IsNullOrEmpty（串）和List.Count> 0小鬍子銳

Question

我用mustache-sharp作爲模板引擎

我想知道反正是有使用這個模板引擎，並有檢查

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

兩個條件

任何人都可以引導我如何創建上面的標籤？

Answer 1

您可以嘗試創建一個自定義ContentTagDefinition和HtmlFormatCompiler註冊。

例如：

1. 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; 
       } 
   
   } 
   

2. 任何

   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; 
       } 
   
   } 
   

3. 註冊兩個標籤

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