SEAL Operator JSON Schema¶

For each connector type, JSON schema files are available specifying the data structures in the panel and in the server settings. The user interface uses the schema for displaying the user interface elements and for validating the user input before sending data to the server.

Example - panel configuration file, panel.json

{
  "name": "PLOSSYS 4",
  "type": "print",
  "pid": "f75bf1b0-6920-41cb-9fc8-a88191710f41",
  "json_schema": {
    "$schema": "http://json-schema.org/schema#",
    "type": "object",
    "required": ["Printer", "Copies"],
    "properties": {
      "Copies": {
        "type": "number",
        "description": {"de": Exemplare, "en": "Copies"},
        "minimum": 1,
        "default": 1
      }
    },
    "fieldsets": [
      {
        "fields": [
          "Printer",
          "Copies"
        ]
      }
    ]
  }
}

Literature - JSON format and keywords

For further information about the general JSON format, refer to: http://json.org/json-de.html

For a helpful list of the available JSON keywords, refer to: https://ajv.js.org/keywords.html

Top Level Structure¶

name¶

name specifies the panel name displayed in SEAL Operator.

type¶

type specifies the type of the panel.

The value is always print and must not be modified.

pid¶

pid specifies the unique panel ID.

The value must not be modified.

json_schema¶

json_schema specifies the schema definition for the settings area of the panel. For available keys and values, refer to json_schema Structure below.

json_schema Structure¶

json_schema/$schema¶

$schema specifies the used JSON schema.

The value is always http://json-schema.org/schema# and must not be modified.

json_schema/fieldsets¶

The fieldsets array contains the fields displayed in the panel in the user interface. Each field specified in json_schema/properties has to be contained here.

json_schema/properties¶

properties specifies all data elements. Each data element contains an arbitrary name like Copies or PLS_FLAGPAGE used as key for storing the value specified by the user on server side and a set of key value pairs describing the data element.

properties/Capabilities contains special settings which manages the visibility of the user interface elements depending on the information about the printer currently selected, for example, if the printer supports color or which formats are available for the printer.

json_schema/required¶

required specifies the array containing the names of the data elements that have to be specified by the system or user.

json_schema/type¶

type specifies the type of the top level JSON schema element.

The value is always object and must not be modified.

Data Element Structure¶

For each data element, the following keys are available. Here, only the keys relevant for the panel configuration are mentioned:

data_element/description¶

description specifies the label of the field in the user interface. Thereby, different labels for the available languages can be specified.

data_element/maximum¶

maximum specifies the maximum that can be specified by the user if a number ("widget": "number") is specified as user element.

data_element/minimum¶

minimum specifies the minumum that can be specified by the user if a number ("widget": "number") is specified as user element.

data_element/multipleOf¶

multipleOf specifies the steps for the value that can be specified by the user if a number ("widget": "number") is specified as user element.

Example - step for numbers

"Rotation": {
  "type": "number",
  "description": "Rotation",
  "default": 0,
  "minimum": 0,
  "maximum": 270,
  "multipleOf": 90
}

data_element/oneOf¶

oneOf specifies the options among which the user can select if an option menu ("widget": "select") or radio button ("widget": "toggle") is specified as user element.

Example - duplex options

"oneOf": [
  {
  "enum": [
    "NONE"
    ],
  "description": "Simplex"
  },
  {
  "enum": [
    "LONG_SIDE"
    ],
  "description": "Duplex long side"
  },
  {
  "enum": [
    "SHORT_SIDE"
  ],
  "description": "Duplex short side"
  }
]

data_element/readOnly¶

readOnly specifies if the value is read-only. This is particularly interesting for parameters coming from repositories and are just passed through.

Example - read-only

"DocNo": {
  "type": "string",
  "description": "Document Number",
  "readOnly": true
}

data_element/type¶

type specifies the data type of the data element:

boolean allows true and false.
number allows real numbers.
string allows a UTF-8-encoded character sequence.
object is a complex object type composed of properties which could contain objects again. For example, this data type is used for properties/Capabilities.

data_element/visibleIf¶

visibleIf specifies the keys and values on which the current data element depends.

Example - dependency

"MySpecialDuplex": {
  "type": "string",
  "description": "Special duplex value",
  "visibleIf": {
    "Capabilities/Duplex": [
      true
    ]
  }
}

data_element/widget¶

widget specifies the user interface element used for the key.

checkbox is a checkbox.
crop is a an element combining four number fields with percent or fix units.
hidden is an element not displayed in the user interface.
number is an editable field for numbers with a spinbox.
password is an editable field not showing the input, for example, for a password or a PIN.
select is an option menu.
string is a editable text field.
toggle is a radio button.

The available user interface elements depend on the data type:

Data Type	Available Widgets	Default
`object`	`crop`, `hidden`	`hidden`
`string`	`password`, `select`, `string`, `toggle`	`string`
`boolean`	`checkbox`	`checkbox`
`number`	`number`, `password`	`number`

Property to Parameter Mapping¶

Some generally used properties are mapped to settings for the backend system by the correspondent connector. In case of PLOSSYS 4, the following properties are mapped:

SEAL Operator Property	PLOSSYS 4 Header Parameter
Printer	PLS_PLOTTER
Copies	PLS_PLOTCOPY -1
Duplex	PLS_DUPLEX
Quality	PLS_PRINT_QUALITY
Color	PLS_PLOTPEN
Format	PLS_PLOTSCALE
rotationAngle	PLS_PLOT_ROTATE
name	PLS_ORIG_NAME

Hint - Y and N

The PLOSSYS 4 (P4) connector maps any boolean value, for example, true, 1 or NO, to Y or N accordingly and passes this to PLOSSYS 4.