REST easy with kbmMW #24 使用kbmMW实现JSON/XML/YAML转换成对象

 你想过没有，把一个给定的xml或json生成一个Delphi类，并通过这个类完成对xml或json的读写操作吗？

不管有没有，现在kbmMW为我们实现了，看下面这行代码：

var
   s:string;
...
   s:=TkbmMWJSONMarshal.GenerateDelphiClassFromUTF8File('auctions.json','Unit2','JSONData');
...

{
"realm":{"name":"Aegwynn","slug":"aegwynn"},
"alliance":{"auctions":[
    {"auc":1972333274,"item":22574,"owner":"Schäuble","bid":51300,"buyout":54000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":30355200},
    {"auc":1970925966,"item":22446,"owner":"Aenni","bid":1890000,"buyout":2450000,"quantity":10,"timeLeft":"LONG","rand":0,"seed":1280052352},
    {"auc":1972187088,"item":82800,"owner":"Ainshu","bid":4329000,"buyout":4329000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":955897088,"petSpeciesId":122,"petBreedId":5,"petLevel":1,"petQualityId":2},
    {"auc":1972201216,"item":51950,"owner":"Ulath","bid":119157,"buyout":121590,"quantity":3,"timeLeft":"VERY_LONG","rand":0,"seed":1109650432},
... +60000 entries
]},
"horde":{"auctions":[
    {"auc":1970970808,"item":82952,"owner":"Guldarak","bid":4004290,"buyout":4004426,"quantity":1,"timeLeft":"LONG","rand":0,"seed":950078272},
    {"auc":1971973942,"item":4306,"owner":"Blutrabé","bid":94500,"buyout":99999,"quantity":20,"timeLeft":"VERY_LONG","rand":0,"seed":956528896},
    {"auc":1971973992,"item":4306,"owner":"Blutrabé","bid":94500,"buyout":99999,"quantity":20,"timeLeft":"VERY_LONG","rand":0,"seed":1476867968},
    {"auc":1972449149,"item":87893,"owner":"Thêlon","bid":2375000,"buyout":2500000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":848616448},
    {"auc":1971763986,"item":74705,"owner":"Gondoline","bid":15558129,"buyout":16662661,"quantity":1,"timeLeft":"LONG","rand":0,"seed":577727872},
... +2000 entries
]},
"neutral":{"auctions":[
    {"auc":1971600068,"item":72145,"owner":"Mellkore","bid":59990000,"buyout":59990000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":436886144},
    {"auc":1972336265,"item":8485,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336316,"item":8487,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336611,"item":8487,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336922,"item":8488,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336986,"item":8488,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1971335148,"item":76085,"owner":"Splatthy","bid":4418750,"buyout":4950000,"quantity":5,"timeLeft":"VERY_LONG","rand":0,"seed":2058173312},
    {"auc":1972336837,"item":8487,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336524,"item":8486,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1971335152,"item":76085,"owner":"Splatthy","bid":4418750,"buyout":4950000,"quantity":5,"timeLeft":"VERY_LONG","rand":0,"seed":2058173312},
    {"auc":1972336351,"item":8485,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972386885,"item":4338,"owner":"Huntez","bid":90284,"buyout":95038,"quantity":15,"timeLeft":"VERY_LONG","rand":0,"seed":944449152},
    {"auc":1971335163,"item":76085,"owner":"Splatthy","bid":17675000,"buyout":19800000,"quantity":20,"timeLeft":"VERY_LONG","rand":0,"seed":1033557888},
    {"auc":1972336774,"item":8487,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1971335155,"item":76085,"owner":"Splatthy","bid":4418750,"buyout":4950000,"quantity":5,"timeLeft":"VERY_LONG","rand":0,"seed":2058173312},
    {"auc":1972336383,"item":8485,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336563,"item":8486,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972386607,"item":12808,"owner":"Huntez","bid":71499,"buyout":79999,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":266490112},
    {"auc":1971335149,"item":76085,"owner":"Splatthy","bid":4418750,"buyout":4950000,"quantity":5,"timeLeft":"VERY_LONG","rand":0,"seed":2058173312},
    {"auc":1972336707,"item":8486,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972386682,"item":16249,"owner":"Huntez","bid":11250,"buyout":0,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":747154816},
    {"auc":1972386894,"item":4338,"owner":"Huntez","bid":90284,"buyout":95038,"quantity":15,"timeLeft":"VERY_LONG","rand":0,"seed":944449152},
    {"auc":1972337130,"item":8488,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0},
    {"auc":1972336425,"item":8485,"owner":"Zaruman","bid":351500,"buyout":450000,"quantity":1,"timeLeft":"VERY_LONG","rand":0,"seed":0}]}
}

