ONELAB JSON interface

ONELAB parameters can be imported and exported in JSON format using the Gmsh API.

A ONELAB database is structured as follows (current version number is at 1.3):

"onelab":{
  "creator":"Gmsh",
  "date":"Mon Jan 01 00:00:00 2000",
  "version":"1.3",
  "parameters":[
      { ... },
      { ... }
  ]
}

All the parameters are given in a single array of parameters.

Each parameter is an object with mandatory members "type", "name" and "values":

 { "type":"number", "name":"Path/to/my numeric parameter", "values":[1.234]}
 { "type":"string", "name":"Path/to/my string parameter", "values":["a string"]}

• "type" (string): either "number" or "string"
• "name" (string): the name of the parameter in the ONELAB database, in the form of a /-separated path
• "values" (array) is an array of numbers or strings, depending on the value of "type"

Other optional members common to both "number" and "string" parameters:

• "visible" (boolean): should the parameter be visible in the GUI?
• "readOnly" (boolean): if true, the parameter cannot be changed in the GUI
• "highlight" (string): color used to draw the widget in the GUI
• "closed" (boolean): should the subtree containing this variable be closed?
• "help" (string): help string for the parameter, displayed in a tooltip in the GUI
• "label" (string): alternative label used in the GUI, replacing the part of "name" located after the last /
• "attributes" (object): optional string attributes
  • "AutoCheck" (string): if set to "0", disable the automatic ONELAB "check" event when the value is changed
  • "GmshOption" (string):
  • "Units"" (string): appends the given string after the variable name between square brackets
  • "Persistent" (string): if set to "1", the parameter is not removed when the database is reset
  • "ServerAction" (string): "Reset" (to force a full model reset), "ResetDatabase" (to force a full database reset)
  • "ServerActionReset", "ServerActionHide" or "ServerActionShow" (string): reset, hide or show the parameters with comma-separated names given in the string
  • "ServerActionReset value", "ServerActionHide value" or "ServerActionShow value" (string): reset, hide or show the parameters with comma-separated names given in the string, if the parameter has value value
  • "ServerActionResetMatch", "ServerActionHideMatch" or "ServerActionShowMatch" (string): reset, hide or show the parameters given by the regular expression in the string
  • "ServerActionResetMatch value", "ServerActionHideMatch value" or "ServerActionShowMatch value" (string): reset, hide or show the parameters given by the regular expression in the string, if the parameter has value value
  • "ServerActionSet" (string): set parameters to given values, with the parameter names and the values given as a comma-separated list in the string
  • "ServerActionSet value" (string): set parameters to given values, with the parameter names and the values given as a comma-separated list in the string, if the parameter has value value

Optional members for "number" parameters:

• "min" (number): minimum value allowed when scrolling in the GUI, and when looping on the parameter
• "max" (number): maximum value allowed when scrolling in the interface, and when looping on the parameter
• "step" (number): step value used when scrolling in the interface, and when looping on the parameter
• "choices" (array of numbers): possible choices for the parameter
• "valueLabels" (object): string labels for each the choices, i.e. {"label1":choice1, "label2":choice2, ...}
• "attributes" (object):
  • "ReadOnlyRange" (string): if set to "1", treat the range (or the choices, if they are provided) as read-only
  • "Loop" (string): loop over the parameter, with the string indicating the loop imbrication level (currently "1", "2" or "3")
  • "Graph" (string): display the list of values stored in "choices" as a 2D graph. The string encodes for which coordinate (x or y) in the predefined graphs (top left, top right, ...) the values will be used. Each graph is encoded as 4 characters, corresponding to the use of the values as the x, y, x' and y' coordinates (x' and y' are used when two curves should be drawn on the same graph): possible character values are 0 (value not used), 1 (iso-values), 2 (continuous map), 3 (discrete map), 4 (numeric value). The first group of 4 characters controls the pre-defined top-left graph, the second group controls the top-right graph, etc. For example, the string "0200" will use the values for the y coordinates on the top-left graph, displaying the curve with the continuous style; the string "10000200" will use the data for the x coordinates on the top-left graph and also use them as the y coordinates on the top-right graph
  • "NumberFormat" (string): display the value using the given printf-style formatting string, instead of the default "%g"

Optional members for "string" parameters:

• "kind" (string): mutable kind of the string (currently: "" or "file")
• "choices" (array of strings): possible choices for the parameter
• "attributes" (object): optional string attributes
  • "MultipleSelection" (string): allow multiple selection in choices. The string indicates the initial selection pattern, e.g. "1001111"
  • "Macro" (string): if the string is "Action", trigger a ONELAB "check" event with the ONELAB parameter "ONELAB/Action" set to the value of the parameter; if the string is "GmshMergeFile", trigger Gmsh to merge the file with name given by the value of the parameter; if the string is "GmshParseString", trigger Gmsh to parse the string given by the value of the parameter