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duck.pas
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duck.pas
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unit duck;
// *****************************************************************************
// DUCK DUCK DELPHI
// *****************************************************************************
//
// Original Author:
// Jason Southwell
//
// Description:
// This unit adds simple duck typing to Delphi objects with RTTI and
// provides an RTTI helper class to simplify many common RTTI tasks.
//
// For more information on Duck Typing, please check out this article on
// wikipedia:
// http://en.wikipedia.org/wiki/Duck_typing
//
// For more information on this project, please visit:
// http:/arcana.sivv.com/duckduckdelphi
//
// *****************************************************************************
// DUCK TYPING
// *****************************************************************************
//
// Instead of:
// if obj is TControl then
// TCoontrol(obj).Visible := True
//
// You can simply call
// obj.duck.setTo('Visible',True);
//
// If the property does not exist on the object, the call fails silently.
//
// If you must know that the property can be set:
// if obj.duck.has('Visible') then
// obj.duck.setTo('Visible',True);
//
// "obj" in the above examples can be any object with RTTI.
//
// *****************************************************************************
// ANNONYMOUS EVENTS
// *****************************************************************************
//
// Instead of:
// obj.OnChange := MyObjectOnChange;
//
// You can now define event handlers inline with anonymous methods
// obj.OnChange := Events.Notify(procedure(Sender : TObject)
// begin
// DoSomethingHere();
// end);
//
// To release the memory used by the anonymous method, instead of setting the
// property to nil, you must release the event:
// Event.NotifyRelease(obj.OnChange);
//
// If the event is of a type that does not have an explicit helper, you can
// use the From method as follows:
// TKeyEventReference = reference to procedure(Sender: TObject; var Key: Word; Shift: TShiftState);
// obj.OnKeyUp := Events.From<TKeyEvent, TKeyEventReference>(procedure(Sender: TObject; var Key: Word; Shift: TShiftState)
// begin
// DoSomethingHere();
// end);
//
// *****************************************************************************
// LICENSE
// *****************************************************************************
//
// The MIT License (MIT)
// Copyright (c) 2012 by Sivv LLC, All Rights Reseved
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
// *****************************************************************************
// RELEASE NOTES
// *****************************************************************************
// 2014-07-07 : R6 Jason Southwell
// + XE6 & AppMethod Support
// + Firemonkey Desktop & Mobile Support
// + Overloaded Method support
// * Minor Performance Improvements
// * Several bug fixes
// 2012-06-14 : R4 Jason Southwell
// * implemented duck<I> overload to allow duck typing to a
// specified interface and assume the implementation.
// 2012-02-17 : R3 Jason Southwell
// + Added asA<I> to return a custom variant wrapper around the
// object allowing it to be called as though it were the
// interface supplied without using the duck interface methods.
// allowing you to see if the object has all of the methods
// and properties required of the interface even if it
// doesn't implement the interface.
// + Added impersonates<I> check to the object class helper
// allowing you to see if the object has all of the methods
// and properties required of the interface even if it
// doesn't implement the interface.
// + Added several overloads to better support indexed properties
// + Added eachProperty and eachMethod iterators to the TRTTI
// class.
// + Added selector comparisson functions, equalTo, notEqualTo,
// moreThan, and lessThan.
// + Added new duck functions to return selectors including:
// this (the same object via selector), related (all related
// objects, note that this is the same as "all" used to be),
// props (all object properties of the object), go (executes
// a method and returns a selector of the result.
// * Altered duck.all to return all related objects as well as
// any properties of type TObject.
// + Added new selector functions First, Last, Middle, Even, Odd
// which return new selectors filtered accordingly.
// + Added new selector function "use" which alters the current
// context of the selector.
// + Added new selector action function "replace" which alters
// the value of a property only if it matches the value
// supplied
// + Added new duck procedure "replace" which altersthe value
// of a property only if it matches the value supplied
// * Fixed isa. It's implementation had gone missing.
// * Renamed parameters in TRTTI from ctrl to obj. ctrl was a
// holdover from when the class was written to work only on
// TControl descendants and no longer made sense.
// * Changed all methods called "sett" to "setTo" due to Nick
// Hodges consistent badgering and the overwheming will
// demonstrated by a very scientific facebook poll.
// + Added new setTo functions on Selector and Duck to allow
// setting of multiple properties via TPropValue array.
// + Added new asValue class method to TRTTI to simplify
// convertion to TValue where needed.
// + Started documenting TRTTI class
// 2012-02-15 : R2 Jason Southwell
// + Added "each" method to ISelector allowing an anonymous
// method to be called for each object in the selector.
// Example:
// Form1.duck.each(procedure(obj : TObject)
// begin
// obj.duck.setTo('hint','This is the new hint');
// end);
// + Added "filter" method to ISelector allowing an anonymous
// method to be called for each object in the selector which
// is used to reduce the objects in the filter. Return True
// to include the item in the resulting selector.
