IsNullOrEmpty(string) 和 List.Count > 0 in mustache-sharp

Question

我使用mustache-sharp作为模板引擎

我想知道到底有没有用这个模板引擎，有两个条件可以检查

1) IsNullOrEmpty(string)  => e.g. {{#IsNullOrEmpty MyName}}} {{/IsNullOrEmpty}}
2) List.Count > 0         => e.g. {{#Any Persons}} {{/Any}}

任何人都可以指导我如何创建如上所述的标签？

Answer 1

您可以尝试创建自定义 ContentTagDefinition 并在 HtmlFormatCompiler.

中注册它

例如：

IsNullOrEmpty

public class IsNullOrEmptyTagDefinition : ContentTagDefinition
{
    private const string conditionParameter = "condition";

    public IsNullOrEmptyTagDefinition()
        : base("IsNullOrEmpty")
    {}

    public override IEnumerable<TagParameter> GetChildContextParameters()
    {
        return new TagParameter[0];
    }

    public override bool ShouldGeneratePrimaryGroup(Dictionary<string, object> arguments)
    {
        object condition = arguments[conditionParameter];
        return isConditionSatisfied(condition);
    }

    protected override IEnumerable<TagParameter> GetParameters()
    {
        return new TagParameter[] { new TagParameter(conditionParameter) { IsRequired = true } };
    }

    protected override bool GetIsContextSensitive()
    {
        return false;
    }

    private bool isConditionSatisfied(object condition)
    {
        if (condition == null)
        {
            return true;
        }

        return condition is string ? string.IsNullOrEmpty(condition as string) : false;
    }

}

任意

public class AnyTagDefinition : ContentTagDefinition
{
    private const string conditionParameter = "condition";

    public AnyTagDefinition()
        : base("Any")
    {}

    public override IEnumerable<TagParameter> GetChildContextParameters()
    {
        return new TagParameter[0];
    }

    public override bool ShouldGeneratePrimaryGroup(Dictionary<string, object> arguments)
    {
        object condition = arguments[conditionParameter];
        return isConditionSatisfied(condition);
    }

    protected override IEnumerable<TagParameter> GetParameters()
    {
        return new TagParameter[] { new TagParameter(conditionParameter) { IsRequired = true } };
    }

    protected override bool GetIsContextSensitive()
    {
        return false;
    }

    private bool isConditionSatisfied(object condition)
    {
        if (condition is IEnumerable)
        {
            return (condition as IEnumerable).Cast<object>().Any();
        }

        return false;
    }

}

注册两个标签

HtmlFormatCompiler compiler = new HtmlFormatCompiler();
compiler.RegisterTag(new IsNullOrEmptyTagDefinition(), true);
compiler.RegisterTag(new AnyTagDefinition(), true);

IsNullOrEmpty(string) 和 List.Count > 0 in mustache-sharp

IsNullOrEmpty(string) and List.Count > 0 in mustache-sharp

c#

template-engine

mustache