Configuring

The primary class variables are get and set directly, e.g.:

eva.login = "operator";

API and Authentication

Authentication variables should set before start() method is called - either login/password or API key. If there is auth cookie set, API token variable is filled by the engine automatically.

• login user login

• password user password

• xopts extra login options (EVA ICS v4 only)

• apikey API key

• client_id report a custom client id to the server (e.g. a custom-defined ID of the current UI page)

• api_uri API URI (do not required if working in a web browser)

• set_auth_cookies if true (default), auth cookie is used to store API token.

• api_token current API token, filled automatically after login. Can be filled manually if obtained e.g. for an embedded JS HMI application.

Item processing, special

• debug enable debug mode (1), enable verbose debug mode (2)

• log.records set max. log records to retrieve from the server.

• state_updates Possible values:

  • true (default) - get states of all items API key has access to

  • [ ‘oidmask1’, ‘oidmask2’ ] - (v4) specified subscriptions for EVA ICS v4 (e.g. ‘sensor:env/#’)

  • false - disable state updates

• ws_mode use web sockets. Set automatically if WebSocket object is detected, can be set to “false” manually before engine start.

• clear_unavailable if true, item state is set to null, if the one is no longer available on the back-end (default: false).

• log_params log processing params

Read-only informational variables

• version engine version

• authorized_user current authorized user

• logged_in boolean, set to true when user is logged in

• ws engine web socket object

• log.level current log level (for log processing)

• log_level_names dictionary of log level names (code: name)

• in_evaHI true if the engine runs in evaHI-based web client

• server_info contains actual server info (output of API test method)

• tsdiff time difference between client and server

Loading configuration

The engine has got a built-in method to load configuration JSON:

eva.load_config("path/to/config.json").then((_config) => start_your_hmi());

If the path is not specified, the engine tries to load config.json file from the path where the compiled JS is located.

The config has the following format:

{
  "engine": {
    "api_uri": "API_URI",
    "api_key": "SECRET",
    "debug": false,
    "login": "user",
    "password": "secret",
    "set_auth_cookies": true,
    "state_updates": true,
    "wasm": false,
    "ws_mode": true,
    "log_params": {
      "level": 20,
      "records": 200
    }
    "interval": {
      "ajax_reload": 2,
      "log_reload": 2,
      "action_watch": 0.5,
      "heartbeat": 5,
      "reload": 5,
      "restart": 1,
      "ws_buf_ttl": 0
    }
  }
}

All the configuration fields are optional.