# IMoniker - Item Moniker Implementation

Item monikers are used to identify objects within containers, such as a portion of a document, an embedded object within a compound document, or a range of cells within a spreadsheet. Item monikers are often used in combination with file monikers; a file moniker is used to identify the container while an item moniker is used to identify the item within the container.

An item moniker contains a text string; this string is used by the container object to distinguish the contained item from the others. The container object must implement the IOleItemContainer interface; this interface enables the item moniker code to acquire a pointer to an object, given only the string that identifies the object.

##### When to Use

If you’re a moniker client (that is, you’re using a moniker to get an interface pointer to an object), you typically don’t need to know the class of the moniker you’re using; you simply call methods using an IMoniker interface pointer.

If you’re a moniker provider (that is, you’re handing out monikers that identify your objects to make them accessible to moniker clients), you must use item monikers if the objects you’re identifying are contained within another object and can be individually identified using a string. You’ll also need to use another type of moniker (for example, file monikers) in order to identify the container object.

To use item monikers, you must use the CreateItemMoniker function to create the monikers. In order to allow your objects to be loaded when an item moniker is bound, the container of your objects must implement the IOleItemContainer interface.

The most common example of moniker providers are OLE applications that support linking. If your OLE application supports linking to objects smaller than a file-based document, you need to use item monikers. For a server application that allows linking to a selection within a document, you use the item monikers to identify those objects. For a container application that allows linking to embedded objects, you use the item monikers to identify the embedded objects.

Remarks

IMoniker::BindToObject
  If pmkToLeft is NULL, this method returns E_INVALIDARG. Otherwise, the method calls IMoniker::BindToObject on the pmkToLeft parameter, requesting an IOleItemContainer interface pointer. The method then calls IOleItemContainer::GetObject, passing the string contained within the moniker, and returns the requested interface pointer.
IMoniker::BindToStorage
  If pmkToLeft is NULL, this method returns E_INVALIDARG. Otherwise, the method calls IMoniker::BindToObject on the pmkToLeft parameter, requesting an IOleItemContainer interface pointer. The method then calls IOleItemContainer::GetObjectStorage for the requested interface.
IMoniker::Reduce
  This method returns MK_S_REDUCED_TO_SELF and passes back the same moniker.
IMoniker::ComposeWith
  If pmkRight is an anti-moniker, the returned moniker is NULL; if pmkRight is a composite whose leftmost component is an anti-moniker, the returned moniker is the composite after the leftmost anti-moniker is removed. If pmkRight is not an anti-moniker, the method combines the two monikers into a generic composite if fOnlyIfNotGeneric is FALSE; if fOnlyIfNotGeneric is TRUE, the method returns a NULL moniker and a return value of MK_E_NEEDGENERIC.
IMoniker::Enum
  This method returns S_OK and sets *ppenumMoniker to NULL.
IMoniker::IsEqual
  This method returns S_OK if both monikers are item monikers and their display names are identical (using a case-insensitive comparison); otherwise, the method returns S_FALSE.
IMoniker::Hash
  This method calculates a hash value for the moniker.
IMoniker::IsRunning
  If pmkToLeft is NULL, this method returns TRUE if pmkNewlyRunning is non-NULL and is equal to this moniker. Otherwise, the method checks the ROT to see whether this moniker is running.

  If pmkToLeft is non-NULL, the method calls IMoniker::BindToObject on the pmkToLeft parameter, requesting an IOleItemContainer interface pointer. The method then calls IOleItemContainer::IsRunning, passing the string contained within this moniker.

IMoniker::GetTimeOfLastChange
  If pmkToLeft is NULL, this method returns MK_E_NOTBINDABLE. Otherwise, the method creates a composite of pmkToLeft and this moniker and uses the ROT to access the time of last change. If the object is not in the ROT, the method calls IMoniker::GetTimeOfLastChange on the pmkToLeft parameter.
IMoniker::Inverse
  This method returns an anti-moniker (i.e., the results of calling CreateAntiMoniker).
IMoniker::CommonPrefixWith
  If the other moniker is an item moniker that is equal to this moniker, this method sets *ppmkPrefix to this moniker and returns MK_S_US; otherwise, the method calls the MonikerCommonPrefixWith function. This function correctly handles the case where the other moniker is a generic composite.
IMoniker::RelativePathTo
  This method returns MK_E_NOTBINDABLE and sets *ppmkRelPath to NULL.
IMoniker::GetDisplayName
  This method returns the concatenation of the delimiter and the item name that were specified when the item moniker was created.
IMoniker::ParseDisplayName
  If pmkToLeft is NULL, this method returns MK_E_SYNTAX. Otherwise, the method calls IMoniker::BindToObject on the pmkToLeft parameter, requesting an IOleItemContainer interface pointer. The method then calls IOleItemContainer::GetObject, requesting an IParseDisplayName interface pointer to the object identified by the moniker, and passes the display name to IParseDisplayName::ParseDisplayName.
IMoniker::IsSystemMoniker
  This method returns S_OK and indicates MKSYS_ITEMMONIKER.

See Also

CreateItemMoniker, IMoniker, IOleItemContainer