# Global Objects Overview Telerik script language provides the following intrinsic (or "built-in") objects that may be used in [report expressions](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/expressions/overview) inside the report definition. ## Fields The `Fields` collection represents the set of fields specified by the report data source plus any additional calculated fields that you create. It is a **function** that requires a string argument with the name of the data field and not an **object** like `ReportItem.DataObject`. After you create a data source for a [report data item](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/data-items/overview) (Report, Table, Crosstab, List, Chart), the field collection appears in the [Data Explorer tool](https://www.telerik.com/products/reporting/documentation/designing-reports/report-designer-tools/desktop-designers/tools/data-explorer). Example: `Fields.ProductID` - returns the value of the field ProductID in the current data scope instance. If the data source does not contain the referenced column, an error is thrown. If the report has no data source set, the expression result is null (Nothing) > note If the data source field name is not a valid name in terms of programming languages (contains spaces, punctuation marks, etc.) enclose its name in square brackets, for example =Fields.\[My Column]; Because brackets are special characters, you must use a backslash (`\\`) to escape the bracket, if it is part of a data field name. For example, a data field named `Field[1]` would be referenced as `Fields.[Field\\[1\\]]`. Another option for accessing the values in the fields collection is the global [Fields function](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/expressions/expressions-reference/functions/overview). When the DataSource is a collection of objects that don't contain named fields, for example, an array of integers/strings, you may access the collection items in the Report Expressions as `= Fields.Item` or `= Fields("Item")`. ## Parameters Represents the collection of report parameters, each of which can be single-value or multi-value. See [report parameter configuration](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/report-parameters/overview). Examples: * `=Parameters.Product.Value` - returns the actual `Value` of the report parameter with the name Product. * `=Parameters.Product.Label` - when the parameter Product has AvailableValues, returns its property `AvailableValues.DisplayMember`. When there are no AvailableValues or the DisplayMember is not specified, it falls back to the actual `Value` of the parameter. * `=Parameters.Product.Text` - returns the property `Text` of the report parameter with the name Product. When Text is not specified it displays the `Name` of the parameter, in this example, *Product*. Another option for accessing the report parameters' collection is the global [Parameters function](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/expressions/expressions-reference/functions/report-functions). ## Environment Represents a read-only type that contains information about the environment in which the reporting engine works. Contains two properties: `OperatingSystem` and `GraphicsEngine`. * `OperatingSystem` returns the identifier of the operating system in which the current application is running, as provided by the [OperatingSystem.VersionString property](https://learn.microsoft.com/en-us/dotnet/api/system.operatingsystem.versionstring) (e.g. 'Microsoft Windows NT 6.2.9200.0'). * `GraphicsEngine` returns a [GraphicsEngine API member](https://www.telerik.com/products/reporting/documentation/api/telerik.drawing.contract.graphicsengine) representing the currently used graphics engine. Available values: `Gdi` and `Skia`, accessible also through the **ReportingConstants.GraphicsEngine** options. Example: `=Switch(Environment.GraphicsEngine, GraphicsEngine.Gdi, "Using GDI", GraphicsEngine.Skia, "Using Skia", "N\A")` ## ExecutionTime A [DateTime](https://learn.microsoft.com/en-us/dotnet/api/system.datetime) instance containing the date and time of the moment when the current report started its processing by the reporting engine. ## PageNumber The current page number. It can be used only in the page header and footer. ## PageCount The total number of pages in the report that can be used only in the page header and footer. > note The page numbering behavior in a report contained in a report book may be controlled through the [PageNumberingStyle property](https://www.telerik.com/products/reporting/documentation/api/telerik.reporting.report#Telerik_Reporting_Report_PageNumberingStyle). ## RenderingFormat Represents the runtime rendering extension currently used to render the report. For information regarding the available child properties, check out the [RenderingFormat API reference](https://www.telerik.com/products/reporting/documentation/api/telerik.reporting.processing.renderingformat) or use the Expression Builder dialog. This global object will be populated while rendering the report in any report viewer or programmatically. The object will not be available in the ReportParameters properties evaluation as the parameters get evaluated before the rendering operation gets started. It is strongly recommended to use this property only for report visual output customizations and not for data retrieval parameterization, as the report data gets cached between the rendering operations for desktop viewers. Thus, using it will not lead to the desired effect. ## ReportItem The current processing item in which context the expression is evaluated. The object is not evaluated when the processing item is not available, i.e. when using it in report parameters. The `ReportItem` is an **object** passed