// Example:
// Form1.duck.filter(function(obj : TObject) : boolean
// begin
// result := (obj.tag = 1) and SomeGlobalVariable;
// end).SetTo('Visible',False);
// + Added "on" method to ISelector which returns a new slector
// filled with the results of the object property specfied.
// Example:
// duck.all.on('Font').setTo('Color',clRed).setTo('Size',18);
// 2012-02-14 : R1 Jason Southwell
// + Initial Release to Open Source under MIT license
// *****************************************************************************
interface
uses System.SysUtils, System.Classes, System.Types, System.Rtti, System.TypInfo,
System.Generics.Collections, System.Variants;
{$SCOPEDENUMS ON}
type
TNotifyReference = TProc<TObject>;
PInterface = ^IInterface;
IImpersonated = Variant;
TRTTI = class
public
/// <summary>
/// Comapres two TValue variables to determine if they are the same value
/// of the same type.
/// </summary>
/// <param name="Value1">
/// First Value to compare
/// </param>
/// <param name="Value2">
/// Second Value to compare
/// </param>
/// <returns>
/// True if the two values represent the same value of the same type.
/// False if they do not.
/// </returns>
class function isSame(const Value1, Value2 : TValue) : boolean; overload; static;
class function isSame(const Params1, Params2: TArray<TRttiParameter>) : boolean; overload; static;
/// <summary>
/// Checks an object's property to determine if it is of the specified
/// type.
/// </summary>
/// <typeparam name="T">
/// The type to check against
/// </typeparam>
/// <param name="obj">
/// The object which has the property to test
/// </param>
/// <param name="PropertyName">
/// The property name which to test
/// </param>
/// <returns>
/// Returns true if the specified property exists on the object and if it
/// is of the specified type. Returns false if either it does not exist
/// or if it is not of the type.
/// </returns>
/// <remarks>
/// <para>
/// TRTTI.isA<boolean>(Edit1,'Visible') = True
/// </para>
/// <para>
/// TRTTI.isA<string>(Edit1,'Visible') = False
/// </para>
/// </remarks>
class function isA<T>(obj: TObject; const PropertyName: string) : boolean; overload; static;
/// <summary>
/// Returns a typed value from the specifed property on the supplied
/// object
/// </summary>
/// <typeparam name="T">
/// The type of the property which you will be returning
/// </typeparam>
/// <param name="obj">
/// The object from which to return the specified property
/// </param>
/// <param name="PropertyName">
/// The property name you wish to return
/// </param>
/// <returns>
/// The value of the property on the specified object
/// </returns>
/// <remarks>
/// <para>
/// TRTTI.get<boolean>(Edit1,'Visible') = true or false
/// </para>
/// <para>
/// if the property does not exist on the specified object, the value
/// returned would be the typecasted value of 0 or nil.
/// </para>
/// </remarks>
class function get<T>(obj: TObject; const PropertyName: string) : T; overload; static;
class function field<T>(obj: TObject; const FieldName : string) : T; static;
/// <summary>
/// Attempts to return a typed value from the specifed property on the
/// supplied object
/// </summary>
/// <typeparam name="T">
/// The type of the property which you will be returning
/// </typeparam>
/// <param name="obj">
/// The object from which to return the specified property
/// </param>
/// <param name="PropertyName">
/// The property name you wish to return
/// </param>
/// <param name="AResult">
/// The value of the property to be returned.
/// </param>
/// <returns>
/// True if the property was able to be returned, False if it was not.
/// </returns>
/// <remarks>
/// <para>
/// TRTTI.tryGet<boolean>(Edit1,'Visible',bIsVisible) = true or
/// false
/// </para>
/// <para>
/// if the property does not exist on the specified object, the value
/// returned from the function would be false. bIsVisible would hold
/// the value of the returned property.
/// </para>
/// </remarks>
class function tryGet<T>(obj: TObject; const PropertyName: string; var AResult : T) : boolean; overload; static;
/// <summary>
/// Sets a typed value to the specifed property on the supplied object
/// </summary>
/// <typeparam name="T">
/// The type of the property which you will be setting
/// </typeparam>
/// <param name="obj">
/// The object on which to set the specified property
/// </param>
/// <param name="PropertyName">
/// The property name you wish to set
/// </param>
/// <param name="Value">
/// The value to set to the property
/// </param>
/// <remarks>
/// This procedure fails silently if the property was unable to be set.
/// </remarks>
class procedure setTo<T>(obj: TObject; const PropertyName: string; Value: T); overload; static;
/// <summary>
/// Attempts to set a typed value to the specifed property on the
/// supplied object
/// </summary>
/// <typeparam name="T">
/// The type of the property which you will be setting
/// </typeparam>
/// <param name="obj">
/// The object on which to set the specified property
/// </param>
/// <param name="PropertyName">
/// The property name you wish to set
/// </param>
/// <param name="Value">
/// The value to set to the property.
/// </param>
/// <returns>
/// True if the property was able to be set, False if it was not.
/// </returns>
/// <remarks>
/// <para>
/// TRTTI.trySet<boolean>(Edit1,'Visible',bIsVisible) = true or
/// false
/// </para>
/// <para>
/// if the property does not exist on the specified object, or if bIsVisible was unable to be set to the Visible property, the valuereturned from the function would be false.
/// </para>
/// </remarks>
class function trySet<T>(obj: TObject; const PropertyName: string; Value: T) : boolean; overload; static;
class function isA<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>) : boolean; overload; static;
class function get<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>) : T; overload; static;
class function tryGet<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>; var AResult : T) : boolean; overload; static;
class procedure setTo<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>; Value: T); overload; static;
class function trySet<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>; Value: T) : boolean; overload; static;
class function asValue<T>(Value : T) : TValue;
class function getValue(obj: TObject; const PropertyName: string) : TValue; overload; static;
class function getValue(obj: TObject; const PropertyName: string; args : TArray<TValue>) : TValue; overload; static;
class procedure setValue(obj: TObject; const PropertyName: string; Value : TValue); overload; static;
class procedure setValue(obj: TObject; const PropertyName: string; args : TArray<TValue>; Value : TValue); overload; static;
class function call(obj : TObject; const MethodName : string; args : TArray<TValue>) : TValue;
class function tryCall(obj : TObject; const MethodName : string; args : TArray<TValue>; var AResult : TValue) : boolean;
class function isProperty(obj: TObject; const PropertyName: string) : boolean; overload; static;
class function isProperty(pti : PTypeInfo; const PropertyName: string) : boolean; overload; static;
class function isProperty(obj: TObject; const PropertyName: string; OfType : TClass) : boolean; overload; static;
class function isProperty(pti : PTypeInfo; const PropertyName: string; OfType : TClass) : boolean; overload; static;
class function isMethod(obj: TObject; const MethodName: string) : boolean; overload; static;
class function isMethod(pti : PTypeInfo; const MethodName: string) : boolean; overload; static;
class function isMethod(obj: TObject; const MethodName: string; Params : TArray<TRTTIParameter>) : boolean; overload; static;
class function isMethod(pti : PTypeInfo; const MethodName: string; Params : TArray<TRTTIParameter>) : boolean; overload; static;
class function isMethod(obj: TObject; const MethodName: string; Params : TArray<TRTTIParameter>; Returns : TRTTIType) : boolean; overload; static;
class function isMethod(pti : PTypeInfo; const MethodName: string; Params : TArray<TRTTIParameter>; Returns : TRTTIType) : boolean; overload; static;
class function exists(obj: TObject; const name: string) : boolean; overload; static;
class function exists(pti : PTypeInfo; const name: string) : boolean; overload; static;
class procedure eachProperty(obj : TObject; proc : TProc<TRTTIProperty>); overload;
class procedure eachProperty(pti : PTypeInfo; proc : TProc<TRTTIProperty>); overload;
class procedure eachMethod(obj : TObject; proc : TProc<TRTTIMethod>); overload;
class procedure eachMethod(pti : PTypeInfo; proc : TProc<TRTTIMethod>); overload;
class procedure eachProperty(obj : TObject; proc : TFunc<TRTTIProperty, boolean>); overload;
class procedure eachProperty(pti : PTypeInfo; proc : TFunc<TRTTIProperty, boolean>); overload;
class procedure eachMethod(obj : TObject; proc : TFunc<TRTTIMethod, boolean>); overload;
class procedure eachMethod(pti : PTypeInfo; proc : TFunc<TRTTIMethod, boolean>); overload;
end;
TEvent = class
private
FEvents : TDictionary<TPair<Pointer,Pointer>,IInterface>;
protected
procedure MakeEvent(const ameth; var evt); virtual;
