Custom components define visual forms through Config struct tags. The visual editor (RuleGo-Editor) automatically renders the component configuration UI based on these tags.

Optional Interfaces

Besides the core Node interface, components can implement the following optional interfaces to provide additional information:

ComponentDefGetter — Custom Form Definition

Overrides the auto-generated component form configuration. Non-empty fields in the return value override the auto-generated values:

type ComponentDefGetter interface {
    Def() ComponentForm
}

Example — custom description and relation types:

func (x *MyNode) Def() types.ComponentForm {
    relationTypes := &[]string{types.Success, types.Failure, types.True, types.False}
    return types.ComponentForm{
        Label:         "My Component",
        Desc:          "This is a custom component",
        RelationTypes: relationTypes,
    }
}

CategoryGetter — Custom Category

type CategoryGetter interface {
    Category() string
}

DescGetter — Custom Description

type DescGetter interface {
    Desc() string
}

Config Struct Tags

Custom component Config structs support the following tags for visual editor form rendering:

Tag	Description	Example
json	Field name	json:"delayMs"
label	Display name	label:"Delay (ms)"
desc	Field description	desc:"Delay time in milliseconds"
required	Whether required	required:"true"
component	UI component type	component:"{\"type\":\"select\",\"options\":[...]}"
ref	Shared node association	ref:"primary"

component tag examples

Dropdown select:

RequestMethod string `json:"requestMethod" label:"Request Method"
    component:"{\"type\":\"select\",\"options\":[{\"label\":\"GET\",\"value\":\"GET\"},{\"label\":\"POST\",\"value\":\"POST\"}]}"`

Code editor:

JsScript string `json:"jsScript" label:"Script"
    component:"{\"type\":\"codeEditor\",\"language\":\"javascript\"}"`

Shared Node Pool (SharedNode)

For components that need shared connections or resources (such as MQTT clients, database connection pools), you can use the shared node pool pattern. Multiple rule nodes reuse the same underlying connection instance, avoiding repeated creation.

Use the ref tag in the Config struct to identify the relationship between fields and the shared node:

type MqttClientNodeConfiguration struct {
    Server   string `json:"server" label:"Server Address" required:"true" ref:"primary"` // Reference field
    Username string `json:"username" label:"Username" ref:"shared"`                      // Provided by shared node
    Password string `json:"password" label:"Password" ref:"shared"`                      // Provided by shared node
    Topic    string `json:"topic" label:"Topic" required:"true"`                         // Component's own field
}

• ref:"primary" — The identifier field for the ref:// reference address
• ref:"shared" — Configuration field provided by the shared node, hidden when using references
• No ref — Component's own business field, always displayed

Related Documentation

• Component Form Conventions — Complete form generation rules and endpoint component conventions
• Get Component Configuration Form — ComponentForm and ComponentFormField complete field reference
• Custom Components Overview — Component interfaces and development guide