Overridable parameters — MacroParams

A macro can expose values that the user (or a caller of Execute) overrides without editing the code. The macro reads them through the static MacroParams helper; if no override was supplied, the recorded default is used.

In the macro body

Call Initialize once at the start of Run, then read values per step:

MacroParams.Initialize(context.Params);     // context.Params is the overrides JSON

double v = MacroParams.GetFlt(stepIndex, "value", 10.0);   // default 10.0 if not overridden
string  s = MacroParams.GetStr(stepIndex, "fullName", "");
int     i = MacroParams.GetInt(stepIndex, "mode", 0);
bool    b = MacroParams.GetBol(stepIndex, "enabled", false);

• stepIndex is the 0-based index of the step within the macro (the same index used by NotifyMacroStep and by the macro's commands.json).
• The last argument is the default — returned when the user did not override that key. So a macro always runs correctly even with empty params.

The overrides format

context.Params is a JSON dictionary { "stepIndex": { "key": "value" }, ... } — exactly what ICamApiMacroManager.Execute(id, paramsJson) accepts (see ../api/application.md). Empty string = no overrides (all GetXxx return their defaults).

{ "0": { "value": "7.5" }, "3": { "fullName": "Part\\Face1" } }

Values are always strings in the JSON; GetInt/GetFlt/GetBol parse them (invariant culture for floats).

Making a parameter editable in the UI

The macro's commands.json (written next to the built macro) drives the editing UI. Each step's entry may carry editable_params:

{
  "display_text": "Set parameter: SafeZ = {0}",
  "editable_params": [
    { "key": "value", "label": "Safe Z", "type": "flt", "default_value": "5" }
  ]
}

• type is str / bol / int / flt.
• default_value: null (or absent) marks the parameter required — the UI refuses to run until the user supplies a value.
• display_text uses {N} placeholders that the UI replaces with editable fields.

A host can discover these programmatically via ICamApiMacroInfo.Step[i].Param[j] (Key / LabelText / ParamType / Required / DefaultValue / ValuesString) — see ../api/application.md.