • press Continue
  • it will ask about schema, choose Blank Schema
  • it will ask that you wanna edit the schema, do so
  • copy the contents of the Schema section and save it
• Create the backend:
  • runamplify push
  • it will ask for a description, write default
  • it will ask for API key expire, set it to 365

Of course you can select different options, but this is the tested way.

Schema

type Stock @model
  @auth(rules: [{allow: private, operations: [read]}, {allow: groups, groups: ["Admin"]}]) {
  id: ID! @primaryKey
  amount: Int!
  supply_price: Int
  supply_time: AWSDateTime
  product: Product! @belongsTo
}

type Product @model
  @auth(rules: [{allow: private, operations: [read]}, {allow: groups, groups: ["Admin"]}]) {
  id: ID! @primaryKey
  name: String!
  unit_price: Int!
  event: Event! @belongsTo
  stocks: [Stock] @hasMany
  consumptions: [Consumption] @hasMany
}

type Event @model
  @auth(rules: [{allow: private, operations: [read]}, {allow: groups, groups: ["Admin"]}]) {
  id: ID! @primaryKey
  name: String!
  start_date: AWSDate!
  end_date: AWSDate!
  products: [Product] @hasMany
}

type Consumption @model
  @auth(rules: [{allow: private, operations: [read]}, {allow: groups, groups: ["Admin"]}, {allow: owner}]) {
  id: ID! @primaryKey
  product: Product! @belongsTo
  amount: Int!
  time: AWSDateTime!
#  owner: String!
}

Create backend connectors

After [backend setup](#Build your own backend) go to the terminal, and check if your lib/amplifyconfiguration.dart is up to date with your backend's credentials. If not, then run: amplify pull, and now you can run:

flutter pub get
flutter pub run lib/commands/create_qr_backend.dart

It will create a QR code and a connection string. Test both if they are working ;)

Build your own client

Currently not so much, but do not forget to generate the icons, if you have modifications :)

flutter pub get
flutter pub run flutter_launcher_icons:main
flutter build

If you overwrite the lib/amplifyconfiguration.dart with your own generated one, the backend QR screen will be skipped.

Known bugs

With the local data / backend config deletion and logout process the states are mixed up.