I have become convinced that early binding is "a good thing".
My technique for applying it is to declare a variable with type Object,
use typename to find the type and then redeclare the variable with that
type. However, that sometimes fails for no reason I can understand.

This is a cut-down example:

Public Sub TypeChange()
Const URL As String = "journeyplanner.tfl.gov.uk/user/" & _
"XSLT_TRIP_REQUEST2?language=en&sessionID=0" & _
"&type_origin=stop&name_origin=ANGEL" & _
"&type_destination=stop&name_destination=BANK"

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

TxURL URL ' Connect to application.internetexplorer and set Doc
Set Tables = Doc.getElementsByTagName("Table")
Debug.Print TypeName(Tables)
End Sub

This shows that Tables is set as a DispHTMLElementCollection
If I redeclare Tables As DispHTMLElementCollection,
the set statement fails with a Run-time error '13':
Type mismatch.

Why?

How do I get types of methods?
How do I get the definition of DispHTMLElementCollection?
(I can easily get member types with View\Locals Window.)

My hypothesis is that getElementsByTagName is declared to return a more
general type than DispHTMLElementCollection and that type mismatches.

This smaller example does not show the problem.;(
Dim Origin As DispHTMLElementCollection
Dim Destination As DispHTMLElementCollection

Set Destination = Origin


Light, please? ;)
--
Walter Briscoe

To use early binding you must have a reference set to the object library (Tools | References in the
VBE)
One library I found is the "Microsoft HTML Object Library".
It permits you to set a references to the "HTMLElementCollection"
--
Jim Cone
Portland, Oregon USA .
http://www.mediafire.com/PrimitiveSoftware .
(Data Options Excel add-in: Color, Delete, Insert: rows/dates/random data )




"Walter Briscoe"
wrote in message
...
I have become convinced that early binding is "a good thing".
My technique for applying it is to declare a variable with type Object,
use typename to find the type and then redeclare the variable with that
type. However, that sometimes fails for no reason I can understand.

This is a cut-down example:

Public Sub TypeChange()
Const URL As String = "journeyplanner.tfl.gov.uk/user/" & _
"XSLT_TRIP_REQUEST2?language=en&sessionID=0" & _
"&type_origin=stop&name_origin=ANGEL" & _
"&type_destination=stop&name_destination=BANK"

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

TxURL URL ' Connect to application.internetexplorer and set Doc
Set Tables = Doc.getElementsByTagName("Table")
Debug.Print TypeName(Tables)
End Sub

This shows that Tables is set as a DispHTMLElementCollection
If I redeclare Tables As DispHTMLElementCollection,
the set statement fails with a Run-time error '13':
Type mismatch.

Why?
How do I get types of methods?
How do I get the definition of DispHTMLElementCollection?
(I can easily get member types with View\Locals Window.)

My hypothesis is that getElementsByTagName is declared to return a more
general type than DispHTMLElementCollection and that type mismatches.

This smaller example does not show the problem.;(
Dim Origin As DispHTMLElementCollection
Dim Destination As DispHTMLElementCollection
Set Destination = Origin
Light, please? ;)
--
Walter Briscoe

In message of Tue, 20 Dec 2011 08:50:47 in
microsoft.public.excel.programming, Jim Cone
writes

To use early binding you must have a reference set to the object
library (Tools | References in the
VBE)
One library I found is the "Microsoft HTML Object Library".
It permits you to set a references to the "HTMLElementCollection"

Jim,
I understand that and already have a reference set to "Microsoft HTML
Object Library" as you have found.

That does not explain the Run-time error '13': Type mismatch in:
Dim Tables As DispHTMLElementCollection

....
Set Tables = Doc.getElementsByTagName("Table") ' gets Type mismatch.
--
Walter Briscoe

On Tue, 20 Dec 2011 11:32:26 +0000, Walter Briscoe wrote:

I have become convinced that early binding is "a good thing".
My technique for applying it is to declare a variable with type Object,
use typename to find the type and then redeclare the variable with that
type. However, that sometimes fails for no reason I can understand.

This is a cut-down example:

Public Sub TypeChange()
Const URL As String = "journeyplanner.tfl.gov.uk/user/" & _
"XSLT_TRIP_REQUEST2?language=en&sessionID=0" & _
"&type_origin=stop&name_origin=ANGEL" & _
"&type_destination=stop&name_destination=BANK"

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

TxURL URL ' Connect to application.internetexplorer and set Doc
Set Tables = Doc.getElementsByTagName("Table")
Debug.Print TypeName(Tables)
End Sub

This shows that Tables is set as a DispHTMLElementCollection
If I redeclare Tables As DispHTMLElementCollection,
the set statement fails with a Run-time error '13':
Type mismatch.

Why?

How do I get types of methods?
How do I get the definition of DispHTMLElementCollection?
(I can easily get member types with View\Locals Window.)

My hypothesis is that getElementsByTagName is declared to return a more
general type than DispHTMLElementCollection and that type mismatches.

This smaller example does not show the problem.;(
Dim Origin As DispHTMLElementCollection
Dim Destination As DispHTMLElementCollection

Set Destination = Origin


Light, please? ;)

Googling for the various properties/methods will usually detect a page in the MSDN library for the various definitions.

In your specific example,

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

did you also try: Dim Tables As HTMLElementCollection

I don't even see DispHTMLElementCollection as a valid object in the drop down list.

