我将 Handlebars .NET 用于我的邮件模板，因此我在服务器端宽度 ASP.NET MVC 处生成模板。我需要这样的比较。但它不起作用？我能做些什么？
//Product.ProdType is a enum property
{{#if (Product.ProdType=='BlaBlaBla')}}
<p>This is a test</p>
{{/if}}
问问题
10407 次
4 回答
8
我遇到了同样的问题，我创建了一个适用于数字数据类型和字符串的辅助函数“ifCond”。它可以被优化或扩展以与其他类型一起使用。
Handlebars.RegisterHelper("ifCond",
(writer, context, args) =>
{
if (args.Length != 5)
{
writer.Write("ifCond:Wrong number of arguments");
return;
}
if (args[0] == null || args[0].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[0] undefined");
return;
}
if (args[1] == null || args[1].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[1] undefined");
return;
}
if (args[2] == null || args[2].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[2] undefined");
return;
}
if (args[0].GetType().Name == "String")
{
string val1 = args[0].ToString();
string val2 = args[2].ToString();
switch (args[1].ToString())
{
case ">":
writer.Write(val1.Length > val2.Length ? args[3] : args[4]);
break;
case "=":
case "==":
writer.Write(val1 == val2 ? args[3] : args[4]);
break;
case "<":
writer.Write(val1.Length < val2.Length ? args[3] : args[4]);
break;
case "!=":
case "<>":
writer.Write(val1 != val2 ? args[3] : args[4]);
break;
}
}
else
{
float val1 = float.Parse(args[0].ToString());
float val2 = float.Parse(args[2].ToString());
switch (args[1].ToString())
{
case ">":
writer.Write(val1 > val2 ? args[3] : args[4]);
break;
case "=":
case "==":
writer.Write(val1 == val2 ? args[3] : args[4]);
break;
case "<":
writer.Write(val1 < val2 ? args[3] : args[4]);
break;
case "<=":
writer.Write(val1 <= val2 ? args[3] : args[4]);
break;
case ">=":
writer.Write(val1 >= val2 ? args[3] : args[4]);
break;
case "!=":
case "<>":
writer.Write(val1 != val2 ? args[3] : args[4]);
break;
}
}
以下是一些解释用法的单元测试：
var template = Handlebars.Compile("{{{ifCond test '>' 1 '>1' '<=1' }}}");
var data = new { test = 2 };
var result = template(data);
Assert.AreEqual(">1", result);
data = new { test = 0 };
result = template(data);
Assert.AreEqual("<=1", result);
template = Handlebars.Compile("{{{ifCond test '=' 1 'eq' 'not eq' }}}");
data = new { test = 1 };
result = template(data);
Assert.AreEqual("eq", result);
data = new { test = 0 };
result = template(data);
Assert.AreEqual("not eq", result);
template = Handlebars.Compile("{{{ifCond test '!=' 1 'diff' 'eq' }}}");
data = new { test = 2 };
result = template(data);
Assert.AreEqual("diff", result);
template = Handlebars.Compile("{{{ifCond str '!=' '' 'not empty' 'empty' }}}");
var datastr = new { str = "abc" };
result = template(datastr);
Assert.AreEqual("not empty", result);
template = Handlebars.Compile("{{{ifCond str '==' '' 'empty' 'not empty' }}}");
datastr = new { str = "" };
result = template(datastr);
Assert.AreEqual("empty", result);
希望它有所帮助，我也希望有一个更好的实现，更优雅，我的解决方案有效，但我认为它可以以更简洁的方式完成。
这是一个在模板中使用 Int32 值的用法示例：
{{ifCond MycountVariable '>' 1 'more than one' 'one'}}
这是一个在模板中带有字符串值的用法示例：
{{ifCond MyStringVariable '!=' '' MyStringVariable 'empty value'}}
于 2016-04-06T12:37:55.460 回答
3
我正在使用 Handlebars.NET 作者在其单元测试中提交的方式，它就像一个魅力：
Handlebars.RegisterHelper("ifCond", (writer, options, context, arguments) =>
{
if (arguments[0] == arguments[1])
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
});
（至少在 Handlebars.NET 1.10.1 中）。
于 2019-03-29T08:31:23.993 回答
1
像您尝试做的逻辑必须在辅助函数中。您不能将这样的关系运算符直接放入车把模板中。它是故意这样设计的。助手很容易创建和使用。请参阅http://handlebarsjs.com/#helpers更多信息。
hbs.registerHelper("IsSame", function(ProdType) {
if(ProdType == "BlaBlaBla") {
$('#HereText').append('<p>This is a test</p>');
}
});
在模板中执行此操作
<div class="row">
{{IsSame Product.ProdType}}
</div>
所以在这里你将你的值传递给一个辅助函数并进行比较..
