The Excel Add-In (TOSC RTCache.xla) is capable of both importing and exporting
data using OLE automation. OLE automation is significantly more efficient than
using traditional DDE approaches to similar problems. Import and Export is
achieved using the functions RTImport() and RTExport(). These functions are
embedded directly into the formula cells of the sheet. This is suitable for use
on new spreadsheets. However, where the spreadsheets already exist, the add-in
also provides an alternative export facility using Dataworks Enterprise DDE
Client software. RTImport() is a function which can be applied to spreadsheet cells or arrays.
Where there is a lot of data to be import, the array approach is more
efficient. Two spreadsheets are provided on the distribution CD to illustrate
these two approaches using the same data set. Currencies.xls imports data on a
cell-by-cell basis, CurArray.xls on a array basis. The function takes three
arguments, the name of the source and instrument and a variant containing the
field or fields to be imported. For instance, the formula would import the Euro BID field from SelectFeed into the current cell. Any of
the arguments can be substituted for with cell names or addresses. In the case
of the example sheet, we are importing the values using other fields to hold
the names of source instruments and fields. This capability also enables us to
import on a row by row basis. Suppose that we created a row of field names to
be imported. This range could be provided as a third argument and the formula
could be used as an array formula populating an entire row of the spreadsheet
at a time. The following formula is common: where $A$1 is the name of source, $A4 the name of the instrument and $B$3:$I$3
is a range representing field names. This is particular convenient since it
allows tables to be set up containing a column of item names and a row of field
names and the sheet to be updated using simple dragging of cells. Updates to cells using RTImport() are generated using a timer. Each time the
timer fires (every three seconds or so), the add-in will update all the cells
in the table that contain the function assuming automatic recalculation has
been selected. In many cases, the timer is a better approach than real-time
update as it is more deterministic in performance terms and therefore more
predictable. NOTE: Excel does not provide a mechanism to indicate that an invariant function
has changed value on a cell-by-cell basis. An invariant function is a function
whose arguments are constant. Excel assumes that given a set of constant
arguments to a function, calls to that function will always return the same
result. Excel optimises invariant functions by not recalculating the cell
value, since it already knows the result. Invariant functions can be marked
‘volatile’ to mean that if there is any change to the sheet all cells
containing the function need to be recalculated. This is akin to a function
like Now() where if anything updates, all cells containing the Now() formula
will also update. This is more time consuming than the use of a simple timer. The Excel add-in also provides a spreadsheet export facility to allow the sheet
to publish data directly using Dataworks Enterprise Publishing System. There
are two means to export data from a spreadsheet, the RTExport() function and
Dataworks Enterprise DDE Client. RTExport() uses an OLE automation approach to publish data. Like RTImport, the
export function can be used on a cell or row basis, using much the same
mechanisms. The RTExport() function takes four parameters, the first three
being the same as RTImport and the last one or more variant values for the
fields being exported. The example spreadsheet, Publish.xls illustrates its
use. Since spreadsheet publishing is likely to be a small-scale affair,
RTExport() exposes the source as a publishing source, assuming the use of
Dataworks Enterprise Publishing System. RTExport() returns the same values as
put in, so that the function can easily be embedded into a sheet. The Components of Dataworks Enterprise DDE System The add-in also provides toolbar buttons that allow sections of spreadsheet to
be exported using DDE via Dataworks Enterprise DDE client. This is mainly
useful where the spreadsheets are legacy applications. The RTExport() function
relies on embedding the results of the export into the cells of the
calculations. For legacy sheets it may be better to use Dataworks Enterprise
DDE Client. The add-in provides a pair of toolbar buttons to allow a selection
from a spreadsheet to be exposed as a collection of instruments or pages via
the DDE client. The word add-in (PubDoc.dot) is a simple template containing VBA code that
allows a Word document to be published as a series of real-time pages. The
accompanying example PubDoc.doc explains how it works in detail. To use the
add-in, select Templates and Add-Ins from the Tools menu and import the add-in.
A button should appear on the toolbar. Pressing this button will prompt for a
source and item name. On pressing OK, the template scans the current document
splitting it into 25x80 pages and publishing those pages with links between
them. The source is always mounts as a publishing source and the output pages
marked permanent so they can be stored by a publishing server even when the
Word document has been closed. This component was part of the first release of the product. This component depends on the installation of Office applications such as Excel
and Word. Configuration of this component is simply to add it to the list of Add-Ins in
Excel or to reference the appropriate document template in Word. The add-ins
are installed in the Primark\Platform\Data area of the installation. None. *DISCLAIMER: The changes are only possible proposals and
represent neither "work in progress" nor work that is scheduled for a
future release. Details of product roadmaps and current development shoudl be
directed through the normal reporting channels.Dataworks Enterprise Office Integration
Dataworks Enterprise Office Integration consists of module
design to allow Excel and Word to publish and subscribe to data through
Dataworks Enterprise.
Excel
Spreadsheet Import
=RTImport(‘SelectFeed’, ‘EUR=’, ‘BID’)
{=RTImport($A$1, $A4, $B$3:$I3)}
Spreadsheet Export
Word Add-In
History
Dependencies
Configuration
Known Problems
Futures*