[Overview][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'LazHelpIntf' (#lcl)

# THelpDatabase

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Provides support for integrating a collection of related help topics with a table of contents.

## Declaration

Source position: lazhelpintf.pas line 314

`type THelpDatabase = class(TComponent)`
`protected`
`procedure SetSupportedMimeTypes(); virtual;` |  | Sets the value in the SupportedMimeTypes property.
`procedure AddSupportedMimeType(); virtual;` |  | Adds a MIME type entry to the list in SupportedMimeTypes.
`public`
`constructor Create(); override;` |  | Constructor for the class instance.
`destructor Destroy; override;` |  | Destructor for the class instance.
`procedure Reference;` |  | Increments the number of references for the class instance.
`procedure RegisterSelf;` |  | Ensures that the LCL Help system has been initialized.
`procedure Release;` |  | Decrements the internal reference count for the help database`
`procedure UnregisterSelf;` |  |
`function Registered;` |  | Indicates if the list of help databases has been initialized for the database instance.
`function CanShowTableOfContents; virtual;` |  | Determines if a Table of Contents node is available for the help database.
`procedure ShowTableOfContents; virtual;` |  | Displays the Table of Contents in the TOCNode for the help database.
`procedure ShowError(); virtual;` |  | Displays an error message using the help manager, or raises an exception.
`function ShowHelp(); virtual;` |  |
`function ShowHelpFile(); virtual;` |  | Displays a help topic with the specified file name.
`function SupportsMimeType(); virtual;` |  | Determines is the specified MIME type is supported in the help database.
`function GetNodesForKeyword(); virtual;` |  | Creates or updates a list of help nodes using the specified help HelpKeyword.
`function GetNodesForDirective(); virtual;` |  |
`function GetNodesForContext(); virtual;` |  | Creates or updates the list of help nodes for the specified help context.
`function GetNodesForPascalContexts(); virtual;` |  | Creates or updates a list of nodes for the specified Pascal help GetNodesForPascalContexts.
`function GetNodesForClass(); virtual;` |  | Creates or updates a list of help nodes for the specified class.
`function GetNodesForMessage(); virtual;` |  | Creates or updates a list of help nodes matching the specified message.
`function FindViewer(); virtual;` |  | Gets the help viewer which supports the specified MIME type.
`procedure RegisterItem();` |  | Adds the specified item to the search items for the help database.
`procedure RegisterItemWithNode();` |  | Adds a search item to the help database for the specified help node.
`procedure RegisterFileItemWithNode();` |  | Adds a search item to the help database for the source file with the specified file name.
`procedure UnregisterItem();` |  | Removes the specified item from the search items for the help database.
`procedure UnregisterAllItems;`
`function RegisteredItemCount;` |  |
`function GetRegisteredItem();` |  | Gets the number of registered search items for the help database.
`procedure Load(); virtual;` |  |
`procedure Save(); virtual;` |  |
`function GetLocalizedName; virtual;` |  | Gets the localized name (ID) for the help database.
`property Databases: THelpDatabases; [rw]` |  | Help databases registered for use with the LCL help manager.
`property ID: THelpDatabaseID; [rw]` |  | Unique identifier for the hep database.
`property SupportedMimeTypes: TStrings; [r]` |  | Contains the list of MIME types supported in the help database.
`property BasePathObject: TObject; [rw]` |  | Represents the base path for the help database.
`property TOCNode: THelpNode; [rw]` |  | Help node with the Table of Contents for the help database.
`property AutoRegister: Boolean; [rw]` |  | Indicates if the help database is automatically registered at run-time.
`property OnFindViewer: TOnHelpDBFindViewer; [rw]` |  | Event handler signalled to locate the viewer for the help database.
`end;`

## Inheritance

`THelpDatabase` |  | Provides support for integrating a collection of related help topics with a table of contents.
`TComponent`
?
`TObject`