于 2015-06-19T09:09:36.603 回答
0
我尝试了@Matteo Conta 的解决方案，但它不支持变量与文本结合。所以我对其进行了一些调整，以便更容易使用和更好地支持变量。
句法
{{#ifCond arg1 condition arg2}}
True clause {{variable}}
{{else}}
False clause {{variable}}
{{/ifCond}}
代码
Handlebars.RegisterHelper("ifCond", (writer, options, context, args) => {
if (args.Length != 3)
{
writer.Write("ifCond:Wrong number of arguments");
return;
}
if (args[0] == null || args[0].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[0] undefined");
return;
}
if (args[1] == null || args[1].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[1] undefined");
return;
}
if (args[2] == null || args[2].GetType().Name == "UndefinedBindingResult")
{
writer.Write("ifCond:args[2] undefined");
return;
}
if (args[0].GetType().Name == "String")
{
var val1 = args[0].ToString();
var val2 = args[2].ToString();
switch (args[1].ToString())
{
case ">":
if (val1.Length > val2.Length)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "=":
case "==":
if (val1 == val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "<":
if (val1.Length < val2.Length)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "!=":
case "<>":
if (val1 != val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
}
}
else
{
var val1 = float.Parse(args[0].ToString());
var val2 = float.Parse(args[2].ToString());
switch (args[1].ToString())
{
case ">":
if (val1 > val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "=":
case "==":
if (val1 == val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "<":
if (val1 < val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
case "!=":
case "<>":
if (val1 != val2)
{
options.Template(writer, (object)context);
}
else
{
options.Inverse(writer, (object)context);
}
break;
}
}
});
示例用法
var template = Handlebars.Compile(@"{{#ifCond arg1 '>' arg2}}{{arg1}} is greater than {{arg2}}{{else}}{{arg1}} is less than {{arg2}}{{/ifCond}}");
var data = new { arg1 = 2 , arg2 = 1};
var result = template(data);
Assert.Equal("2 is greater than 1", result);
data = new { arg1 = 1, arg2 = 2 };
result = template(data);
Assert.Equal("1 is less than 2", result);
template = Handlebars.Compile(@"{{#ifCond arg1 '<' arg2}}{{arg1}} is less than {{arg2}}{{else}}{{arg1}} is greater than {{arg2}}{{/ifCond}}");
data = new { arg1 = 2, arg2 = 1 };
result = template(data);
Assert.Equal("2 is greater than 1", result);
data = new { arg1 = 1, arg2 = 2 };
result = template(data);
Assert.Equal("1 is less than 2", result);
template = Handlebars.Compile(@"{{#ifCond arg1 '=' arg2}}{{arg1}} is eq to {{arg2}}{{else}}{{arg1}} is not eq to {{arg2}}{{/ifCond}}");
data = new { arg1 = 1, arg2 = 1 };
result = template(data);
Assert.Equal("1 is eq to 1", result);
data = new { arg1 = 2, arg2 = 1 };
result = template(data);
Assert.Equal("2 is not eq to 1", result);
template = Handlebars.Compile(@"{{#ifCond arg1 '!=' arg2}}{{arg1}} is not eq to {{arg2}}{{else}}{{arg1}} is eq to {{arg2}}{{/ifCond}}");
data = new { arg1 = 2, arg2 = 1 };
result = template(data);
Assert.Equal("2 is not eq to 1", result);
template = Handlebars.Compile(@"{{#ifCond str '!=' ''}}not empty{{else}}empty{{/ifCond}}");
var datastr = new { str = "abc" };
result = template(datastr);
Assert.Equal("not empty", result);
template = Handlebars.Compile(@"{{#ifCond str '==' ''}}empty{{else}}not empty{{/ifCond}}");
datastr = new { str = "" };
result = template(datastr);
Assert.Equal("empty", result);
于 2017-11-06T10:05:27.290 回答