Class ColumnExpression

This is a handle to a column expression. This class is created by the factory methods Create(expression), and can be used to retrieve information about the components of the column expression.

Since

2.0

Hierarchy (View Summary)

Spotfire.Object
- ColumnExpression

Methods

Cast

Cast<T1, T2>(this: T2, type: TypeRef<T1>): T1
Casts this object to the specified type. Throws error on failure.
Type Parameters
- T1
  The target type of the cast.
- T2
  The type of the object to cast.
Parameters
- this: T2
- type: TypeRef<T1>
  The type to cast to.
Returns T1
Inherited from Object.Cast

Equals

Equals(obj: any): boolean
Determines whether the specified object is equal to the current object.
Parameters
- obj: any
  The object to compare with the current object.
Returns boolean
true if the specified object is equal to the current object; otherwise, false.

Inherited from Object.Equals

GetHashCode

GetHashCode(): number
Serves as the default hash function.

Returns number
A hash code for the current object.

Inherited from Object.GetHashCode

ToString

ToString(): string
Returns a string that represents the current object.

Returns string
A string that represents the current object.

Inherited from Object.ToString

TryCast

TryCast<T1, T2>(this: T2, type: TypeRef<T1>): null | T1
Casts this object to the specified type. Returns null on failure.
Type Parameters
- T1
  The target type of the cast.
- T2
  The type of the object to cast.
Parameters
- this: T2
- type: TypeRef<T1>
  The type to cast to.
Returns null | T1
Inherited from Object.TryCast

`Static`Equals

Equals(objA: any, objB: any): boolean
Determines whether the specified object instances are considered equal.
Parameters
- objA: any
  The first object to compare.
- objB: any
  The second object to compare.
Returns boolean
true if the objects are considered equal; otherwise, false. If both objA and objB are null, the method returns true.

Inherited from Object.Equals

Default capability

Alias

get Alias(): string
Get the alias (name) of the calculated column if there is an AS part of the column expression.

Returns string
Since
2.0

ColumnNames

get ColumnNames(): System.Collections.Generic.ICollection<string>
Get the names of all column names referenced in the expression.

Returns System.Collections.Generic.ICollection<string>
Since
2.0

ErrorDisplayMessage

get ErrorDisplayMessage(): string
Get the localized error message if the expression is invalid, null otherwise.

Returns string
Since
2.0

ErrorExpression

get ErrorExpression(): string
Get the expression that could not be parsed if it exists, if the expression is valid then this property is null.

Returns string
Since
2.0

ErrorMessage

get ErrorMessage(): string
Get the error message if the expression is invalid, null otherwise.

Returns string
Since
2.0

Expression

get Expression(): string
Gets the expression as a string. This would exclude any alias (name) statement.

Returns string
Since
2.0

HierarchyNames

get HierarchyNames(): System.Collections.Generic.ICollection<string>
Get all hierarchy names referenced in the expression.

Returns System.Collections.Generic.ICollection<string>
Since
2.0

IsValid

get IsValid(): boolean
True if the expression is valid, false otherwise.

Returns boolean
Since
2.0

MethodNames

get MethodNames(): System.Collections.Generic.ICollection<string>
Get the names of all the methods which are referenced in the expression.

Returns System.Collections.Generic.ICollection<string>
Since
2.0

Clone

Clone(): ColumnExpression
Clone the expression.

Returns ColumnExpression
A clone of the current column expression handle.

Since
2.0

ContainsAggregationMethod

ContainsAggregationMethod(table: DataTable): boolean
Checks if column expression contains an aggregation method.
Parameters
- table: DataTable
  The Spotfire.Dxp.Data.DataTable where the columns and hierarchies referenced in the expression are defined.
Returns boolean
True if the column expression contained an aggregation method, false otherwise.

Since
2.0

GetExpressionReturnType

GetExpressionReturnType(table: DataTable): DataType
Get the result type for the given expression using the columns in the specified table.
Parameters
- table: DataTable
  The Spotfire.Dxp.Data.DataTable where the columns and hierarchies referenced in the expression are defined.
Returns DataType
The return type of the expression.

Since
2.0

QualifyNames

QualifyNames(tableName: string | String): void
Make sure that all column/hierarchy references in the query are fully qualified.
Parameters
- tableName: string | String
  The table name.
Returns void
Since
2.0

RenameColumn

RenameColumn(oldName: string | String, newName: string | String): void
Rename all column references from oldName to newName.
Parameters
- oldName: string | String
  The old column name.
- newName: string | String
  The new column name.
Returns void
Since
2.0

RenameHierarchy

RenameHierarchy(oldName: string | String, newName: string | String): void
Rename all hierarchy references from oldName to newName.
Parameters
- oldName: string | String
  The old hierarchy name.
- newName: string | String
  The new hierarchy name.
Returns void
Since
2.0

Validate

Validate(table: DataTable): boolean
Validates if the column expression is valid in the given Spotfire.Dxp.Data.DataTable context.
Parameters
- table: DataTable
  The Spotfire.Dxp.Data.DataTable where the columns and hierarchies referenced in the expression are defined.
Returns boolean
True if the expression is valid, false otherwise.

Since
2.0

`Static`Create

Create(expression: string | String): ColumnExpression
Parse a column expression and return a ColumnExpression.
Parameters
- expression: string | String
  The column expression.
Returns ColumnExpression
A handle to the parsed column expression. Even if it was not possible to parse the expression a ColumnExpression will still be returned but it will be invalid.

Since
2.0

`Static`CreateFromPlotExpression

CreateFromPlotExpression(
expression: string | String,
dataManager: DataManager,
): System.Collections.Generic.IList<ColumnExpression>
Parse a custom expression that can be used on plots and return a list of ColumnExpressions.
Parameters
- expression: string | String
  The plot expression to parse.
- dataManager: DataManager
  The data manager.
Returns System.Collections.Generic.IList<ColumnExpression>
A list of handles to the parsed expressions if it was not possible to parse the expression an empty list will be returned.

Since
2.0

Class ColumnExpression

Since

Hierarchy (View Summary)

Index

Methods

Default capability

Methods

Cast

Type Parameters

Parameters

Returns T1

Equals

Parameters

Returns boolean

GetHashCode

Returns number

ToString

Returns string

TryCast

Type Parameters

Parameters

Returns null | T1

StaticEquals

Parameters

Returns boolean

Default capability

Alias

Returns string

Since

ColumnNames

Returns System.Collections.Generic.ICollection<string>

Since

ErrorDisplayMessage

Returns string

Since

ErrorExpression

Returns string

Since

ErrorMessage

Returns string

Since

Expression

Returns string

Since

HierarchyNames

Returns System.Collections.Generic.ICollection<string>

Since

IsValid

Returns boolean

Since

MethodNames

Returns System.Collections.Generic.ICollection<string>

Since

Clone

Returns ColumnExpression

Since

ContainsAggregationMethod

Parameters

Returns boolean

Since

GetExpressionReturnType

Parameters

Returns DataType

Since

QualifyNames

Parameters

Returns void

Since

RenameColumn

Parameters

Returns void

Since

RenameHierarchy

Parameters

Returns void

Since

Validate

Parameters

Returns boolean

Since

`Static`Equals

`Static`Create

`Static`CreateFromPlotExpression