一行代码，把给定的JSON文件，生成对应的类单元，类名为TJSONData。

将上面的s变量，存在文件，就得到了生成的单元，加入到自己的项目中，就可以通过TJSONData类来访问对应的auctions.json中的内容了！

下面是生成的内容：

unit Unit2;

// ==========================================================================
// Generated by kbmMW ObjectNotation marshalling converter
// 11/03/2019 00:07:12
// ==========================================================================

interface

uses
   Classes,
   Generics.Collections,
   kbmMWRTTI,
   kbmMWObjectMarshal,
   kbmMWDateTime,
   kbmMWNullable;

type

   TJSONData=class;
   Trealm=class;
   Talliance=class;
   TauctionsList=class;
   Tauctions=class;
   Thorde=class;
   Tneutral=class;
   [kbmMW_Root('TJSONData',[mwrfIncludeOnlyTagged])]
   TJSONData=class
   private
      Frealm:Trealm;
      Falliance:Talliance;
      Fhorde:Thorde;
      Fneutral:Tneutral;
   protected
      procedure Setrealm(const AValue:Trealm); virtual;
      procedure Setalliance(const AValue:Talliance); virtual;
      procedure Sethorde(const AValue:Thorde); virtual;
      procedure Setneutral(const AValue:Tneutral); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('realm')]
      property realm:Trealm read Frealm write Setrealm;

      [kbmMW_Element('alliance')]
      property alliance:Talliance read Falliance write Setalliance;

      [kbmMW_Element('horde')]
      property horde:Thorde read Fhorde write Sethorde;

      [kbmMW_Element('neutral')]
      property neutral:Tneutral read Fneutral write Setneutral;
   end;

   [kbmMW_Root('realm',[mwrfIncludeOnlyTagged])]
   Trealm=class
   private
      Fname:kbmMWNullable<string>;
      Fslug:kbmMWNullable<string>;
   public
      [kbmMW_Element('name')]
      property name:kbmMWNullable<string> read Fname write Fname;

      [kbmMW_Element('slug')]
      property slug:kbmMWNullable<string> read Fslug write Fslug;
   end;

   [kbmMW_Root('alliance',[mwrfIncludeOnlyTagged])]
   Talliance=class
   private
      Fauctions:TauctionsList;
   protected
      procedure Setauctions(const AValue:TauctionsList); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('auctions')]
      property auctions:TauctionsList read Fauctions write Setauctions;
   end;

   [kbmMW_Child('auctions',[mwcfFlatten])]
   TauctionsList=class(TObjectList<Tauctions>);
   [kbmMW_Root('auctions',[mwrfIncludeOnlyTagged])]
   Tauctions=class
   private
      FpetSpeciesId:kbmMWNullable<double>;
      FpetBreedId:kbmMWNullable<double>;
      FpetLevel:kbmMWNullable<double>;
      FpetQualityId:kbmMWNullable<double>;
      Fauc:kbmMWNullable<double>;
      Fitem:kbmMWNullable<double>;
      Fowner:kbmMWNullable<string>;
      Fbid:kbmMWNullable<double>;
      Fbuyout:kbmMWNullable<double>;
      Fquantity:kbmMWNullable<double>;
      FtimeLeft:kbmMWNullable<string>;
      Frand:kbmMWNullable<double>;
      Fseed:kbmMWNullable<double>;
   public
      [kbmMW_Element('petSpeciesId')]
      property petSpeciesId:kbmMWNullable<double> read FpetSpeciesId write FpetSpeciesId;

      [kbmMW_Element('petBreedId')]
      property petBreedId:kbmMWNullable<double> read FpetBreedId write FpetBreedId;

      [kbmMW_Element('petLevel')]
      property petLevel:kbmMWNullable<double> read FpetLevel write FpetLevel;

      [kbmMW_Element('petQualityId')]
      property petQualityId:kbmMWNullable<double> read FpetQualityId write FpetQualityId;

      [kbmMW_Element('auc')]
      property auc:kbmMWNullable<double> read Fauc write Fauc;

      [kbmMW_Element('item')]
      property item:kbmMWNullable<double> read Fitem write Fitem;

      [kbmMW_Element('owner')]
      property owner:kbmMWNullable<string> read Fowner write Fowner;

      [kbmMW_Element('bid')]
      property bid:kbmMWNullable<double> read Fbid write Fbid;

      [kbmMW_Element('buyout')]
      property buyout:kbmMWNullable<double> read Fbuyout write Fbuyout;

      [kbmMW_Element('quantity')]
      property quantity:kbmMWNullable<double> read Fquantity write Fquantity;

      [kbmMW_Element('timeLeft')]
      property timeLeft:kbmMWNullable<string> read FtimeLeft write FtimeLeft;

      [kbmMW_Element('rand')]
      property rand:kbmMWNullable<double> read Frand write Frand;

      [kbmMW_Element('seed')]
      property seed:kbmMWNullable<double> read Fseed write Fseed;
   end;

   [kbmMW_Root('horde',[mwrfIncludeOnlyTagged])]
   Thorde=class
   private
      Fauctions:TauctionsList;
   protected
      procedure Setauctions(const AValue:TauctionsList); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('auctions')]
      property auctions:TauctionsList read Fauctions write Setauctions;
   end;

   [kbmMW_Root('neutral',[mwrfIncludeOnlyTagged])]
   Tneutral=class
   private
      Fauctions:TauctionsList;
   protected
      procedure Setauctions(const AValue:TauctionsList); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('auctions')]
      property auctions:TauctionsList read Fauctions write Setauctions;
   end;


implementation

procedure TJSONData.Setrealm(const AValue:Trealm);
begin
     if Assigned(Frealm) then
        Frealm.Free;
     Frealm:=AValue;
end;

procedure TJSONData.Setalliance(const AValue:Talliance);
begin
     if Assigned(Falliance) then
        Falliance.Free;
     Falliance:=AValue;
end;

procedure TJSONData.Sethorde(const AValue:Thorde);
begin
     if Assigned(Fhorde) then
        Fhorde.Free;
     Fhorde:=AValue;
end;

procedure TJSONData.Setneutral(const AValue:Tneutral);
begin
     if Assigned(Fneutral) then
        Fneutral.Free;
     Fneutral:=AValue;
end;

destructor TJSONData.Destroy;
begin
     Frealm.Free;
     Falliance.Free;
     Fhorde.Free;
     Fneutral.Free;
     inherited;
end;

procedure Talliance.Setauctions(const AValue:TauctionsList);
begin
     if Assigned(Fauctions) then
        Fauctions.Free;
     Fauctions:=AValue;
end;

destructor Talliance.Destroy;
begin
     Fauctions.Free;
     inherited;
end;

procedure Thorde.Setauctions(const AValue:TauctionsList);
begin
     if Assigned(Fauctions) then
        Fauctions.Free;
     Fauctions:=AValue;
end;

destructor Thorde.Destroy;
begin
     Fauctions.Free;
     inherited;
end;

procedure Tneutral.Setauctions(const AValue:TauctionsList);
begin
     if Assigned(Fauctions) then
        Fauctions.Free;
     Fauctions:=AValue;
end;

destructor Tneutral.Destroy;
begin
     Fauctions.Free;
     inherited;
end;


initialization
   kbmMWRegisterKnownClasses([TMainClass,Trealm,Talliance,TauctionsList,Tauctions,Thorde,Tneutral]);

end.

