javascript - 需要帮助在 SmartMobileStudio 中导入 NodeJS-Module "htmlparser2"

Question

我尝试在 SmartMobileStudio 中使用 htmlparser2 模块(通过 npm install htmlparser2 安装)。该模块本身在直接 javascript 中运行良好(使用来自 htmlparser2's Homepage 的稍微更改的示例):

var htmlparser = require("htmlparser2");
var parser = new htmlparser.Parser({
    onopentag: function(name, attribs){
        console.log(name);
        console.log(attribs);
    }
});
parser.write("<img src='image1.jpg'>");
parser.end();

使用 SMS (2.0.0.9 Beta) 我尝试像这样导入模块:

unit NodeJS.htmlparser2;

interface

uses
  NodeJS.Core,
  NodeJS.events;

type
  TOnTag = procedure(name: string; attribs: Variant);
  TOnText = procedure(text: string);

  JParser = class external(NodeJS.events.JNodeEventEmitter)
    procedure write(s: string);
    procedure &end;
  end;

  Jhtmlparser_Exports = class external
  public
    function Parser(onopentag: TOnTag; ontext: TOnText; onclosetag: TOnTag): JParser;
  end;

function htmlparser2: Jhtmlparser_Exports;

implementation

function htmlparser2: Jhtmlparser_Exports;
begin
  result := Jhtmlparser_Exports( require("htmlparser2") );
end;

end.

我像这样更改了 Node.js-New-Project-Template 生成的项目:

[...]

procedure TServer.Run;
begin
  var htmlparser := NodeJS.htmlparser2.htmlparser2;

  var parser := htmlparser.Parser(
   procedure (Name: string; Attribs: Variant)
   begin
     console_.log([Name]);
     console_.log([Attribs]);
   end,
   nil,
   nil);

  parser.write("<img src='image1.jpg'>");
  parser.end();
end;

问题是发出的代码不正确，但几乎:

[...]
parser = htmlparser.Parser(function (Name$3, Attribs) {
   console_().log([Name$3].slice());
   console_().log([Attribs].slice());
},null,null);
[...]

这个有效:

[...]
parser = new htmlparser.Parser({onopentag: function (Name$3, Attribs) {
   console_().log([Name$3].slice());
   console_().log([Attribs].slice());
}});
[...]

区别在于“new”关键字和命名事件回调“onpentag”。我需要编写什么来生成有效的 js 代码？

Answer 1

因为不能像使用 javascript 和 requirejs/nodejs 那样在 pascal 中“导出”类，所以我们需要使用外部类技巧:我们可以为外部类名设置一些代码。其次，我们需要提供一个“选项”对象(更冗长但需要类型安全)。

JParserOptions = class
  onopentag : TOnTag;
  ontext    : TOnText;
  onclosetag: TOnTag
end;

JParser = class external '(htmlparser2()).Parser' (NodeJS.events.JNodeEventEmitter)
  constructor Create(options: JParserOptions);

  procedure write(s: string);
  procedure &end;
end;

我们可以这样使用它:

var options = JParserOptions.Create;
options.onopentag := procedure (Name: string; Attribs: Variant)
  begin
    console_.log([Name]);
    console_.log([Attribs]);
  end;

var parser := new JParser(options);