In message of Wed, 21 Dec
2011 08:12:15 in microsoft.public.excel.programming, Ron Rosenfeld
writes
On Tue, 20 Dec 2011 11:32:26 +0000, Walter Briscoe
wrote:

I have become convinced that early binding is "a good thing".
My technique for applying it is to declare a variable with type Object,
use typename to find the type and then redeclare the variable with that
type. However, that sometimes fails for no reason I can understand.

This is a cut-down example:

Public Sub TypeChange()
Const URL As String = "journeyplanner.tfl.gov.uk/user/" & _
"XSLT_TRIP_REQUEST2?language=en&sessionID=0" & _
"&type_origin=stop&name_origin=ANGEL" & _
"&type_destination=stop&name_destination=BANK"

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

TxURL URL ' Connect to application.internetexplorer and set Doc
Set Tables = Doc.getElementsByTagName("Table")
Debug.Print TypeName(Tables)
End Sub

This shows that Tables is set as a DispHTMLElementCollection
If I redeclare Tables As DispHTMLElementCollection,
the set statement fails with a Run-time error '13':
Type mismatch.

Why?

How do I get types of methods?
How do I get the definition of DispHTMLElementCollection?
(I can easily get member types with View\Locals Window.)

My hypothesis is that getElementsByTagName is declared to return a more
general type than DispHTMLElementCollection and that type mismatches.

This smaller example does not show the problem.;(
Dim Origin As DispHTMLElementCollection
Dim Destination As DispHTMLElementCollection

Set Destination = Origin


Light, please? ;)

Googling for the various properties/methods will usually detect a page
in the MSDN library for the various definitions.

In your specific example,

Dim Tables As Object ' Array of tables in ie.document
' DispHTMLElementCollection gets assignment error

did you also try: Dim Tables As HTMLElementCollection

I did not. What would have led me to do so? I have since tried and also
got a type mismatch.


I don't even see DispHTMLElementCollection as a valid object in the
drop down list.

What drop down list?
Do you mean View/Object Browser also accessible via F2.
I found nothing relevant there under <All Libraries.
After I stepped into my sub, MSHTML, among other libraries, was added to
<All Libraries and HTMLElementCollection was viewable.

I have
Dim Doc As HTMLDocument ' IE.Document
' Needs Tools/References/HTML Object Library

Ah! Now I begin to see. HTMLDocument has getElementsByTagName as a
member which is specified as
Function getElementsByTagName(v As String) as IHTMLElementCollection.

When I do
Dim Tables As IHTMLElementCollection
Set Tables = Doc.getElementsByTagName("Table") runs without an error.

Curiously, typename(tables) is also "DispHTMLElementCollection".
Where does that come from?

Thank you for sending me in good directions.

I quote myself and give some answers:
How do I get types of methods?
View/Object Browser also accessible via F2.

How do I get the definition of DispHTMLElementCollection?
(I can easily get member types with View\Locals Window.)
I don't know but found IHTMLElementCollection serves my need.
It seems DispHTMLElementCollection is undocumented.


My hypothesis is that getElementsByTagName is declared to return a more
general type than DispHTMLElementCollection and that type mismatches.

I can look up the specification of a type if I know where it is
specified. How do I look it up without such knowledge?

Thanks again. I am happier with early binding than I was. ;)
--
Walter Briscoe

On Wed, 21 Dec 2011 15:22:16 +0000, Walter Briscoe wrote:

I don't even see DispHTMLElementCollection as a valid object in the
drop down list.

What drop down list?

If I have set the reference appropriately (Tools/References), when I type, for example

Sub foo()
"Dim Table as " (without the quotes but WITH the trailing space)
end sub

I am presented with a drop down list containing all of the legitimate choices for type assignment.

Also, most of the time, after typing a dot:

Dim rg as Range
Set rg = Range("A1"). After typing that terminal Dot, I will be presented with a drop-down list of possible Range properties

I don't recall what that is call, but to me, that help facility is the major incentive for early binding.

Ron Rosenfeld presented the following explanation :
On Wed, 21 Dec 2011 15:22:16 +0000, Walter Briscoe
wrote:

I don't even see DispHTMLElementCollection as a valid object in the
drop down list.

What drop down list?

If I have set the reference appropriately (Tools/References), when I type,
for example

Sub foo()
"Dim Table as " (without the quotes but WITH the trailing space)
end sub

I am presented with a drop down list containing all of the legitimate choices
for type assignment.

Also, most of the time, after typing a dot:

Dim rg as Range
Set rg = Range("A1"). After typing that terminal Dot, I will be
presented with a drop-down list of possible Range properties

I don't recall what that is call, but to me, that help facility is the major
incentive for early binding.

I believe the term for this is "context sensitive", where the VBE
implements "auto-sense" for entering valid properties/methods/constants
etcedera!

--
Garry

Free usenet access at http://www.eternal-september.org
ClassicVB Users Regroup! comp.lang.basic.visual.misc

On Wed, 21 Dec 2011 12:57:42 -0500, GS wrote:

I believe the term for this is "context sensitive", where the VBE
implements "auto-sense" for entering valid properties/methods/constants
etcedera!

Bingo.

Do you have any idea why it sometimes works and sometimes doesn't?

eg:

Sub foo()
Dim w As Worksheet
Set w = ThisWorkbook.Worksheets(1)

'does NOT show context sensitive prompts
Worksheets(1).Range("A1").Value = 2

'does show context sensitive prompts
w.Range("a2").Value = 3

End Sub