The CodeFree
Integration Solution
Invu's CodeFree Integration was released
in December 2000. This satisfied two main requirements.
It allowed a partner or customer to develop their own
graphical user interface that could , without any extra
programming overheads, drive the Invu document management
software to select previously-stored documents, optionally
display them, and return the values of selected attributes.
The second requirement was to perform the same tasks for
any set of windows selected from those displayed by a
commercial software product, so that these wndows would
effectively provide a GUI onto the Invu system. Technically,
both requirements are satisfied by the same technique
of intercepting windows messages generated when mouse-clicks
are detected inside windows. The windows involved are
identified by their title strings and by those of their
ancestors which, unlike Windows handles, do not vary from
run to run. Individual controls, such as buttons and edit
boxes, within the windows are identified by the same method,
or by their coordinate positions. Once a window has been
identified and its handle obtained, any variable text
it contains can be obtained, and used to address the Invu
database. Similarly, return values of pre-selected Invu
attributes can be written to edit boxes in the client
program.
The technical details of the last two paragraphs
remain completely hidden from the customer. They are aware
only of a Training Phase where the trainer must mouse-click
on the buttons, scrolling lists and edit boxes in the
client windows they want to use to control the Invu accesses,
associating each with an Invu attribute that they select
from a scrolling list.
The trainer can optionally choose to display
the selected document and can choose attributes for writing
back to selected edit boxes in the client. There are additional
facilities to allow the values of selected attributes
to be fixed at training time, which is very useful in
restricting access to a particular area of the Invu database.
Also, the values of selected attributes can be carried
across from values set during an earlier Invu access.
This allows a set of attribute values to be collected
from across multiple client windows, and then used together
to select an Invu document. The attribute values from
earlier windows in the sequence will persist whilst an
attribute value from the latest window is varied between
accesses.
At run-time, the pre-trained Invu access
is triggered by mouse clicking on an existing button,
piece of static text or edit box, and the document display
and / or the return value display occurs within a very
short period of time. Where multiple documents match the
input attribute values, these documents are listed for
selection within a scrolling list, together with their
Invu attribute values. Alternatively, the matching documents
can be displayed in variable-sized sets, using multiple
viewer windows, and providing a button to display the
next set. It is even possible to suppress document display
and write back selected attribute values of selected documents
at up to 10 documents per second. This would permit the
client program to loop round reading these values and
transferring them into its own database.
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