procedure ParseMethod(const meth; var p1, p2 : Pointer); virtual;
function IsSameEvent(const ameth; const evt) : boolean; virtual;
public
constructor Create; virtual;
destructor Destroy; override;
function From<TEvent, TReference>(proc: TReference): TEvent;
procedure ReleaseAndNil<TEvent>(var event : TEvent);
procedure Release<TEvent>(event : TEvent);
function Notify(proc : TNotifyReference) : TNotifyEvent; virtual;
procedure NotifyRelease(event : TNotifyEvent); virtual;
end;
TPropValue = record
PropertyName : string;
Value: TValue;
constructor Create(const APropertyName : string; const AValue: TValue);
end;
ISelector = interface(IInterface)
// chained selection refinement methods
function has(PropertyName : string) : ISelector; overload;
function has(PropertyNames : TArray<string>) : ISelector; overload;
function has(NameValues : TArray<TPropValue>) : ISelector; overload;
function has(PropertyName : string; Value : TValue) : ISelector; overload;
function can(MethodName : string) : ISelector; overload;
function can(methodName : string; Params : TArray<TRttiParameter>) : ISelector; overload;
function can(methodName : string; Params : TArray<TRttiParameter>; Returns : TRttiType) : ISelector; overload;
function isa(ClassType : TClass) : ISelector;
function &on(PropertyName : string) : ISelector;
function first(Cnt : integer) : ISelector; overload;
function first : ISelector; overload;
function last(Cnt : integer) : ISelector; overload;
function last : ISelector; overload;
function middle(Idx, Cnt : integer) : ISelector;
function even : ISelector;
function odd : ISelector;
function use(Context : string) : ISelector;
// retrieves items enumerator
function count : integer;
function items : TArray<TObject>;
// Property Actions upon the entire selection
function setTo(Value : TValue) : ISelector; overload;
function setTo(propertyName : string; Value : TValue) : ISelector; overload;
function setTo(NameValues : TArray<TPropValue>) : ISelector; overload;
function replace(Find : TValue; Replace : TValue) : ISelector; overload;
function replace(propertyName : string; Find : TValue; Replace : TValue) : ISelector; overload;
function add(Value : TValue) : ISelector; overload;
function add(propertyName : string; Value : TValue) : ISelector; overload;
function subtract(Value : TValue) : ISelector; overload;
function subtract(propertyName : string; Value : TValue) : ISelector; overload;
function notEqualTo(Value : TValue) : ISelector; overload;
function notEqualTo(propertyName : string; Value : TValue) : ISelector; overload;
function equalTo(Value : TValue) : ISelector; overload;
function equalTo(propertyName : string; Value : TValue) : ISelector; overload;
function moreThan(Value : TValue) : ISelector; overload;
function moreThan(propertyName : string; Value : TValue) : ISelector; overload;
function lessThan(Value : TValue) : ISelector; overload;
function lessThan(propertyName : string; Value : TValue) : ISelector; overload;
// Method Actions upon the entire selection
function go : ISelector; overload;
function go(methodName : string) : ISelector; overload;
function go(args : TArray<TValue>) : ISelector; overload;
function go(methodName : string; args : TArray<TValue>) : ISelector; overload;
function call : TArray<TValue>; overload;
function call(methodName : string) : TArray<TValue>; overload;
function call(args : TArray<TValue>) : TArray<TValue>; overload;
function call(args : array of variant) : TArray<TValue>; overload;
function call(methodName : string; args : TArray<TValue>) : TArray<TValue>; overload;
function call(methodName : string; args : array of Variant; var AResult : TValue) : TArray<TValue>; overload;
function each(method : TProc<TObject>) : ISelector; overload;
function filter(method : TFunc<TObject,boolean>) : ISelector;
end;
IDuck = interface;
TInterceptBeforeFunc = reference to procedure(Args : TArray<TValue>; var Return : TValue; var Continue : boolean);
TInterceptAfterFunc = reference to procedure(Args : TArray<TValue>; var Return : TValue);
TInterceptBeforeProc = reference to procedure(Args : TArray<TValue>; var Continue : boolean);
TInterceptAfterProc = reference to procedure(Args : TArray<TValue>);
TInterceptExceptionProc = reference to procedure(E : Exception; Args : TArray<TValue>; var Return : TValue; var RaiseException : boolean);
IIntercept = interface
function before(proc : TInterceptBeforeProc) : IIntercept; overload;
function before(proc : TInterceptAfterProc) : IIntercept; overload;
function before(proc : TInterceptBeforeFunc) : IIntercept; overload;
function before(proc : TInterceptAfterFunc) : IIntercept; overload;
function after(proc : TInterceptAfterProc) : IIntercept; overload;
function after(proc : TInterceptAfterFunc) : IIntercept; overload;
function exception(proc : TInterceptExceptionProc) : IIntercept;
function abort : IIntercept;
function skip : IIntercept;
end;
IDuck = interface
procedure setTo(propertyName : string; Value : TValue); overload;
procedure setTo(NameValues : TArray<TPropValue>); overload;
procedure replace(propertyName : string; Find : TValue; Replace : TValue);
function get(propertyName : string) : TValue; overload;
function get(propertyName : string; OfType : TClass) : TValue; overload;
function has(propertyName : string) : boolean; overload;
function has(propertyName : string; OfType : TClass) : boolean; overload;
function can(methodName : string) : boolean; overload;
function can(methodName : string; Params : TArray<TRttiParameter>) : boolean; overload;
function can(methodName : string; Params : TArray<TRttiParameter>; Returns : TRttiType) : boolean; overload;
function call(methodName : string) : TValue; overload;
function call(methodName : string; args : TArray<TValue>) : TValue; overload;
function call(methodName : string; args : array of variant) : TValue; overload;
function call(methodName : string; var Exists : boolean) : TValue; overload;
function call(methodName : string; args : TArray<TValue>; var Exists : boolean) : TValue; overload;
function call(methodName : string; args : array of Variant; var Exists : boolean) : TValue; overload;
function call(methodName : string; var AResult : TValue) : boolean; overload;
function call(methodName : string; args : TArray<TValue>; var AResult : TValue) : boolean; overload;
function call(methodName : string; args : array of Variant; var AResult : TValue) : boolean; overload;
function go(methodName : string) : ISelector; overload;
function go(methodName : string; args : TArray<TValue>) : ISelector; overload;
function all : ISelector;
function props : ISelector;
function related : ISelector;
function this : ISelector;
function obj : TObject;
function intercept(methodName : string) : IIntercept;
end;
TSoftInterface<I: IInterface> = class(TVirtualInterface)
private
FSource : TObject;
public
constructor Create(Source : TObject);
procedure DoInvoke(Method : TRttiMethod; const Args : TArray<TValue>; out Result : TValue);
end;
TDuckHelper = class helper for TObject
public
function duck : IDuck; overload;
// this should be under IDuck, but interfaces don't currently support generic methods.
function impersonates<Intf> : boolean;
function asA<Intf> : IImpersonated;
function duck<I : IInterface> : TSoftInterface<I>; overload;
end;
TDuck = class(TObject)
public
function duck : IDuck; overload;
// this should be under IDuck, but interfaces don't currently support generic methods.
function impersonates<Intf> : boolean;
function asA<Intf> : IImpersonated;
function duck<I : IInterface> : TSoftInterface<I>; overload;
end;
TDuckVarData = packed record
VType : TVarType;
VDuck : IDuck;
VIType : PTypeInfo;
Reserved1: LongInt;
Reserved2 : WordBool;
end;
type
TDuckVariantType = class(TInvokeableVariantType)
protected
procedure DispInvoke(Dest: PVarData; [Ref] const Source: TVarData;
CallDesc: PCallDesc; Params: Pointer); override;
public
procedure Clear(var V: TVarData); override;
procedure Copy(var Dest: TVarData; const Source: TVarData;
const Indirect: Boolean); override;
end;
var
DuckVariant : TDuckVariantType;
var
Event : TEvent;
function PV(const APropertyName : string; const AValue : TValue) : TPropValue;
procedure RegisterPropertyEnumerator(const IndexedProperty : string; const CountProperty : string);
function DuckVarType : TVarType;
function VarIsDuck(const AValue : Variant) : Boolean;
function VarAsDuck(const AValue : Variant) : IImpersonated;
resourcestring
S_MISSINGCONTEXT = 'Context missing for opperation on selector. Try explicitly stating identifier in call to method or call "use" to specify context.';
implementation
uses
System.SysConst;
type
TSelectorImpl = class(TInterfacedObject, ISelector)
private
FResults : TList<TObject>;
FObject : TObject;
FContext : string;
protected
procedure RequireContext;
public
constructor Create(AObject : TObject; AContext : string; AResults : TList<TObject>); virtual;
destructor Destroy; override;
// chained selection refinement methods
function has(PropertyName : string) : ISelector; overload;
function has(PropertyNames : TArray<string>) : ISelector; overload;
function has(NameValues : TArray<TPropValue>) : ISelector; overload;