要实际读取文件，创建一个程序，将Unit2.pas添加到它，并编写以下代码：

procedure TForm1.Button1Click(Sender: TObject);
var
   m:TkbmMWCustomRTTIMarshal;
   o:TJSONData;
begin
     m:=TkbmMWJSONMarshal.Create;
     try
        TkbmMWJSONMarshal(m).AnonymousRoot:=true;
        o:=TkbmMWJSONMarshal(m).ValueFromUTF8File<TJSONData>('auctions.json');
        // Your complete parsed file is now contained in the object instance o.
     finally
        o.Free;
        m.Free;
     end;
end;

下面是一个xml文件：

<?xml version="1.0"?>
<root>
    <course>
        <reg_num>10577</reg_num>
        <subj>ANTH</subj>
        <crse>211</crse>
        <sect>F01</sect>
        <title>Introduction to Anthropology</title>
        <units>1.0</units>
        <instructor>Brightman</instructor>
        <days>M-W</days>
        <time>
            <start_time>03:10PM</start_time>
            <end_time>04:30</end_time>
        </time>
        <place>
            <building>ELIOT</building>
            <room>414</room>
        </place>
    </course>
    <course>
        <reg_num>20573</reg_num>
        <subj>ANTH</subj>
        <crse>344</crse>
        <sect>S01</sect>
        <title>Sex and Gender</title>
        <units>1.0</units>
        <instructor>Makley</instructor>
        <days>T-Th</days>
        <time>
            <start_time>10:30AM</start_time>
            <end_time>11:50</end_time>
        </time>
        <place>
            <building>VOLLUM</building>
            <room>120</room>
        </place>
    </course>
    <course>
        <reg_num>10624</reg_num>
        <subj>BIOL</subj>
        <crse>431</crse>
        <sect>F01</sect>
        <title>Field Biology of Amphibians</title>
        <units>0.5</units>
...
    </course>
...
</root>

把上面xml内容生成类的代码：

var
   s:string;
...
    s:=TkbmMWXMLMarshal.GenerateDelphiClassFromFile('courses.xml','Unit3','XMLData');
...

把s变成存为Unit3.pas文件：

unit Unit3;

// ==========================================================================
// Generated by kbmMW ObjectNotation marshalling converter
// 10/03/2019 23:54:52
// ==========================================================================

interface

uses
   Classes,
   Generics.Collections,
   kbmMWRTTI,
   kbmMWObjectMarshal,
   kbmMWDateTime,
   kbmMWNullable;

type

   Troot=class;
   TcourseList=class;
   Tcourse=class;
   Ttime=class;
   Tplace=class;
   [kbmMW_Root('root',[mwrfIncludeOnlyTagged])]
   Troot=class
   private
      Fcourse:TcourseList;
   protected
      procedure Setcourse(const AValue:TcourseList); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('course')]
      property course:TcourseList read Fcourse write Setcourse;
   end;

   [kbmMW_Child('course',[mwcfFlatten])]
   TcourseList=class(TObjectList<Tcourse>);
   [kbmMW_Root('course',[mwrfIncludeOnlyTagged])]
   Tcourse=class
   private
      Ftime:Ttime;
      Fplace:Tplace;
      Freg_num:kbmMWNullable<string>;
      Fsubj:kbmMWNullable<string>;
      Fcrse:kbmMWNullable<string>;
      Fsect:kbmMWNullable<string>;
      Ftitle:kbmMWNullable<string>;
      Funits:kbmMWNullable<string>;
      Finstructor:kbmMWNullable<string>;
      Fdays:kbmMWNullable<string>;
      Fxml_repository:kbmMWNullable<string>;
   protected
      procedure Settime(const AValue:Ttime); virtual;
      procedure Setplace(const AValue:Tplace); virtual;
   public
      destructor Destroy; override;

