javascript - 如何 Hook 库函数(Golden Layout)并调用其他方法

Question

我正在使用一个名为 Golden Layout 的库，它有一个名为 destroy 的函数，它将在窗口关闭或刷新时关闭所有应用程序窗口

我需要为 destroy 函数添加额外的方法。我还需要删除所有本地存储。

我该怎么做？请帮忙

下面是插件代码。

lm.LayoutManager = function( config, container ) {
....    
destroy: function() {
            if( this.isInitialised === false ) {
                return;
            }
            this._onUnload();
            $( window ).off( 'resize', this._resizeFunction );
            $( window ).off( 'unload beforeunload', this._unloadFunction );
            this.root.callDownwards( '_$destroy', [], true );
            this.root.contentItems = [];
            this.tabDropPlaceholder.remove();
            this.dropTargetIndicator.destroy();
            this.transitionIndicator.destroy();
            this.eventHub.destroy();

            this._dragSources.forEach( function( dragSource ) {
                dragSource._dragListener.destroy();
                dragSource._element = null;
                dragSource._itemConfig = null;
                dragSource._dragListener = null;
            } );
            this._dragSources = [];
        },

我可以像这样访问组件中的 destroy 方法

this.layout = new GoldenLayout(this.config, this.layoutElement.nativeElement);

this.layout.destroy();`

我的代码

@HostListener('window:beforeunload', ['$event'])
beforeunloadHandler(event) {
  var originalDestroy = this.layout.destroy;
  this.layout.destroy = function() {
      // Call the original
      originalDestroy.apply(this, arguments);
        localStorage.clear();
  };
}

Answer 1

查看the documentation , GoldenLayout 提供了一个 itemDestroyed 事件，您可以 Hook 它来进行自定义清理。描述是:

Fired whenever an item gets destroyed.

如果由于某种原因你不能，一般的答案是你可以很容易地包装函数:

var originalDestroy = this.layout.destroy;
this.layout.destroy = function() {
    // Call the original
    originalDestroy.apply(this, arguments);
    // Do your additional work here
};

如有必要，您可以通过修改 GoldenLayout.prototype 对所有实例执行此操作:

var originalDestroy = GoldenLayout.prototype.destroy;
GoldenLayout.prototype.destroy = function() {
    // Call the original
    originalDestroy.apply(this, arguments);
    // Do your additional work here
};

例子:

// Stand-in for golden laout
function GoldenLayout() {
}
GoldenLayout.prototype.destroy = function() {
    console.log("Standard functionality");
};

// Your override:
var originalDestroy = GoldenLayout.prototype.destroy;
GoldenLayout.prototype.destroy = function() {
    // Call the original
    originalDestroy.apply(this, arguments);
    // Do your additional work here
    console.log("Custom functionality");
};

// Use
var layout = new GoldenLayout();
layout.destroy();