# Wijmo_Olap.Pivotengine ## Content

PivotEngine Class

Provides a user interface for interactively transforming regular data tables into Olap pivot tables.

Tabulates data in the itemsSource collection according to lists of fields and creates the pivotView collection containing the aggregated data.

Pivot tables group data into one or more dimensions. The dimensions are represented by rows and columns on a grid, and the data is stored in the grid cells.

Type parameters

Heirarchy

Constructors

Properties

Methods

Events

Constructors

constructor

  • Initializes a new instance of the PivotEngine class.

    Parameters

    • Optional options: any

      JavaScript object containing initialization data for the field.

    Returns PivotEngine

Properties

allowFieldEditing

allowFieldEditing: boolean

Gets or sets a value that determines whether users should be allowed to edit the properties of the PivotField objects owned by this PivotEngine.

If you set this property to false, the context menus shown by controls such as the PivotGrid and PivotPanel will not include an option for changing the field settings.

The default value for this property is true.

async

async: boolean

Gets or sets a value that determines whether view updates should be generated asynchronously.

This property is set to true by default, so summaries over large data sets are performed asynchronously to prevent stopping the UI thread.

The default value for this property is true.

autoGenerateFields

autoGenerateFields: boolean

Gets or sets a value that determines whether the engine should generate fields automatically based on the itemsSource.

If you set this property to true, the engine will generate fields for each property of the items in the itemsSource. The PivotField.binding property of the auto-generated fields is set to the property name, and their PivotField.header property is set to a string obtained by capitalizing the first letter of the binding and adding spaces before each capital letter.

For example, a 'customerName' property will cause the engine create a field with PivotField.binding set to 'customerName' and PivotField.header set to 'Customer Name'.

When adding fields to one of the view lists using strings, you must specify the PivotField.header, not the PivotField.binding (unlike bindings, field headers must be unique).

The default value for this property is true.

collectionView

collectionView: ICollectionView<T>

Gets the ICollectionView that contains the raw data.

columnFields

columnFields: PivotFieldCollection

Gets the list of PivotField objects that define the fields shown as columns in the output table.

defaultFilterType

defaultFilterType: FilterType

Gets or sets the default filter type (by value or by condition).

The default value for this property is null, which causes the engine to use FilterType.Both on the client or FilterType.Condition on the server.

exclusiveValueSearch

exclusiveValueSearch: boolean

Gets or sets a value that determines whether the filter should include only values selected by the wijmo.grid.filter.ValueFilter.filterText property.

The default value for this property is true, which matches Excel's behavior.

Set it to false to disable this behavior, so searching only affects which items are displayed on the list and not which items are included in the filter.

fields

fields: PivotFieldCollection

Gets the list of PivotField objects exposed by the data source.

This list is created automatically whenever the itemsSource property is set.

Pivot views are defined by copying fields from this list to the lists that define the view: valueFields, rowFields, columnFields, and filterFields.

For example, the code below assigns a data source to the PivotEngine and then defines a view by adding fields to the rowFields, columnFields, and valueFields lists.

import { PivotEngine } from '@mescius/wijmo.olap';

// create pivot engine
let pe = new PivotEngine();

// set data source (populates fields list)
pe.itemsSource = this.getRawData();

// prevent updates while building Olap view
pe.beginUpdate();

// show countries in rows
pe.rowFields.push('Country');

// show categories and products in columns
pe.columnFields.push('Category');
pe.columnFields.push('Product');

// show total sales in cells
pe.valueFields.push('Sales');

// done defining the view
pe.endUpdate();

filterFields

filterFields: PivotFieldCollection

Gets the list of PivotField objects that define the fields used as filters.

Fields on this list do not appear in the output table, but are still used for filtering the input data.

hasDeferredUpdates

hasDeferredUpdates: boolean

Gets a value that indicates whether the viewDefinition have been changed but the changes have not benn applied yet (deferUpdate mode)

isServer

isServer: boolean

Gets a value that determines whether the engine is bound to a server itemsSource or is using local data.

isUpdating

isUpdating: boolean

Gets a value that indicates whether the engine is currently being updated.

isViewDefined

isViewDefined: boolean

Gets a value that determines whether a pivot view is currently defined.

A pivot view is defined if any of the valueFields, rowFields, or columnFields lists are not empty.

itemsSource

itemsSource: any

Gets or sets the array or ICollectionView that contains the raw data to be analyzed, an object describing an SSAS cube service, or a string containing the URL for a ComponentOne DataEngine service.

