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How do I use YAXO or any XML lib to find nodes?

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Tim M

How do I use YAXO or any XML lib to find nodes?

Help: I can't figure out how to use YAXO - the examples show how to
parse a document (and I get that far) but how do I do useful things
with the document?

The #tagsNamed... and #findFirstTagNamed: methods don't seem to find
anything when I use them.

Furthermore, I don't see any generic way to visit all nodes and do the
comparison myself (#printXMLOn: is the only thing close, but it seems
pretty tied to printing XML and not a generic way to visiting the
nodes)?

As I don't see any XPath implementations, I must be missing something
big.

Can someone give me a pointer?

Basically I have a little test document, and I'd like to get to the
span node called #main, and ideally replace its contents with another
node (e.g. a div). This should be pretty trivial to do, but I am stuck.
I started writing my own visit methods but I must be missing something?

<html>
<head>
<title>My Title</title>
</head>
<body>
<div id="test">
<p>This is <b>some</b> text</p>
<p>Second paragraph</p>
<span editable="true" id="main">edittable text</span>
<br/>
</div>
</body>
</html>

Tim

hboon@motionobj.com

Re: How do I use YAXO or any XML lib to find nodes?

Did you try #elementsDoAndRecurse: ?

--
Hwee Boon

Tim M

Re: How do I use YAXO or any XML lib to find nodes?

hmmm I don't see: #elementsDoAndRecurse:

And I appear to be using the latest version from DolphinHarbour?

#entityAt:looked promising but no go?

Tim

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

"TimM" <[hidden email]> wrote:

> hmmm I don't see: #elementsDoAndRecurse:
>
> And I appear to be using the latest version from DolphinHarbour?
>

Hi Tim

I think I must come clean here. I did a crude port of Yaxo to Dolphin last
year, because it was needed to port the SqueakMap HTML Parser, the latter
being my real interest. I passed the results to Hwee Boon, who was
interested in the XML stuff, so I expect he is mentioning
#elementsDoAndRecurse: because he found it in my version. It is an instance
method I added to the class XMLNodeWithElements, because I found the same
problem you did with visiting the whole tree. I did not put in a method
comment admitting to authorship, so Hwee Boon may not have realised it was
mine.

The code of the method is pretty trivial:

elementsDoAndRecurse: aBlock

elements

ifNotNil: [:x|

self elements do: [:each | aBlock value: each.

(each respondsTo: #elements) ifTrue:[ each
elementsDoAndRecurse: aBlock]]]

(The apparently redundant argument in the block above deals with a
difference in syntax between Squeak and Dolphin in handling ifNotNil:, which
takes a zero-argument block in Squeak and a one-argument block in Dolphin.)

By the way, although you talk about XML parsing, the example in your first
post is pure HTML. If this is typical of your material, you may want the
HTML parser as well as Yaxo. My port to Dolphin is currently hosted by Bill
Schwab (http://needle.anest.ufl.edu/anest4/bills/Smalltalk.htm) if you want
to try it. Come back if any queries.

Best wishes

Peter Kenny

Sean M-7

Re: How do I use YAXO or any XML lib to find nodes?

> elementsDoAndRecurse: aBlock
>
> elements
>
> ifNotNil: [:x|
>
> self elements do: [:each | aBlock value: each.
>
> (each respondsTo: #elements) ifTrue:[ each
> elementsDoAndRecurse: aBlock]]]
>
> (The apparently redundant argument in the block above deals with a
> difference in syntax between Squeak and Dolphin in handling ifNotNil:,
> which
> takes a zero-argument block in Squeak and a one-argument block in
> Dolphin.)

The ifNotNil one arg block is nice when you need to expect nil returns from
message sends

self elements ifNotNil: [ :e | e doSomething ].

Squeak doesn't support this (IMO it should).

However, Dolphin 6, like VisualWorks, now supports both forms. so you can
write:

elements ifNotNil: [ :e | ]
or
elements ifNotNil: [ ]

Dolphin 5 hits you with an error if you try and do that.