from each item to its children. The `ReportItem.DataObject` in particular holds the data of the parent item, which makes it available to its children. If the parent item is a [data item](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/data-items/overview) with groups, only the group data is passed as `ReportItem.DataObject` to the corresponding groups and the items within these groups. When the child is a [data item](https://www.telerik.com/products/reporting/documentation/designing-reports/connecting-to-data/data-items/overview), it passes as `ReportItem.DataObject` its own data to its children. If the child isn't a data item and doesn't have a DataSource, it passes the `ReportItem.DataObject` received from its parent to its children. For example, the `Fields` from a Table DataSource are passed as `ReportItem.DataObject` to its cells' items, e.g. TextBoxes. Therefore, in these no-data items, the Expression `=Fields.fieldName` is equivalent to the Expression `=ReportItem.DataObject.fieldName`. On the Table item, though, the `ReportItem.DataObject` comes from its parent, for example, from the Report item. For that reason, `=ReportItem.DataObject.fieldName` is different from `=Fields.fieldName` in the Table. The `Fields` **function** represents the Table DataSource, whereas the `ReportItem.DataObject` **object** represents its parent (e.g. Report) DataSource. The `ReportItem.IsRepeated` property, introduced in version `20.0.26.211`, is available for report items (such as TextBoxes) placed within Table, Crosstab, and List group headers or footers. It indicates whether the group containing the item is being repeated on a page (for example, when a group header or footer is configured to repeat on every page). This property returns `True` when the group is repeated, and `False` otherwise. This is useful for conditionally displaying content based on whether the group appears for the first time or as a repeated instance. For example, `=Fields.ProductCategory + IIf(ReportItem.IsRepeated, ".........", "")` displays "Category Name........." when the group header is repeated. For detailed instructions on implementing this functionality, see [how to display continued text for repeated table group headers](https://www.telerik.com/products/reporting/documentation/knowledge-base/display-continued-text-repeatable-group-headers). For information regarding the available processing ReportItem properties, check out the corresponding processing item API reference. ## ReportDefinition The current report definition. For information regarding the available Report definition properties, check out the [Report API reference](https://www.telerik.com/products/reporting/documentation/api/telerik.reporting.report). ## UserIdentity [UserIdentity](https://www.telerik.com/products/reporting/documentation/api/telerik.reporting.processing.useridentity) provides structured information about the user, such as Name, AuthenticationType, and authentication status, and offers a Context dictionary for custom data. This property is designed to be used in web projects that utilize the Telerik Reporting REST API. It returns the main identity for this user, such as their username or authentication type. In a web application (ASP.NET Core or MVC), reports are usually served through a ReportsController, which handles HTTP requests from the report viewer (HTML5 Viewer, Blazor Viewer, etc.) to render and deliver the report. The ReportsController receives an HTTP request from the client asking for a report. Inside the controller, the method "GetUserIdentity()" is invoked to retrieve information about the user, currently logged into the web application. By default, this method obtains the user details from the HttpContext.User.Identity instance. Since the HttpContext provides access to the current HTTP request and response, the controller logic uses the identity information from the request to populate a UserIdentity instance. The method is declared as virtual, allowing the developers to override it and provide a custom implementation if needed. This global object will be populated for all web report previews based on the HTML5 report viewer. The default user identity resolution can be substituted for each report rendering service by overriding the corresponding GetUserIdentity method. When exporting a report programmatically, the global object can be populated by setting the static [UserIdentity.Current property](https://www.telerik.com/products/reporting/documentation/api/telerik.reporting.processing.useridentity#Telerik_Reporting_Processing_UserIdentity_Current). ### UserIdentity Properties To access the user identity in Telerik Reports, you can leverage the UserIdentity class provided by Telerik Reporting. This allows you to retrieve details such as the user's `name`, `authentication` status, and other `context-specific` information. | Name | Description | | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | AuthenticationType | Indicates the type of authentication used. Gets or sets a string value that specifies the authentication mechanism applied for the current user session (e.g., Cookie for server-based login or Bearer for token-based authentication) | | Context | Provides access to the context collection for storing and retrieving user-specific objects | | Current | Gets or sets the UserIdentity context that defines the user-specific information used during report processing and expression evaluation. For server viewer technologies, the value is resolved automatically. Developers can override this behavior. It can be accessed either through the static member or by using an expression like =UserIdentity.Name. | | IsAuthenticated | Indicates whether the user has been authenticated | | Name | Returns the name of the user |