function has(PropertyName : string; Value : TValue) : ISelector; overload;
function can(MethodName : string) : ISelector; overload;
function can(methodName : string; Params : TArray<TRttiParameter>) : ISelector; overload;
function can(methodName : string; Params : TArray<TRttiParameter>; Returns : TRttiType) : ISelector; overload;
function isa(ClassType : TClass) : ISelector;
function &on(PropertyName : string) : ISelector;
function first(Cnt : integer) : ISelector; overload;
function first : ISelector; overload;
function last(Cnt : integer) : ISelector; overload;
function last : ISelector; overload;
function middle(Idx, Cnt : integer) : ISelector;
function even : ISelector;
function odd : ISelector;
function use(Context : string) : ISelector;
// retrieves items array
function count : integer;
function items : TArray<TObject>;
// Property Actions upon the entire selection
function setTo(Value : TValue) : ISelector; overload;
function setTo(NameValues : TArray<TPropValue>) : ISelector; overload;
function setTo(propertyName : string; Value : TValue) : ISelector; overload;
function replace(Find : TValue; Replace : TValue) : ISelector; overload;
function replace(propertyName : string; Find : TValue; Replace : TValue) : ISelector; overload;
function add(Value : TValue) : ISelector; overload;
function add(propertyName : string; Value : TValue) : ISelector; overload;
function subtract(Value : TValue) : ISelector; overload;
function subtract(propertyName : string; Value : TValue) : ISelector; overload;
function notEqualTo(Value : TValue) : ISelector; overload;
function notEqualTo(propertyName : string; Value : TValue) : ISelector; overload;
function equalTo(Value : TValue) : ISelector; overload;
function equalTo(propertyName : string; Value : TValue) : ISelector; overload;
function moreThan(Value : TValue) : ISelector; overload;
function moreThan(propertyName : string; Value : TValue) : ISelector; overload;
function lessThan(Value : TValue) : ISelector; overload;
function lessThan(propertyName : string; Value : TValue) : ISelector; overload;
// Method Actions upon the entire selection
function go : ISelector; overload;
function go(methodName : string) : ISelector; overload;
function go(args : TArray<TValue>) : ISelector; overload;
function go(methodName : string; args : TArray<TValue>) : ISelector; overload;
function call : TArray<TValue>; overload;
function call(methodName : string) : TArray<TValue>; overload;
function call(args : TArray<TValue>) : TArray<TValue>; overload;
function call(args : array of variant) : TArray<TValue>; overload;
function call(methodName : string; args : TArray<TValue>) : TArray<TValue>; overload;
function call(methodName : string; args : array of Variant; var AResult : TValue) : TArray<TValue>; overload;
function each(method : TProc<TObject>) : ISelector; overload;
function filter(method : TFunc<TObject,boolean>) : ISelector;
end;
TDuckImpl = class(TInterfacedObject, IDuck)
private
FOwner : TObject;
function IndexParam(idx : integer) : TArray<TValue>;
public
constructor Create(AOwner: TObject); virtual;
procedure EnumerateAssociatedObjects(AOwner : TObject; List : TList<TObject>); virtual;
procedure EnumerateObjectProperties(AOwner : TObject; List : TList<TObject>); virtual;
// IDuck
procedure setTo(propertyName : string; Value : TValue); overload;
procedure setTo(NameValues : TArray<TPropValue>); overload;
procedure replace(propertyName : string; Find : TValue; Replace : TValue);
function get(propertyName : string) : TValue; overload;
function get(propertyName : string; OfType : TClass) : TValue; overload;
function has(propertyName : string) : boolean; overload;
function has(propertyName : string; OfType : TClass) : boolean; overload;
function can(methodName : string) : boolean; overload;
function can(methodName : string; Params : TArray<TRttiParameter>) : boolean; overload;
function can(methodName : string; Params : TArray<TRttiParameter>; Returns : TRttiType) : boolean; overload;
function go(methodName : string) : ISelector; overload;
function go(methodName : string; args : TArray<TValue>) : ISelector; overload;
function call(methodName : string) : TValue; overload;
function call(methodName : string; args : TArray<TValue>) : TValue; overload;
function call(methodName : string; args : array of variant) : TValue; overload;
function call(methodName : string; var Exists : boolean) : TValue; overload;
function call(methodName : string; args : TArray<TValue>; var Exists : boolean) : TValue; overload;
