Object Serialisation
 

Hi there, can anyone please guide me on how to do object serialisation
in VBA?

Many Thanks
Lloyd

Object Serialisation
 

sorry but i can't understand what's object serialization.

could you explain it more in detail?

sorry again for not helping you

--
msn
---------------------------------------------
the best time to plant a tree was twenty years ago.
the second best time, is today - Chinese proverb



"pinkfloydfan" wrote:

Hi there, can anyone please guide me on how to do object serialisation
in VBA?

Many Thanks
Lloyd

Object Serialisation
 

http://en.wikipedia.org/wiki/Serialization

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

"timebird" wrote in message
...
sorry but i can't understand what's object serialization.

could you explain it more in detail?

sorry again for not helping you

--
msn
---------------------------------------------
the best time to plant a tree was twenty years ago.
the second best time, is today - Chinese proverb



"pinkfloydfan" wrote:

Hi there, can anyone please guide me on how to do object serialisation
in VBA?

Many Thanks
Lloyd

Object Serialisation
 

Timebird

I understand that serialization is the process whereby you store an
object on a hard drive in some readable format that it can be loaded
back in again should you so wish.

It would be very useful to me to know how to do this in VBA as I have
some pretty complicated objects that are somewhat memory intensive and
so would like to be able to store them permanently outside of RAM so I
don't have to keep re-creating them every time I open my application.

Thanks
Lloyd

Object Serialisation
 

If I understand, what you need to save is the data the VBA routine needs to
recreate an object from its class. This may be as simple as a text file with
a list of property names and corresponding values, which are saved and
loaded by the object or the code controlling the object.

The code will have to be able to distinguish from creating a new object of
the class and recreating a previously defined instance of the class.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"pinkfloydfan" wrote in message
oups.com...
Timebird

I understand that serialization is the process whereby you store an
object on a hard drive in some readable format that it can be loaded
back in again should you so wish.

It would be very useful to me to know how to do this in VBA as I have
some pretty complicated objects that are somewhat memory intensive and
so would like to be able to store them permanently outside of RAM so I
don't have to keep re-creating them every time I open my application.

Thanks
Lloyd

Object Serialisation
 

That sounds about right Jon

I think what I need is two additional methods (SerialiseObject &
UnserialiseObject): running the SerialiseObject method stores the raw
object data in a text file and conversely the UnserialiseObject method
loads the data back (either into an existing object or a new one).

So, can you give me some pointers on how to do that please?

Thanks a lot
Lloyd

Object Serialisation
 

Maybe think about using XML or some other structured type of text file.

What part do you need help with? Can you write/read a text file?

Can your objects be serialized to text? This is not always straightforward:
for example your object may have a property which refers to another object
(a custom object or a workbook for example): this would not be trivial to
persist to a file. Maybe you could describe the type of object you want to
serialize ?

Tim


"pinkfloydfan" wrote in message
oups.com...
That sounds about right Jon

I think what I need is two additional methods (SerialiseObject &
UnserialiseObject): running the SerialiseObject method stores the raw
object data in a text file and conversely the UnserialiseObject method
loads the data back (either into an existing object or a new one).

So, can you give me some pointers on how to do that please?

Thanks a lot
Lloyd

Object Serialisation
 

Thanks for the input Tim

Unfortunately, I am only familiar with VBA and don't have any
knowledge of other programming languages at this time. The specific
object I want to serialise has some simple core data that it uses to
create a path-dependent result. I store every step of the path in an
array and it not unusual to have between 250-1250 steps for a single
object.

This process is then repeated many thousands of times and all these
objects are stored in a master object / collection.

You can appreciate that I don't really want to wait a few minutes to
build the master object(s) each time I use my application and so was
looking for a way to store that data outside of Excel and re-load it
as I need it. Actually if this can be achieved efficiently I can
think of a lot of uses for this process.

