奧裏利亞創建包裝SignalBindingBehaviour

Question

一個綁定行爲

我目前得到它使用momentjs到日期轉換爲字符串一個簡單的值轉換器：

export class MomentValueConverter { 
    public toView(value: Date, format: string): string { 
    return moment(value).format(format); 
    } 
} 

然而，無論我用它，我最終不得不將其聯合aurelia-translation-signal，以便在用戶更改當前語言時更新它。

${fileSaved | moment:'ll LTS' & signal:'aurelia-translation-signal'} 

如何，而不是建立一個綁定的行爲會自動處理信令從aurelia-translation-signal？

然後，我可以用它喜歡：

${fileSaved & moment:'ll LTS'} 

Answer 1

有一個在Aurelia大街，國際化庫一個很好的例子，https://github.com/aurelia/i18n/blob/master/src/t.js#L89-L122

import {ValueConverter} from 'aurelia-binding'; 
import {SignalBindingBehavior} from 'aurelia-templating-resources'; 

export class TBindingBehavior { 
    static inject = [SignalBindingBehavior]; 

    constructor(signalBindingBehavior) { 
    this.signalBindingBehavior = signalBindingBehavior; 
    } 

    bind(binding, source) { 
    // bind the signal behavior 
    this.signalBindingBehavior.bind(binding, source, 'aurelia-translation-signal'); 

    // rewrite the expression to use the TValueConverter. 
    // pass through any args to the binding behavior to the TValueConverter 
    let sourceExpression = binding.sourceExpression; 

    // do create the sourceExpression only once 
    if (sourceExpression.rewritten) { 
     return; 
    } 
    sourceExpression.rewritten = true; 

    let expression = sourceExpression.expression; 
    sourceExpression.expression = new ValueConverter(
     expression, 
     't', 
     sourceExpression.args, 
     [expression, ...sourceExpression.args]); 
    } 

    unbind(binding, source) { 
    // unbind the signal behavior 
    this.signalBindingBehavior.unbind(binding, source); 
    } 
} 

UPDATE：信號是按值轉換器已經http://aurelia.io/docs/binding/value-converters#signalable-value-converters

內部支持

import {signalBindings} from 'aurelia-framework'; 

signalBindings('locale-changed'); 


export class FlightTimeValueConverter { 
    signals = ['locale-changed']; 

    toView(date) { 
    return date.toLocaleString(window.currentLocale); 
    } 
}