TimM-3

Re: How do I use YAXO or any XML lib to find nodes?

Hey thanks guys, so it would seem that Peter's method would be better
written as:

elements
ifNotNil: [:x|
x do: [:each | aBlock value: each.....

Although, in my version of Yaxo, #elements is defined as:

elements
^self entities collect: [:each | each value]

So I had to change the method to:

self elements ifNotNil: [ :x |

however, if elements is defined as above.... it won't ever be nil (you will
get a walkback if entities is nil)? So you might as well do:

self elements do: [:each | ....

Tim

"Sean M" <[hidden email]> wrote in message
news:7Qvef.548$[hidden email]...

>> elementsDoAndRecurse: aBlock
>>
>> elements
>>
>> ifNotNil: [:x|
>>
>> self elements do: [:each | aBlock value: each.
>>
>> (each respondsTo: #elements) ifTrue:[ each
>> elementsDoAndRecurse: aBlock]]]
>>
>> (The apparently redundant argument in the block above deals with a
>> difference in syntax between Squeak and Dolphin in handling ifNotNil:,
>> which
>> takes a zero-argument block in Squeak and a one-argument block in
>> Dolphin.)
>
> The ifNotNil one arg block is nice when you need to expect nil returns
> from message sends
>
> self elements ifNotNil: [ :e | e doSomething ].
>
> Squeak doesn't support this (IMO it should).
>
> However, Dolphin 6, like VisualWorks, now supports both forms. so you can
> write:
>
> elements ifNotNil: [ :e | ]
> or
> elements ifNotNil: [ ]
>
> Dolphin 5 hits you with an error if you try and do that.
>

TimM-3

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by Peter Kenny-2

> method I added to the class XMLNodeWithElements, because I found the same
> problem you did with visiting the whole tree.

Your method was exactly what I was writing (except yours is better so I'll
keep it ;-)

This does beg the question - what is the point of the #tagsNamed... and
#firstTagNamed: methods?

They seem pretty pointless as they don't recurse down any of the levels of
tags? In fact other than successfully parsing the document it seems that
YAXO doesn't really do anything.

When searching the archives on people using YAXO it seems that many have
switched from MSXML to it, but I am left wondering how they are using it.
Maybe just for really simple things like:

<customer>
<name>Tim</name>
<age>25</age>
</customer>

But even then those methods don't find <age>.... so whats to the point?

Tim

Esteban A. Maringolo-3

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by Sean M-7

Sean M escribió:
>>elementsDoAndRecurse: aBlock

>>(The apparently redundant argument in the block above deals with a
>>difference in syntax between Squeak and Dolphin in handling ifNotNil:,
>>which
>>takes a zero-argument block in Squeak and a one-argument block in
>>Dolphin.)

> The ifNotNil one arg block is nice when you need to expect nil returns from
> message sends
> self elements ifNotNil: [ :e | e doSomething ].

> Squeak doesn't support this (IMO it should).

Indeed it does, but using #ifNotNilDo: monadicValuable
VisualAge has #ifNil: #ifNotNil: with the same semantics as Dolphin,
but doesn't have an implementation of #ifNil:ifNotNil: :-)

However, Dolphin optimizes the sends of #ifNil:/#ifNotNil:, right?

> However, Dolphin 6, like VisualWorks, now supports both forms. so you can
> write:
> elements ifNotNil: [ :e | ]
> or
> elements ifNotNil: [ ]

Hey! I didn't noticed that :-)
Thank you

Regards,

--
Esteban.

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by TimM-3

"TimM" <[hidden email]> wrote:

> Hey thanks guys, so it would seem that Peter's method would be better
> written as:
>
> elements
> ifNotNil: [:x|
> x do: [:each | aBlock value: each.....
>
> Although, in my version of Yaxo, #elements is defined as:
>
> elements
> ^self entities collect: [:each | each value]
>
>
> So I had to change the method to:
>
> self elements ifNotNil: [ :x |
>
> however, if elements is defined as above.... it won't ever be nil (you

will
> get a walkback if entities is nil)? So you might as well do:
>
> self elements do: [:each | ....