      [kbmMW_Element('time')]
      property time:Ttime read Ftime write Settime;

      [kbmMW_Element('place')]
      property place:Tplace read Fplace write Setplace;

      [kbmMW_Element('reg_num')]
      property reg_num:kbmMWNullable<string> read Freg_num write Freg_num;

      [kbmMW_Element('subj')]
      property subj:kbmMWNullable<string> read Fsubj write Fsubj;

      [kbmMW_Element('crse')]
      property crse:kbmMWNullable<string> read Fcrse write Fcrse;

      [kbmMW_Element('sect')]
      property sect:kbmMWNullable<string> read Fsect write Fsect;

      [kbmMW_Element('title')]
      property title:kbmMWNullable<string> read Ftitle write Ftitle;

      [kbmMW_Element('units')]
      property units:kbmMWNullable<string> read Funits write Funits;

      [kbmMW_Element('instructor')]
      property instructor:kbmMWNullable<string> read Finstructor write Finstructor;

      [kbmMW_Element('days')]
      property days:kbmMWNullable<string> read Fdays write Fdays;

      [kbmMW_Element('xml_repository')]
      property xml_repository:kbmMWNullable<string> read Fxml_repository write Fxml_repository;
   end;

   [kbmMW_Root('time',[mwrfIncludeOnlyTagged])]
   Ttime=class
   private
      Fstart_time:kbmMWNullable<string>;
      Fend_time:kbmMWNullable<string>;
   public
      [kbmMW_Element('start_time')]
      property start_time:kbmMWNullable<string> read Fstart_time write Fstart_time;

      [kbmMW_Element('end_time')]
      property end_time:kbmMWNullable<string> read Fend_time write Fend_time;
   end;

   [kbmMW_Root('place',[mwrfIncludeOnlyTagged])]
   Tplace=class
   private
      Fbuilding:kbmMWNullable<string>;
      Froom:kbmMWNullable<string>;
   public
      [kbmMW_Element('building')]
      property building:kbmMWNullable<string> read Fbuilding write Fbuilding;

      [kbmMW_Element('room')]
      property room:kbmMWNullable<string> read Froom write Froom;
   end;


implementation

procedure Troot.Setcourse(const AValue:TcourseList);
begin
     if Assigned(Fcourse) then
        Fcourse.Free;
     Fcourse:=AValue;
end;

destructor Troot.Destroy;
begin
     Fcourse.Free;
     inherited;
end;

procedure Tcourse.Settime(const AValue:Ttime);
begin
     if Assigned(Ftime) then
        Ftime.Free;
     Ftime:=AValue;
end;

procedure Tcourse.Setplace(const AValue:Tplace);
begin
     if Assigned(Fplace) then
        Fplace.Free;
     Fplace:=AValue;
end;

destructor Tcourse.Destroy;
begin
     Ftime.Free;
     Fplace.Free;
     inherited;
end;


initialization
   kbmMWRegisterKnownClasses([Troot,TcourseList,Tcourse,Ttime,Tplace]);

end.

读取和写入这个XML数据的Delphi代码:

procedure TForm1.Button2Click(Sender: TObject);
var
   m:TkbmMWCustomRTTIMarshal;
   o:Troot;
   s:string;
begin
     m:=TkbmMWXMLMarshal.Create;
     try
        o:=TkbmMWXMLMarshal(m).ValueFromFile<Troot>('courses.xml');
        // o now contains all courses.

        s:=TkbmMWXMLMarshal(m).ValueToString(o);
        // s now contains XML generated from o.
     finally
        o.Free;
        m.Free;
     end;
end;