function call(methodName : string; args : array of Variant; var Exists : boolean) : TValue; overload;
function call(methodName : string; var AResult : TValue) : boolean; overload;
function call(methodName : string; args : TArray<TValue>; var AResult : TValue) : boolean; overload;
function call(methodName : string; args : array of Variant; var AResult : TValue) : boolean; overload;
function intercept(methodName: string): IIntercept;
function obj : TObject;
function all : ISelector;
function props : ISelector;
function related : ISelector;
function this : ISelector;
end;
TInterceptImpl = class(TInterfacedObject, IIntercept)
type
TInterceptInfo = class
private
FImpl: TMethodImplementation;
FOriginalCode: Pointer;
FProxyCode: Pointer;
FMethod: TRttiMethod;
public
constructor Create(AOriginalCode: Pointer; AMethod: TRttiMethod;
const ACallback: TMethodImplementationCallback);
destructor Destroy; override;
property OriginalCode: Pointer read FOriginalCode;
property ProxyCode: Pointer read FProxyCode;
property Method: TRttiMethod read FMethod;
end;
private
FContext: TRttiContext;
FDuck : IDuck;
FDoBeforeFunc : TInterceptBeforeFunc;
FDoBeforeSimpleFunc : TInterceptAfterFunc;
FDoBefore : TInterceptBeforeProc;
FDoBeforeSimple : TInterceptAfterProc;
FDoAfter : TInterceptAfterProc;
FDoAfterFunc : TInterceptAfterFunc;
FDoExcept : TInterceptExceptionProc;
FObject : TObject;
FMethodName : string;
FImplementationCallback: TMethodImplementationCallback;
FOriginalClass: TClass;
FIntercept: TInterceptInfo;
FProxyClassData: Pointer;
FProxyClass: TClass;
procedure RawCallback(UserData: Pointer; const Args: TArray<TValue>;
out Result: TValue);
public
constructor Create(ADuck : IDuck; AObject : TObject; AMethodName : string);
destructor Destroy; override;
function before(proc : TInterceptBeforeProc) : IIntercept; overload;
function before(proc : TInterceptAfterProc) : IIntercept; overload;
function before(proc : TInterceptBeforeFunc) : IIntercept; overload;
function before(proc : TInterceptAfterFunc) : IIntercept; overload;
function after(proc : TInterceptAfterProc) : IIntercept; overload;
function after(proc : TInterceptAfterFunc) : IIntercept; overload;
function exception(proc : TInterceptExceptionProc) : IIntercept;
function abort : IIntercept;
function skip : IIntercept;
end;
var
enumprops : TArray<TArray<string>>;
function DuckVarType : TVarType;
begin
Result := DuckVariant.VarType;
end;
function VarIsDuck(const AValue : Variant) : Boolean;
begin
Result := (TVarData(AValue).VType and varTypeMask) = DuckVarType;
end;
function VarAsDuck(const AValue : Variant) : IImpersonated;
begin
if not VarIsDuck(AValue) then
VarCast(Result,AValue,DuckVarType)
else
Result := AValue;
end;
function PV(const APropertyName : string; const AValue : TValue) : TPropValue;
begin
Result.Create(APropertyName, AValue);
end;
procedure RegisterPropertyEnumerator(const IndexedProperty : string; const CountProperty : string);
begin
setLength(enumprops,length(enumprops)+1);
setLength(enumprops[length(enumprops)-1],2);
enumprops[length(enumprops)-1][0] := IndexedProperty;
enumprops[length(enumprops)-1][1] := CountProperty;
end;
procedure InitializeEnumProps;
begin
RegisterPropertyEnumerator('Children','ChildCount');
RegisterPropertyEnumerator('Components','ComponentCount');
RegisterPropertyEnumerator('Items','Count');
RegisterPropertyEnumerator('Items','ItemCount');
RegisterPropertyEnumerator('Objects','Count');
RegisterPropertyEnumerator('Objects','ObjectCount');
RegisterPropertyEnumerator('Commands','CommandCount');
RegisterPropertyEnumerator('DataSets','Dataset');
RegisterPropertyEnumerator('Fields','FieldCount');
RegisterPropertyEnumerator('FieldDefs','FieldDefCount');
RegisterPropertyEnumerator('IndexFields','IndexFieldCount');
RegisterPropertyEnumerator('Errors','ErrorCount');
RegisterPropertyEnumerator('Sessions','SessionCount');
RegisterPropertyEnumerator('Databases','DatabaseCount');
RegisterPropertyEnumerator('BindComps','BindCompCount');
RegisterPropertyEnumerator('Nodes','NodeCount');
RegisterPropertyEnumerator('Forms','FormCount');
RegisterPropertyEnumerator('DataModules','DataModuleCount');
RegisterPropertyEnumerator('Columns','ColumnCount');
RegisterPropertyEnumerator('ListItems','Count');
RegisterPropertyEnumerator('Printers','Count');
RegisterPropertyEnumerator('Points','Count');
RegisterPropertyEnumerator('Rows','RowCount');
end;
{ TSoftInterface<I> }
constructor TSoftInterface<I>.Create(Source : TObject);
begin
FSource := Source;
inherited Create(TypeInfo(I), DoInvoke);
end;
procedure TSoftInterface<I>.DoInvoke(Method: TRttiMethod;
