如何向 Handlebars.net 注册 JavaScript 助手

How to register JavaScript helpers with Handlebars.net

我们如何在 Handlebars.Net 中注册这两个 JavaScript 助手?

对于Moment.js:

Handlebars.registerHelper("formatDate", function (datetime, format) {
    return moment(datetime).format(format);
});

对于java脚本计算:

Handlebars.registerHelper("formatPercent", function (val1, limit) {
    return Math.ceil(100 * val1 / limit);
});m

找到了。这个例子说明了一些问题 https://gist.github.com/rexm/e1a045b9f76a48de642e

    Handlebars.RegisterHelper("formatDate", New HandlebarsHelper(Sub(w, c, p)
                                                                     w.WriteSafeString("moment(" + p(0) + ").format(" + p(1) + ");")
                                                                 End Sub))

    Handlebars.RegisterHelper("formatPercent", New HandlebarsHelper(Sub(w, c, p)
                                                                        If p(1) = 0 Then
                                                                            w.WriteSafeString("0")
                                                                        Else
                                                                            w.WriteSafeString("Math.ceil(" + 100 * p(0) / p(1) + ");")
                                                                        End If
                                                                    End Sub))

readme给出了一个如何编写helpers的例子:

Handlebars.RegisterHelper("link_to", (writer, context, parameters) => {
  writer.WriteSafeString("<a href='" + context.url + "'>" + context.text + "</a>");
});

string source = @"Click here: {{link_to}}";

var template = Handlebars.Compile(source);

var data = new {
    url = "https://github.com/rexm/handlebars.net",
    text = "Handlebars.Net"
};

var result = template(data);

/* Would render:
Click here: <a href='https://github.com/rexm/handlebars.net'>Handlebars.Net</a>
*/

最重要的区别是在 .NET 中,助手没有 return 值。相反,您得到了对生成模板输出的 TextWriter 的引用。因此,您的助手可以通过该编写器将任何它想要的内容直接写入模板。包含一个 .WriteSafeString() 帮助程序来绕过默认编码。 确保您的字符串实际上是安全的,在您这样做时不进行编码。