/// <summary> /// 变量表达式 /// </summary> /// <param name="variableId"></param> /// <param name="fieldName"></param> /// <param name="isMethod"></param> /// <param name="needCacheData"></param> internal VariableExpression(VariableIdentity variableId, string fieldName, bool isMethod, bool needCacheData) { this.VariableId = variableId; this.FieldName = fieldName; this.IsMethod = isMethod; this.NeedCacheData = needCacheData; }
/// <summary> /// 添加标签属性时的触发函数.用于设置自身的某些属性值 /// </summary> /// <param name="name"></param> /// <param name="item"></param> public override void OnAddingAttribute(string name, Attribute item) { switch (name) { case "index": this.Index = ParserHelper.CreateVariableIdentity(this.OwnerTemplate, item.Text); break; } }
/// <summary> /// 克隆表达式 /// </summary> /// <param name="ownerTemplate"></param> /// <returns></returns> public IExpression Clone(Template ownerTemplate) { VariableIdentity variableId = this.VariableId.Clone(ownerTemplate); VariableExpression exp = new VariableExpression(variableId, this.FieldName, this.IsMethod, this.NeedCacheData); if (this.NextExpression != null) { exp.NextExpression = (VariableExpression)(this.NextExpression.Clone(ownerTemplate)); exp.NextExpression.ParentExpression = exp; } return(exp); }
/// <summary> /// 构建变量标签元素 /// </summary> /// <param name="ownerTemplate">宿主模板</param> /// <param name="container">标签的容器</param> /// <param name="match"></param> internal static VariableTag CreateVariableTag(Template ownerTemplate, Tag container, Match match) { string prefix; Variable variable = CreateVariable(ownerTemplate, match, out prefix); VariableIdentity variableId = new VariableIdentity(ownerTemplate, variable, prefix); //变量标签元素则需要缓存表达式的值 VariableExpression varExp = CreateVariableExpression(variableId, match, true); VariableTag tag = new VariableTag(ownerTemplate, varExp); //解析属性列表 ParseElementAttributes(tag, match); container.AppendChild(tag); return tag; }
/// <summary> /// 构建变量的字段列表 /// </summary> /// <param name="variableId"></param> /// <param name="match"></param> /// <param name="needCacheData"></param> /// <returns></returns> internal static VariableExpression CreateVariableExpression(VariableIdentity variableId, Match match, bool needCacheData) { //解析变量字段列表 VariableExpression field = new VariableExpression(variableId, needCacheData); CaptureCollection fields = match.Groups["field"].Captures; CaptureCollection methods = match.Groups["method"].Captures; VariableExpression item = field; for (var i = 0; i < fields.Count; i++) { string fieldName = fields[i].Value; VariableExpression exp = new VariableExpression(item, fieldName, !string.IsNullOrEmpty(methods[i].Value)); item = exp; } return field; }
/// <summary> /// 呈现本元素的数据 /// </summary> /// <param name="writer"></param> protected override void RenderTagData(System.IO.TextWriter writer) { decimal from = Utility.ConverToDecimal(this.From.Value.GetValue()); decimal step = this.Step == null ? 1 : Utility.ConverToDecimal(this.Step.Value.GetValue()); decimal to = Utility.ConverToDecimal(this.To.Value.GetValue()); decimal index = from; LoopIndex li = new LoopIndex(index); if (this.Index != null) { this.Index.Value = li; } if (step >= 0) { while (index <= to) { li.Value = index; li.IsFirst = (index == from); li.IsLast = (index == to); if (this.Index != null) { this.Index.Variable.Reset(); } base.RenderTagData(writer); index += step; } } else { while (index >= to) { li.Value = index; li.IsFirst = (index == from); li.IsLast = (index == to); if (this.Index != null) { this.Index.Variable.Reset(); } base.RenderTagData(writer); index += step; } } }
/// <summary> /// 从变量表达式文本(如:name.age)中构建变量表达式 /// </summary> /// <param name="ownerTemplate"></param> /// <param name="expressionText"></param> /// <param name="needCacheData"></param> /// <returns></returns> internal static VariableExpression CreateVariableExpression(Template ownerTemplate, string expressionText, bool needCacheData) { if (string.IsNullOrEmpty(expressionText)) return null; Match match = ParserRegex.VarExpRegex.Match(expressionText); if (match.Success) { string prefix; Variable variable = CreateVariable(ownerTemplate, match, out prefix); VariableIdentity variableId = new VariableIdentity(ownerTemplate, variable, prefix); return CreateVariableExpression(variableId, match, needCacheData); } else { //非变量表达式 throw new ParserException(string.Format("变量表达式\"{0}\"的定义格式错误", expressionText)); } }
/// <summary> /// 变量表达式 /// </summary> /// <param name="variableId"></param> /// <param name="needCacheData"></param> public VariableExpression(VariableIdentity variableId, bool needCacheData) : this(variableId, null, false, needCacheData) { }