js中解析attachment(非attachmentSimple)相关附件组件存储的json

如果要从附件组件存储的json中获取docID、fileID等信息，需要对json传进行解析
js中参考如下：

		var data = this.comp("mainData");
		var fFJ = data.getValue("fFJ");
		var jsonList = eval("(" + fFJ + ")");
		if (jsonList.length > 0) {
			for (var i = 0; i < jsonList.length; i++) {
				var docID = jsonList[i]["docID"];
				var fileID = jsonList[i]["fileID"];
			}
		}