The first option (using an array or ICollectionView) is the simplest, but it limits the amount of raw data you can handle. Loading the raw data into an array can take a long time if the data set contains more than about 50,000 items or so.

To use this option, simply set the itemsSource property to any JavaScript array containing the raw data to be analyzed. For example:

import { PivotEngine } from '@mescius/wijmo.olap';
let ng = PivotEngine({
    itemsSource = getDataArray(1000);
});

The second option (direct connection to OLAP SSAS cubes) allows the PivotEngine to connect directly to OLAP cubes provided by SSAS servers. This option removes the size limitations mentioned above and allows you to analyze data sets with millions or billions of records.

To use this option, set the itemsSource property to an object that specifies how the component should access the service. For example:

import { PivotEngine } from '@mescius/wijmo.olap';
let ng = PivotEngine({
    itemsSource: {
        url: 'http://ssrs.componentone.com/OLAP/msmdpump.dll',
        cube: 'Adventure Works',
        catalog: 'AdventureWorksDW2012Multidimensional'
    }
});

The catalog property is optional, but url and cube are required.

The preceding example works with SSAS servers that allow anonymous access. For servers that require Basic Authentication, you should also include the appropriate user and password members as part of the itemsSource object.

When connecting directly to OLAP SSAS cubes, users will not be able to filter fields by value. They will still be able to filter by condition.

The third option, ComponentOne data engine services, allows you to analyze large datasets on a server without downloading the raw data to the client. You can use our high-performance FlexPivot services or interface with Microsoft's SQL Server Analysis Services OLAP Cubes.

To use ComponentOne data engine services, set the itemsSource property to a string containing the URL of the data service. For example:

import { PivotEngine } from '@mescius/wijmo.olap';
let ng = new wijmo.olap.PivotEngine({
    itemsSource: 'http://demos.componentone.com/ASPNET/c1webapi/4.5.20193.222/api/dataengine/cube'
});

The PivotEngine sends view definitions to the server, where summaries are calculated and returned to the client.

When connecting ComponentOne DataEngine data sources, users will not be able to filter fields by value. They will still be able to filter by condition.

For more information about the ComponentOne DataEngine services please refer to the online documentation.

Our OlapServerIntro sample shows all options working with a single PivotEngine.

pivotView

pivotView: ICollectionView<T>

Gets the ICollectionView containing the output pivot view.

rowFields

rowFields: PivotFieldCollection

Gets the list of PivotField objects that define the fields shown as rows in the output table.

serverMaxDetail

serverMaxDetail: number

Gets or sets the maximum number of records the getDetail method should retrieve from the server.

The default value for this property is 1,000, which is a reasonable amount of detail in many scenarios. If you want to allow more detail records to be retrieved, increase the value of this property.

serverPollInterval

serverPollInterval: number

Gets or sets the amount of time, in milliseconds, that the engine should wait before polling the server for progress status while retrieving results.

The default value for this property is 500 milliseconds, which causes the engine to poll the server for a status update every half second.

serverTimeout

serverTimeout: number

Gets or sets the maximum amount of time, in milliseconds, that the engine should wait for the results to come back from the server.

The default value for this property is 60,000 milliseconds, or one minute. If you expect server operations to take longer than that, set the property to a higher value.

showColumnTotals

showColumnTotals: ShowTotals

Gets or sets a value that determines whether the output pivotView should include columns containing subtotals or grand totals.

The default value for this property is ShowTotals.GrandTotals.

showRowTotals

showRowTotals: ShowTotals

Gets or sets a value that determines whether the output pivotView should include rows containing subtotals or grand totals.

The default value for this property is ShowTotals.GrandTotals.

showZeros

showZeros: boolean

Gets or sets a value that determines whether the Olap output table should use zeros to indicate missing values.

The default value for this property is false.

sortOnServer

sortOnServer: boolean

Gets or sets a value that indicates whether the summary data received from the server is already sorted.

If this property is set to true, the PivotEngine will not sort the data it receives from the server.

This property should be used only in conjunction with custom servers that return the aggregated data properly sorted, typically using custom logic not available in the standard PivotEngine.

The default value for this property is false.

sortableGroups

sortableGroups: boolean

Gets or sets a value that determines whether the engine should sort groups when sorting the value fields (measures) or whether it should keep the group order and the data only within each group.