Perhaps if anyone can guide me on how to write an object's properties
to a text file and read them back in that would be a good place to
start...or is there a more efficient method?

Many Thanks
Lloyd

Object Serialisation
 

If the contents of an array can be repesented as text then you could use
join() to convert the array into a text string and then write it to a text
file. Plenty of examples of wrting to a file to be had by searching this
newsgroup, so no need for me to repeat any of them here.

Or if you want something more structured then use an xml representation

<propertyname1
<valvalue1</val
<valvalue2</val
....
<valvalueX</val
</propertyname1

<propertyname2
......
</propertyname2

etc.

or write the values to an Excel sheet and use that as your cache.

You might want to investigate speeding up your object-building code though.
If the objects are built without a lot of user-input then it might be
quicker just to rebuild them from scratch.

Tim

"pinkfloydfan" wrote in message
oups.com...
Thanks for the input Tim

Unfortunately, I am only familiar with VBA and don't have any
knowledge of other programming languages at this time. The specific
object I want to serialise has some simple core data that it uses to
create a path-dependent result. I store every step of the path in an
array and it not unusual to have between 250-1250 steps for a single
object.

This process is then repeated many thousands of times and all these
objects are stored in a master object / collection.

You can appreciate that I don't really want to wait a few minutes to
build the master object(s) each time I use my application and so was
looking for a way to store that data outside of Excel and re-load it
as I need it. Actually if this can be achieved efficiently I can
think of a lot of uses for this process.

Perhaps if anyone can guide me on how to write an object's properties
to a text file and read them back in that would be a good place to
start...or is there a more efficient method?

Many Thanks
Lloyd

Object Serialisation
 

Ok Tim, thanks for your time, I think I have enough pointers to get me
started here

Object Serialisation
 

One of the easiest ways to store arrays is in an Excel worksheet. Loading a
large workbook takes a few seconds, but you can move arrays between the
sheet and VBA quickly, then processing the arrays in VBA is pretty fast.

' move data from Excel range to VBA array:
Dim vArrayInput As Variant
vArrayInput =
Workbooks("Book1.xls").Worksheets("Sheet2").Range( "C3:Q504").Value

' move data from VBA array to Excel range:
Dim vArrayOutput(RowMin To RowMax, ColMin To ColMax) As Variant ' or other
type
' populate vArrayOutput (not shown: do it according to your app)
Workbooks("Book3.xls").Worksheets("Sheet4").Range( "X200") _
.Resize(UBound(vArrayOutput,1) + 1 - LBound(vArrayOutput,1), _
UBound(vArrayOutput,2) + 1 - LBound(vArrayOutput,2)).Value =
vArrayOutput

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"pinkfloydfan" wrote in message
oups.com...
Thanks for the input Tim

Unfortunately, I am only familiar with VBA and don't have any
knowledge of other programming languages at this time. The specific
object I want to serialise has some simple core data that it uses to
create a path-dependent result. I store every step of the path in an
array and it not unusual to have between 250-1250 steps for a single
object.

This process is then repeated many thousands of times and all these
objects are stored in a master object / collection.

You can appreciate that I don't really want to wait a few minutes to
build the master object(s) each time I use my application and so was
looking for a way to store that data outside of Excel and re-load it
as I need it. Actually if this can be achieved efficiently I can
think of a lot of uses for this process.

Perhaps if anyone can guide me on how to write an object's properties
to a text file and read them back in that would be a good place to
start...or is there a more efficient method?

Many Thanks
Lloyd

Object Serialisation
 

Thanks Jon, that's an excellent idea.

Unfortunately, in this case it won't do as the arrays would be greater
than the size of the spreadsheet which leaves me having to split them
and work across more than one worksheet.

Instead, I'm looking into creating a structured text file which
includes some form of identifier/header for each property of each
object. I am hoping that I will then be able to load the object back
by going to each identifier in the text file and reading in the next
[line] of text.

I wonder if anybody else has ever done this before?

Lloyd