EqExpression class

Represents common expression object.

public abstract class Korzh.EasyQuery.EqExpression

Package: Korzh.EasyQuery (targets: netstandard2.0)

Assembly: Korzh.EasyQuery.dll

Constructors

Name	Type	Description
EqExpression(DataModel model)	void	Initializes a new instance of the Korzh.EasyQuery.EqExpression class.

Fields

Name	Type	Description
_text	string	This field contains expression’s text

Properties

Name	Type	Description
Attribute	EntityAttr	Gets or sets the attribute.
CustomFunc	string	Gets the custom func for expression if defined
DataType	DataType	Gets or sets the data type.
Hint	string	Gets or sets the expression hint.
IsAggregate	bool	Gets a value indicating whether this expression is aggregate.
Kind	DataKind	Gets the expression kind.
Model	DataModel	Gets the model.
SystemType	Type	Gets the system type for this expreesion (it’s used in LINQ query builder)
Tag	int	Get the expression’s tag - a special identifier that is used to distinguish the type of the expression .
Text	string	Gets or sets the expression text used for visual representation.
Value	string	Gets or sets the value of expression.

Events

Name	Type	Description
ContentChange	EventHandler	This event is raised after expression was changed

Methods

Name	Type	Description
AssignExpr(EqExpression expr)	void	Assigns some expression to this one. This method just does nothing in the base class but can perform some actions in Expression descendants.
Clone()	EqExpression
CloneAsync()	Task<EqExpression>
ContentChanged()	void	Invoke ContentChange event
LoadFromXmlReader(XmlReader reader)	void	Loads expression from XML.
OnContentChange(EventArgs e)	void	Raises the ContentChange event.
ReadOnePropFromJsonAsync(JsonReader reader, string propName)	Task	Reads one expression property from JSON (asynchronous way).
SaveToJsonStringAsync()	Task<string>
SaveToXmlWriter(XmlWriter writer, string xmlTagName)	void	Saves expression to XML writer.
SaveToXmlWriter(XmlWriter writer)	void	Saves expression to XML writer.
SetContent(string val, string txt)	void	Sets the content of the expression (both its value and text).
SetContentSilent(string val, string txt)	void	Sets the content of the expression silently (without calling ContentChanged event).
TagToOldClassName(int tag)	string	Converts the expression’s tag value to the name of old expression class (like “CONST” or “ENTATTR”).
WritePropertiesToJsonAsync(JsonWriter writer)	Task	Writes all experssion properties to JSON (asynchronous way). This method must be overriden in the descendant classes
WriteToJsonAsync(JsonWriter writer)	Task	Write the content of the expression to JSON (asynchronous way).
WriteXmlTagStart(XmlWriter writer)	void	Writes the expression XML tag start.
WriteXmlTagStart(XmlWriter writer, string tagName)	void	Writes the expression XML tag start.

Static Properties

Name	Type	Description
XmlTagName	string	Gets the name of the XML tag used for representation of Expression (an all its descendants) object in XML files.

Static Methods

Name	Type	Description
Create(DataModel model, int tag)	EqExpression	Creates the expression instance of specified type.
CreateByClassName(DataModel model, string className)	EqExpression	Creates the expression instance of specified class (type) name.
ReadFromJsonAsync(DataModel model, JsonReader reader)	Task<EqExpression>	Reads one expression from JSON.(asynchronous way). This static function recognizes the expression type and creates an instance of appropriate class.
RegisterCreator(IExpressionCreator creator)	bool	Registers new type of expression.