Javascript 教程:基于L20n库的node.js/Polymer i18n解决方案
在Javascript 教程:基于L20n库的node.js/Polymer i18n解决方案,javascript,node.js,internationalization,polymer,l20n,Javascript,Node.js,Internationalization,Polymer,L20n,在node.jsweb项目中实现i18n有一个相当常见的问题。如果您想: 使用web组件(例如) 对服务器端和客户端文件使用单个翻译文件 按程序翻译某些项目(如动态创建的字符串) 由于Mozilla团队开发了全新的解决方案,这个问题可以很容易地解决。项目结构 首先,我创建了一个项目结构,它将按照文件的用途将文件分开存放: . +-- app.js +-- piblic | +-- locales | +-- app.ru.l20n | +-- app.en.l20n
node.js
web项目中实现i18n有一个相当常见的问题。如果您想:
.
+-- app.js
+-- piblic
| +-- locales
| +-- app.ru.l20n
| +-- app.en.l20n
|
+-- node_models
| +-- l20n
|
+-- bower_components
| +-- Polymer libraries
|
+-- app_modules
| +-- app-l20n-node
| +-- index.js
|
+-- app_components
+-- app-l20n
+-- app-l20n.html
+-- app-custom-component
+-- app-custom-component.html
想法很简单:app-l20n-node
被用作所有服务器端作业的本地化模块,app-l20n
是用于用户界面l10n的聚合物组件
装置
运行npm安装l20n——保存
当前版本是3.5.1,它有一个小错误。l20n的主文件是/dist/compat/node/l20n.js
,它有两个必需的变量,这些变量在代码中的任何地方都没有使用,但在启动时会压碎你的应用程序,因为它们只在库的devdependences中提到。为了避免这种情况,我只是将它们直接注释到库代码中:
//var string_prototype_startswith = require('string.prototype.startswith');
//var string_prototype_endswith = require('string.prototype.endswith');
翻译文件
我在我的/public/locales/
文件夹中创建了翻译文件,名为app.ru.l20n
和app.en.l20n
。根据L20n规则,文件的内容如下所示:
<foo "Foo translation">
<bar "Bar translation">
<register[$variant] {
infinitive: "Register now!"
}>
现在,我们可以在node.js代码中使用这个模块,并根据键和区域设置请求获得翻译。我使用express sessions
代替硬编码的区域设置,并将用户定义的区域设置存储为session属性req.session.locale
。但这一切都取决于项目
var l20n = require('../../app_modules/app-l20n-node');
l20n(['foo','bar'], 'en')
.then((t)=>{
console.log(t); // ["Foo translation", "Bar translation"]
});
聚合物+L20n
现在我们应该为L20n创建一个聚合物组分。首先,将库和翻译文件链接添加到html
:
不,因为新的行为已经准备好了,我们可以在我们的定制聚合物组件中实现它。您可以通过聚合行为或使用L20n自定义标记属性功能以编程方式获得转换
<link rel="import" href="/bower_components/polymer/polymer.html">
<link rel="import" href="/bower_components/gold-email-input/gold-email-input.html">
<link rel="import" href="/bower_components/paper-button/paper-button.html">
<link rel="import" href="/app_components/app-l20n/app-l20n.html">
<dom-module id="app-custom-component">
<template>
<gold-email-input
auto-validate
required
name="email"
value="{{Foo}}"
label="{{Bar}}">
</gold-email-input>
<paper-button onclick="regFormSubmit(event)">
<iron-icon icon="perm-identity"></iron-icon>
<span data-l10n-id="Register" data-l10n-args='{"variant": "infinitive"}'></span>
</paper-button>
</template>
<script>
function regFormSubmit(event){}
Polymer({
is: 'app-custom-component',
behaviors: [
MB.i18n
],
ready: function(){
this.$.passwordValidator.validate = this._validatePasswords.bind(this);
// add your component properties to array. They can be simple like in this example, or
// more complex, with parameters: ["Some_key", {param: "xxx"}].
// you can even translate the same string in different properties, using custom suffix:
// ["Some_key", {param: "yyy"}, "_suffix"] and place it in template with shortcut: {{Some_key_suffix}}
var translateProps = ["Foo", "Bar"];
// now translate, using behavior
this.translate(this, translateProps);
}
});
</script>
</dom-module>
函数regFormSubmit(事件){}
聚合物({
是:“应用程序自定义组件”,
行为:[
MB.i18n
],
就绪:函数(){
this.$.passwordValidator.validate=this.\u validatePasswords.bind(this);
//将组件属性添加到数组中。它们可以像本例中那样简单,也可以
//更复杂,参数:[“Some_key”,{param:“xxx”}]。
//您甚至可以使用自定义后缀转换不同属性中的相同字符串:
//[“Some_key”、{param:“yyy”}、“\u suffix”]并使用快捷方式将其放置在模板中:{Some_key_suffix}
var translateProps=[“Foo”,“Bar”];
//现在,使用行为进行翻译
这个,翻译(这个,翻译操作);
}
});
希望这个小教程会有帮助
<script src="/node_modules/l20n/dist/compat/web/l20n.js"></script>
<link rel="localization" href="/locales/app.{locale}.l20n">
<script>
/**
* Create namespace for custom behavior or use existing one.
*/
window.MB = window.MB || {};
MB.i18n = {
/**
* Use l20n.js to translate certain strings
* @param component A Polymer component, usually "this.translate(this, props);"
* @param props An array of keys to translate: strings or arrays.
*/
translate: function(component, props) {
var view = document.l10n;
var promise = view.formatValues.apply(view, props);
promise.then(function(args){
for (var i in args){
var prop = props[i];
// strings with parameters represented by arrays:
// ["string", {param: value}]
if (Array.isArray(prop)) {
// get property name - usually the same, as translation key
// so the object would have properties obj.Foo and obj.Bar
var propName = prop[0];
// if it is needed to create multiple translations of the same
// string in one component, but with different parameters,
// the best way is to use suffix:
// ["string", {param: value}, "_suffix"]
if (prop.length == 3) propName = propName + prop[2];
component.set(propName, args[i]);
}
// common strings
else component.set(prop, args[i]);
}
});
}
};
</script>
<link rel="import" href="/bower_components/polymer/polymer.html">
<link rel="import" href="/bower_components/gold-email-input/gold-email-input.html">
<link rel="import" href="/bower_components/paper-button/paper-button.html">
<link rel="import" href="/app_components/app-l20n/app-l20n.html">
<dom-module id="app-custom-component">
<template>
<gold-email-input
auto-validate
required
name="email"
value="{{Foo}}"
label="{{Bar}}">
</gold-email-input>
<paper-button onclick="regFormSubmit(event)">
<iron-icon icon="perm-identity"></iron-icon>
<span data-l10n-id="Register" data-l10n-args='{"variant": "infinitive"}'></span>
</paper-button>
</template>
<script>
function regFormSubmit(event){}
Polymer({
is: 'app-custom-component',
behaviors: [
MB.i18n
],
ready: function(){
this.$.passwordValidator.validate = this._validatePasswords.bind(this);
// add your component properties to array. They can be simple like in this example, or
// more complex, with parameters: ["Some_key", {param: "xxx"}].
// you can even translate the same string in different properties, using custom suffix:
// ["Some_key", {param: "yyy"}, "_suffix"] and place it in template with shortcut: {{Some_key_suffix}}
var translateProps = ["Foo", "Bar"];
// now translate, using behavior
this.translate(this, translateProps);
}
});
</script>
</dom-module>