const Args: TArray<TValue>; out Result: TValue);
var
ary : TArray<TValue>;
i : integer;
begin
SetLength(ary,Length(Args)-1);
for i := 1 to length(args)-1 do
ary[i-1] := Args[i];
Result := TRTTI.call(FSource,Method.Name,ary);
end;
{ TRTTI }
class function TRTTI.call(obj: TObject; const MethodName: string; args: TArray<TValue>): TValue;
var
vResult : TValue;
bCalled : boolean;
begin
Result := nil;
bCalled := False;
vResult := TValue.Empty;
TRTTI.eachMethod(obj,function(m : TRTTIMethod) : boolean
var
params : TArray<TRTTIParameter>;
i : integer;
b : boolean;
begin
Result := True;
if (CompareText(m.Name,MethodName)=0) then
begin
params := m.GetParameters;
if length(params) = length(args) then
begin
b := True;
for i := 0 to Length(args)-1 do
begin
if args[i].TypeInfo^.Kind <> params[i].ParamType.TypeKind then
begin
b := false;
break;
end;
end;
if b then
begin
vResult := m.Invoke(obj,args);
Result := false;
bCalled := True;
end;
end;
end;
end);
if not bCalled then
raise EMethodNotFound.Create('Could not find method "'+MethodName+'" on Object of class "'+obj.ClassName+'"');
Result := vResult;
end;
class function TRTTI.get<T>(obj: TObject; const PropertyName: string): T;
var
cxt : TRTTIContext;
prop : TRttiProperty;
begin
Result := T(nil);
prop := cxt.GetType(obj.ClassInfo).GetProperty(PropertyName);
if prop <> nil then
begin
Result := prop.GetValue(obj).AsType<T>;
end;
end;
class function TRTTI.get<T>(obj: TObject; const PropertyName: string; args : TArray<TValue>): T;
var
cxt : TRTTIContext;
prop : TRttiIndexedProperty;
begin
Result := T(nil);
prop := cxt.GetType(obj.ClassInfo).GetIndexedProperty(PropertyName);
if prop <> nil then
begin
Result := prop.GetValue(obj, args).AsType<T>;
end;
end;
class function TRTTI.getValue(obj: TObject; const PropertyName: string): TValue;
var
cxt : TRTTIContext;
prop : TRttiProperty;
begin
Result := nil;
prop := cxt.GetType(obj.ClassInfo).GetProperty(PropertyName);
if prop <> nil then
begin
Result := prop.GetValue(obj);
end;
end;
class function TRTTI.getValue(obj: TObject; const PropertyName: string; args : TArray<TValue>) : TValue;
var
cxt : TRTTIContext;
prop : TRttiIndexedProperty;
begin
Result := nil;
prop := cxt.GetType(obj.ClassInfo).GetIndexedProperty(PropertyName);
if prop <> nil then
begin
Result := prop.GetValue(obj, args);
end;
end;
class function TRTTI.asValue<T>(Value : T) : TValue;
begin
Result := TValue.From<T>(Value);
end;
class function TRTTI.exists(obj: TObject; const Name: string): boolean;
begin
Result := isProperty(obj, Name) or isMethod(obj, Name);
end;
class function TRTTI.exists(pti : PTypeInfo; const Name: string): boolean;
begin
Result := isProperty(pti, Name) or isMethod(pti, Name);
end;
class function TRTTI.field<T>(obj: TObject; const FieldName: string): T;
var
cxt : TRTTIContext;
prop : TRttiField;
begin
Result := T(nil);
prop := cxt.GetType(obj.ClassInfo).GetField(FieldName);
if prop <> nil then
begin
Result := prop.GetValue(obj).AsType<T>;
end;
end;
class function TRTTI.isProperty(obj: TObject; const PropertyName: string): boolean;
var
cxt : TRTTIContext;
begin
Result := (cxt.GetType(obj.ClassInfo).GetProperty(PropertyName) <> nil) or
(cxt.GetType(obj.ClassInfo).GetIndexedProperty(PropertyName) <> nil);
end;
class function TRTTI.isProperty(pti : PTypeInfo; const PropertyName: string): boolean;
var
cxt : TRTTIContext;
begin
Result := (cxt.GetType(pti).GetProperty(PropertyName) <> nil) or
(cxt.GetType(pti).GetIndexedProperty(PropertyName) <> nil);
end;
class function TRTTI.isProperty(obj: TObject; const PropertyName: string; OfType : TClass): boolean;
var
cxt : TRTTIContext;
prop : TRttiMember;
begin
prop := cxt.GetType(obj.ClassInfo).GetProperty(PropertyName);
Result := (prop <> nil) and ((prop.ClassType = OfType) or prop.InheritsFrom(OfType));
if not Result then
begin
prop := cxt.GetType(obj.ClassInfo).GetIndexedProperty(PropertyName);
Result := (prop <> nil) and ((prop.ClassType = OfType) or prop.InheritsFrom(OfType));
end;
end;
class function TRTTI.isProperty(pti : PTypeInfo; const PropertyName: string; OfType : TClass): boolean;
var
cxt : TRTTIContext;
prop : TRttiMember;
begin
prop := cxt.GetType(pti).GetProperty(PropertyName);
Result := (prop <> nil) and ((prop.ClassType = OfType) or prop.InheritsFrom(OfType));
if not Result then
begin
prop := cxt.GetType(pti).GetIndexedProperty(PropertyName);
Result := (prop <> nil) and ((prop.ClassType = OfType) or prop.InheritsFrom(OfType));
end;
end;
class function TRTTI.isSame(const Value1, Value2: TValue): boolean;
begin
result :=