Data Loading Modes
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Data loading in the ExpressQuantumGrid control is implemented via a data controller. A data controller is a core module that connects a grid View to a data store and implements data-related operations (grouping, filtering, sorting, summary calculations, etc.) Each grid View has a DataController property that provides access to a data controller.
There are four main data loading modes provided by data controllers:
Bound mode. A data controller is connected to a TDataSet using a TDataSource object.
Server mode. A data controller is connected to a database via a specially designed data source component (TdxServerModeFireDACDataSource, TdxServerModeDBXDataSource, TdxServerModeADODataSource, TdxServerModeFireDACQueryDataSource, TdxServerModeDBXQueryDataSource, or TdxServerModeADOQueryDataSource) linked to a FireDAC, dbExpress, or ADO connection (TFDConnection/TADConnection, TSQLConnection, or TADOConnection), correspondingly.
Provider mode. A data controller is connected to a user-defined (custom) data source and data is requested as needed.
Unbound mode. A data controller is not connected to a data source and is pre-populated with records manually.
Grid Views can be divided into two main groups: data-aware Views and non data-aware Views. Data-aware Views include either DB or ServerMode in the class name. All other Views are non data-aware Views.
Data-Aware View Specifics
DB Views access data in bound mode using a TcxDBDataController object or one of its descendants as a data-aware data controller.
DB Views include:
ServerMode Views access data in server mode using a TcxGridServerModeDataController object as a data-aware data controller.
ServerMode Views include:
Refer to the following topic for information on how to bind data-aware Views to data in these modes: Connecting to Data in Server Mode.
Non Data-Aware View Specifics
Non data-aware Views (TcxGridTableView, TcxGridBandedTableView, TcxGridCardView, TcxGridChartView, and TcxGridLayoutView) are designed to work in provider and unbound modes.
In provider mode, data is retrieved from a user-defined data source. This mode can be used, for instance, when you need to display structured data within your grid control. The TcxCustomDataSource class provides an interface, which must be overridden to implement a data source with which your data controller can work. Typically, creating a custom data source requires code in only two methods. See the Provider Mode topic to learn more.
In unbound mode, the data controller must be populated manually. First, you should set the number of records in your data controller and set item values for each record. The Unbound Mode section provides more information on the implementation of unbound mode.
Non Data-Aware Views include: