Context Object

The OpContext struct is used to pass operation context information. It contains the following fields:

type OpContext struct {
    Col           *mongo.Collection `opt:"-"` // The collection object
    Fields        []*field.Filed    // Metadata of the struct fields bound to the Collection's generic type
    Doc           any                // Document object (e.g., *T or []*T)
    Filter        any                // Query filter
    Updates       any                // Document updates
    Pipeline      any                // Aggregation pipeline
    MongoOptions  any                // MongoDB operation options
    ModelHook     any                // Model hook
    ReflectValue  reflect.Value     // Reflection value of the Doc (used to dynamically modify the document in plugins)
    StartTime     time.Time         // Operation start time
    Result        any                // Result of the MongoDB collection operation
}

Field Descriptions:

• Col: The *mongo.Collection object.
• Fields: A slice of []*field.Filed objects that store metadata of the structure fields bound to the Collection object’s generic type.
• Doc: The document object, representing the structure bound to the Collection object’s generic type (e.g., *T or []*T).
• Filter: The query filter.
• Updates: The updates to be applied to the document.
• Pipeline: The aggregation pipeline.
• MongoOptions: MongoDB operation options.
• ModelHook: The model hook.
• ReflectValue: The reflection value of Doc, used for dynamically modifying the document object inside plugins.
• StartTime: The start time of the operation.
• Result: The result of the MongoDB collection operation.

Different Operation Types and Their Context Fields

Depending on the operation type, the values of OpContext fields may differ. For example:

• When opType is operation.OpTypeBeforeInsert or operation.OpTypeAfterInsert:

  • opCtx.Doc may be non-nil, and its type could be *struct or []*struct.
  • opCtx.ReflectValue will not be nil.

• When opType is operation.OpTypeBeforeUpdate or operation.OpTypeAfterUpdate:

  • opCtx.Filter and opCtx.Updates may be non-nil.

• When opType is operation.OpTypeBeforeDelete or operation.OpTypeAfterDelete:

  • opCtx.Filter may be non-nil.

• When opType is operation.OpTypeBeforeUpsert or operation.OpTypeAfterUpsert:

  • opCtx.Filter and opCtx.Updates may be non-nil.

• When opType is operation.OpTypeBeforeFind or operation.OpTypeAfterFind:

  • opCtx.Filter may be non-nil.
  • If the type is operation.OpTypeAfterFind, opCtx.Doc may be non-nil.
  • opCtx.Result may be non-nil.

• When opType is operation.OpTypeBeforeAny or operation.OpTypeAfterAny:

  • All fields in OpContext can be referenced according to the descriptions above.

• Regardless of the operation type, the Col, Fields, and StartTime fields of OpContext will never be nil.

• Regardless of the operation type, MongoOptions and Result may be non-nil.

• Whether OpContext.MongoOptions and ModelHook are nil depends on whether the user has set them via Creator, Updater, Deleter, Finder, or Aggregator during the MongoDB operation.