ONELAB syntax for Gmsh and GetDP

ONELAB parameters can be defined directly in the input files (.geo and .pro files) through the DefineConstant syntax: <syntaxhighlight lang="cpp"> DefineConstant[ x = {1, Name "My variable"} ]; DefineConstant[ x = {1, Name "My variable", Choices {0,1}} ]; DefineConstant[ x = {1, Name "My variable", Choices {0,3,5}} ]; DefineConstant[ x = {1, Name "My variable", Choices {0="Zero",3="Three", 5="Five"}} ]; DefineConstant[ x = {1, Name "My variable", Min 0, Max 50, Step 5} ] DefineConstant[ x = {1, Name "Variables/Input/My variable", Min 0, Max 50, Step 5} ]; </syntaxhighlight>

When the input file is analyzed, if the parameter has not been previously defined, it takes the value provided in DefineConstant and is sent to the ONELAB server. The "/" character in a variable name is interpreted as a path separator, and results in the creation of a sub-tree in the graphical user interface. If the input file is re-analyzed later, the value will be updated using the value from the server (unless it is labeled ReadOnly: see below). The same syntax can be used to define string parameters: <syntaxhighlight lang="cpp"> DefineConstant[ s = {"a", Name "My string variable"} ]; DefineConstant[ s = {"a", Name "My string variable", Choices {"a", "b", "c"} } ]; DefineConstant[ x = {"a", Name "My string variable", Kind "File"} ] DefineConstant[ x = {"a", Name "Variables/Input/My variable"} ]; </syntaxhighlight>

Note that when the code is run without the ONELAB server, the parameters simply take the default values provided by DefineConstant. An input file modified to create an appealing graphical user interface using ONELAB can thus also be run as-is without ONELAB.

Common parameter attributes

Here's the list of attributes available for all ONELAB parameters:

Name string

The name of the parameter in the ONELAB database, in the form of a "/"-separated path. The Name attribute is mandatory to exchange the variable with the ONELAB server. If no name (and no other attribute) is given, the DefineConstant construct can be used to assign default values to local variables (which will not be sent to the ONELAB server).

ReadOnly 0|1

If ReadOnly is set, the value cannot be changed server-side, and the value provided in DefineConstant is always used

Highlight string

Color used to draw the widget in the graphical interface

Visible 0|1

Should the parameter be visible in the interface?

Closed 0|1

Should the subtree containing this variable be closed?

Help string

Help string for this parameter

AutoCheck 0|1

Allows to disable automatic "check" (rebuild of the interface) when the value is changed

GmshOption string

Treat the parameter as the name of a Gmsh option (e.g. Mesh.Algorithm)

Label string

Alternative label used in the graphical user interface, replacing the part of "Name" located after the last "/"

Number attributes

In addition, numbers can take the following specific attributes:

Min number

Minimum value allowed when scrolling in the interface, 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

Range {min, max, step}

Alternate syntax for Min, Max and Step

Choices{number, number, ...}

Possible choices for the parameter

Choices{number=string, number=string, ...}

Possible choices for the parameter, with string labels for each choice

ReadOnlyRange 0|1

Treat the range (or the choices, if they are provided) as read-only

Loop string

Loop over the parameter (the string indicates the loop imbrication level: currently "1", "2" or "3")

Graph string

String attributes

String accepts the following specific attributes:

Kind string

Mutable kind of the string (currently: "file")

Choices {string, string, ...}

Possible choices for the parameter

MultipleSelection "1001111"

Allow multiple selection in choices. The following string indicates the initial selection pattern.

Macro string

Treat the parameter as the filename of a macro that will be run when the parameter is clicked in the interface