Bio::Factory::ObjectBuilderI - Interface for an object builder


Give standard usage here


An object builder is different from an object factory in that it accumulates information for the object and finally, or constantly, depending on the implementation, builds the object. It also allows for implementations that can tell the information feed in which kind of information the builder is interested in which not. In addition, the implementation may choose to filter, transform, or completely ignore certain content it is fed for certain slots.

Implementations will hence be mostly used by stream-based parsers to parse only desired content, and/or skip over undesired entries.


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AUTHOR - Hilmar Lapp

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The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _


 Title   : want_slot
 Usage   :
 Function: Whether or not the object builder wants to populate the
           specified slot of the object to be built.

           The slot can be specified either as the name of the
           respective method, or the initialization parameter that
           would be otherwise passed to new() of the object to be

 Example :
 Returns : TRUE if the object builder wants to populate the slot, and
           FALSE otherwise.
 Args    : the name of the slot (a string)


 Title   : add_slot_value
 Usage   :
 Function: Adds one or more values to the specified slot of the object
           to be built.

           Naming the slot is the same as for want_slot().

           The object builder may further filter the content to be
           set, or even completely ignore the request.

           If this method reports failure, the caller should not add
           more values to the same slot. In addition, the caller may
           find it appropriate to abandon the object being built

 Example :
 Returns : TRUE on success, and FALSE otherwise
 Args    : the name of the slot (a string)
           parameters determining the value to be set


 Title   : want_object
 Usage   :
 Function: Whether or not the object builder is still interested in
           continuing with the object being built.

           If this method returns FALSE, the caller should not add any
           more values to slots, or otherwise risks that the builder
           throws an exception. In addition, make_object() is likely
           to return undef after this method returned FALSE.

 Example :
 Returns : TRUE if the object builder wants to continue building
           the present object, and FALSE otherwise.
 Args    : none


 Title   : make_object
 Usage   :
 Function: Get the built object.

           This method is allowed to return undef if no value has ever
           been added since the last call to make_object(), or if
           want_object() returned FALSE (or would have returned FALSE)
           before calling this method.

           For an implementation that allows consecutive building of
           objects, a caller must call this method once, and only
           once, between subsequent objects to be built. I.e., a call
           to make_object implies 'end_object.'

 Example :
 Returns : the object that was built
 Args    : none