在导入的打包库中定义模型类时，在聚合物元素中使用模型的正确方法是什么？
我相信我做对了(基于更多文章，例如How to subscribe to change of an observable field)。
它可以在DARTIUM中使用，但是当它是用JS构建时则不能。我真的无法弄清楚那里发生了什么，请查看日志。侦听器和字段中的值的行为很奇怪。
关键因素:由于某些原因，我的模型类打包在共享库中，必须使用我的输入元素
我想念什么？还是dart2js中有错误？
文件和日志
teSTLib.dart (仅是打包库中的模型，不是聚合物应用程序的一部分):
library testlib;
import 'package:observe/observe.dart';
class MyModel extends Object with Observable{
@observable String foo;
String toString(){
return "MyModel[foo:$foo]";
}
}
在聚合物应用程序中，我们有:
all_elements.dart (使用包导入模型:...)
library test;
import 'package:polymer/polymer.dart';
import 'package:testlib/testlib.dart'; //!!!! note this is important, I need shared model
@CustomTag('my-input')
class MyInput extends PolymerElement {
@published String value;
valueChanged(oldValue){
print('text changed from "$oldValue" to "$value"');
}
MyInput.created() : super.created();
}
@CustomTag('my-form')
class MyForm extends PolymerElement {
@observable MyModel model = new MyModel();
modelChanged(oldValue){
print('text changed from "$oldValue" to "$model"');
}
MyForm.created() : super.created();
void ready(){
model.changes.listen((changes){
print('model properties changed $changes');
});
}
}
和 all_elements.html
<polymer-element name="my-input">
<template>
<p>My Input</p>
<input type="text" value="{{value}}"/>
</template>
</polymer-element>
<polymer-element name="my-form">
<template>
<my-input value="{{model.foo}}"></my-input>
</template>
</polymer-element>
<script type="application/dart" src="all_elements.dart"></script>
和应用程序入口点: testapp.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Test app</title>
<link rel="import" href="all_elements.html">
<script type="application/dart">export 'package:polymer/init.dart';</script>
<script src="packages/browser/dart.js"></script>
</head>
<body>
<my-form></my-form>
</body>
</html>
LOGS :
一切正常，直到将其构建为JS。尝试输入单词“hello”以输入时，我得到:
达腾-好
text changed from "null" to "h"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: null to: h>]
text changed from "h" to "he"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: h to: he>]
text changed from "he" to "hel"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: he to: hel>]
text changed from "hel" to "hell"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: hel to: hell>]
text changed from "hell" to "hello"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: hell to: hello>]
JavaScript-问题(输入“hello”-获取“hel”，输入“mystery”-获取“mytr”)
text changed from "null" to "h"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: null to: h>]
text changed from "h" to "he"
text changed from "he" to "h"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: h to: he>]
text changed from "h" to "hl"
text changed from "hl" to "he"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: he to: hl>]
text changed from "he" to "hel"
text changed from "hel" to "hl"
model properties changed [#<PropertyChangeRecord Symbol("foo") from: hl to: hel>]
text changed from "hl" to "hlo"
text changed from "hlo" to "hel"
最佳答案
当依赖包中有聚合物转换器时，由pub build生成的js与没有差异的js会有很大的不同，特别是涉及检测和传播可观察到的更改的js代码。
尝试将聚合物变压器添加到导入包pubspec中:name: testlib
dependencies:
browser: any
observe: any
polymer: any
transformers:
- polymer:
entry_points:
(请注意，不需要实际的entry_points值，只需存在聚合物变压器条目即可。)
关于dart - 从打包库导入的模型类？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20750107/