Variables

Conditions

You may want to conditionally hide buttons, or visibly disable them, based on the current application state: Whether a job is currently running, whether the pendant is running in a web browser or a Stream Deck, whether gcode has been loaded, and so on.

The disabled and if properties of a button’s configuration are strings which are evaluated with a limited set of javascript.

Math, ternary, numeric comparison and logical operators are allowed, but methods may not be executed.

Most of the application state is available for these conditions, see variables

Conditions which are evaluated to a truthy value will be shown for if properties, or disabled for disabled properties. Conditions which evaluate to a falsy value will be hidden for if properties, or enabled for disabled properties.

example

{
  "buttons": {
    "web_only_alarm_button": {
      "if": "ui.web",
      "disabled": "!cnc.alarm"
    },
    "increase_feed_rate": {
      "disabled": "cnc.overrides.feed === 200"
    }
  }
}

Templates

A button’s text configuration value can be used to display a plain text string, but it can also act as a simple text template, containing and displaying application state information, which will be updated and re-rendered whenever any of the referenced state changes.

A text template is a string containing {{ code }}. Code within these braces will be evaluated with the same rules as conditions.

example

{
  "buttons": {
    "hello_world": {
      "text": "hello world!"
    },
    "Current X Position": {
      "text": "X Position: {{cnc.mpos.x}}"
    }
  }
}

Variables

Variables represent pieces of application state that can be used for conditions and text templates. Some of these values are internal only, and unlikely to be useful for button display. These have not been documented below.

These variables are available under 3 different objects: ui, cnc and gcode.

ui

State related to the current pendant user interface

cnc

State related to the machine or cncjs’s

gcode

State related to the currently loaded gcode.