1package ole 2 3import "unsafe" 4 5type IDispatch struct { 6 IUnknown 7} 8 9type IDispatchVtbl struct { 10 IUnknownVtbl 11 GetTypeInfoCount uintptr 12 GetTypeInfo uintptr 13 GetIDsOfNames uintptr 14 Invoke uintptr 15} 16 17func (v *IDispatch) VTable() *IDispatchVtbl { 18 return (*IDispatchVtbl)(unsafe.Pointer(v.RawVTable)) 19} 20 21func (v *IDispatch) GetIDsOfName(names []string) (dispid []int32, err error) { 22 dispid, err = getIDsOfName(v, names) 23 return 24} 25 26func (v *IDispatch) Invoke(dispid int32, dispatch int16, params ...interface{}) (result *VARIANT, err error) { 27 result, err = invoke(v, dispid, dispatch, params...) 28 return 29} 30 31func (v *IDispatch) GetTypeInfoCount() (c uint32, err error) { 32 c, err = getTypeInfoCount(v) 33 return 34} 35 36func (v *IDispatch) GetTypeInfo() (tinfo *ITypeInfo, err error) { 37 tinfo, err = getTypeInfo(v) 38 return 39} 40 41// GetSingleIDOfName is a helper that returns single display ID for IDispatch name. 42// 43// This replaces the common pattern of attempting to get a single name from the list of available 44// IDs. It gives the first ID, if it is available. 45func (v *IDispatch) GetSingleIDOfName(name string) (displayID int32, err error) { 46 var displayIDs []int32 47 displayIDs, err = v.GetIDsOfName([]string{name}) 48 if err != nil { 49 return 50 } 51 displayID = displayIDs[0] 52 return 53} 54 55// InvokeWithOptionalArgs accepts arguments as an array, works like Invoke. 56// 57// Accepts name and will attempt to retrieve Display ID to pass to Invoke. 58// 59// Passing params as an array is a workaround that could be fixed in later versions of Go that 60// prevent passing empty params. During testing it was discovered that this is an acceptable way of 61// getting around not being able to pass params normally. 62func (v *IDispatch) InvokeWithOptionalArgs(name string, dispatch int16, params []interface{}) (result *VARIANT, err error) { 63 displayID, err := v.GetSingleIDOfName(name) 64 if err != nil { 65 return 66 } 67 68 if len(params) < 1 { 69 result, err = v.Invoke(displayID, dispatch) 70 } else { 71 result, err = v.Invoke(displayID, dispatch, params...) 72 } 73 74 return 75} 76 77// CallMethod invokes named function with arguments on object. 78func (v *IDispatch) CallMethod(name string, params ...interface{}) (*VARIANT, error) { 79 return v.InvokeWithOptionalArgs(name, DISPATCH_METHOD, params) 80} 81 82// GetProperty retrieves the property with the name with the ability to pass arguments. 83// 84// Most of the time you will not need to pass arguments as most objects do not allow for this 85// feature. Or at least, should not allow for this feature. Some servers don't follow best practices 86// and this is provided for those edge cases. 87func (v *IDispatch) GetProperty(name string, params ...interface{}) (*VARIANT, error) { 88 return v.InvokeWithOptionalArgs(name, DISPATCH_PROPERTYGET, params) 89} 90 91// PutProperty attempts to mutate a property in the object. 92func (v *IDispatch) PutProperty(name string, params ...interface{}) (*VARIANT, error) { 93 return v.InvokeWithOptionalArgs(name, DISPATCH_PROPERTYPUT, params) 94} 95