The default value for this property is true.

totalsBeforeData

totalsBeforeData: boolean

Gets or sets a value that determines whether row and column totals should be displayed before or after regular data rows and columns.

If this value is set to true, total rows appear above data rows and total columns appear on the left of regular data columns.

The default value for this property is false.

valueFields

valueFields: PivotFieldCollection

Gets the list of PivotField objects that define the fields summarized in the output table.

viewDefinition

viewDefinition: string

Gets or sets the current pivot view definition as a JSON string.

This property is typically used to persist the current view as an application setting.

For example, the code below implements two functions that save and load view definitions using local storage:

// save/load views
function saveView() {
  localStorage.viewDefinition = pivotEngine.viewDefinition;
}
function loadView() {
  pivotEngine.viewDefinition = localStorage.viewDefinition;
}

Methods

beginUpdate

  • beginUpdate(): void

  • Suspends the refresh processes until next call to the endUpdate.

    Returns void

cancelPendingUpdates

  • cancelPendingUpdates(): void

  • Cancels any pending asynchronous view updates.

    Returns void

deferUpdate

  • deferUpdate(fn: Function): void

  • Executes a function within a beginUpdate/endUpdate block.

    The control will not be updated until the function has been executed. This method ensures endUpdate is called even if the function throws an exception.

    Parameters

    • fn: Function

      Function to be executed.

    Returns void

editField

  • Shows a settings dialog where users can edit a field's settings.

    Parameters

    Returns void

endUpdate

  • endUpdate(): void

  • Resumes refresh processes suspended by calls to beginUpdate.

    Returns void

getDetail

  • getDetail(item: any, binding: string): any[]

  • Gets an array containing the records summarized by a property in the pivotView list.

    If the engine is connected to a PivotEngine server, the value returned is an ObservableArray that is populated asynchronously.

    Parameters

    • item: any

      Data item in the pivotView list.

    • binding: string

      Name of the property being summarized.

    Returns any[]

getDetailView

  • Gets an {@link collections.ICollectionView} containing the records summarized by a property in the pivotView list.

    Parameters

    • item: any

      Data item in the pivotView list.

    • binding: string

      Name of the property being summarized.

    Returns ICollectionView<T>

getKeys

  • getKeys(item: any, binding: string): any

  • Gets an object with information about a property in the pivotView list.

    The object returned has two properties, 'rowKey' and 'colKey'. Each of these contains two arrays, 'fields' and 'values'. Together, this information uniquely identifies a value summarized by the PivotEngine.

    For example, calling getKeys against a pivot view with two row fields 'Product' and 'Country', and a single column field 'Active' would return an object such as this one:

    {
    rowKey: {
        fields: [ 'Product', 'Country'],
        values: [ 'Aoba', 'Japan' ]
    },
    colKey: {
        fields: [ 'Active' ],
        values: [ true ]
    }
}

    The object identifies the subset of data used to obtain one summary value. In this case, this value represents all data items for product 'Aoba' sold in Japan with Active state set to true.

    Parameters

    • item: any

      Data item in the pivotView list.

    • binding: string

      Name of the property being summarized.

    Returns any

invalidate

  • invalidate(): void

  • Invalidates the view causing an asynchronous refresh.

    Returns void

onError

onItemsSourceChanged

onUpdatedView

onUpdatingView

onViewDefinitionChanged

  • onViewDefinitionChanged(e?: EventArgs): void

refresh

  • refresh(force?: boolean): void

  • Summarizes the data and updates the output pivotView.

    Parameters

    • Optional force: boolean

      Refresh even while updating (see beginUpdate).

    Returns void

removeField

  • Removes a field from the current view.

    Parameters

    Returns void

Events

error

error: Event<PivotEngine<any>, RequestErrorEventArgs>

Occurs when there is an error getting data from the server.

itemsSourceChanged

itemsSourceChanged: Event<PivotEngine<any>, EventArgs>

Occurs after the value of the itemsSource property changes.

updatedView

updatedView: Event<PivotEngine<any>, EventArgs>

Occurs after the engine has finished updating the pivotView list.

updatingView

updatingView: Event<PivotEngine<any>, ProgressEventArgs>

Occurs when the engine starts updating the pivotView list.

viewDefinitionChanged

viewDefinitionChanged: Event<PivotEngine<any>, EventArgs>

Occurs after the view definition changes.