Tim

It looks as though we are talking about different versions of Yaxo. The
version I have, which I got from SqueakMap just over a year ago, is called
Yaxo-2.0b. In this version there is no mention of entities; elements just is
an instance variable, though its accessor uses a sort of lazy
initialisation:

elements

elements ifNil: [elements := OrderedCollection new].

^elements

The coding of #elementsDoAndRecurse: uses a simple extension of the existing
#elementsDo: method; I didn't stop to think if there was any implicit double
testing of conditions. However, the coding of #elements above shows that the
instance variable can have a nil value.

It would be as well to check whether your version of Yaxo from Dolphin
Harbor is up to date. When I corresponded with Hwee Boon last year, he said
he had agreed with Steve Waring to merge my port with the existing version
on DH and post the result back there; it looks as though that may not have
happened.

Good luck!

Peter Kenny

Tim M

Re: How do I use YAXO or any XML lib to find nodes?

Is there any way you can post your 2.0b port? The version on Dolphin
harbour says:

Download: DolphinYAXO_5.1.2.zip (download may be redirected to mirror)

Release Date: 6 Nov 2002

Version: 5.1.2

More importantly - this is what may be included in the latest D6, as
STS uses it. It would be good to ensure that at least the newer version
can be loaded or if not, that the newer dolphin could include the
latest version.

Tim M

Re: How do I use YAXO or any XML lib to find nodes?

I had a quick look at Squeak and got as far as loading YAXO from Squeak
Map (I think - Squeak is just too wierd for me to get my head around)

But not sure where it put it? In a Package browser I can see a Category
XML with some sub-section called Parser that has similar classes in it.
But If I click on parser and do file out, does that give me the code I
would need?

But then how did Dolphin endup with BASE and DOM packages?

Can I then use STS to help me import this stuff (I noticed there was
code snippet for importing squeak stuff in your readme Peter).

Anyway - any pointers would be helpful.

Tim

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by Tim M

"TimM" <[hidden email]> wrote in message
news:[hidden email]...

> Is there any way you can post your 2.0b port? The version on Dolphin
> harbour says:
>
> Download: DolphinYAXO_5.1.2.zip (download may be redirected to mirror)
>
> Release Date: 6 Nov 2002
>
> Version: 5.1.2
>
> More importantly - this is what may be included in the latest D6, as
> STS uses it. It would be good to ensure that at least the newer version
> can be loaded or if not, that the newer dolphin could include the
> latest version.
>

Tim

My port is currently available on Bill Schwab's site
(http://needle.anest.ufl.edu/anest4/bills/Smalltalk.htm), but:
a. This is in a bundle which includes the Squeak HTML parsers (which
were my main interest).
b. There were one or two holes in the port (due to my ignorance of
Squeak syntax), which did not affect the HTML side but might be important
for XML.
I believe that Yar Hwee Boon produced a version of my port which filled in
the holes mentioned in b. above. My work has moved in a different direction
over the past year, so I am not currently working on this, but if anyone has
any queries not covered by the (rather long-winded) package comments I will
do my best to help.

Best wishes

Peter

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by Tim M

Tim

"TimM" <[hidden email]> wrote:

> I had a quick look at Squeak and got as far as loading YAXO from Squeak
> Map (I think - Squeak is just too wierd for me to get my head around)

I have looked at SqueakMap, and I am pretty certain that what is now there
is the same as I downloaded last year. So if you start there, you will
simply be repeating what I did. It will be easier to just import my package
SquealMapXMLParser.pac from Bill's site. As far as I can see, it is all
complete apart from a couple of methods in class XMLNamespaceScope, which
will only matter if you want to use namespaces - I am sure it will not be
too difficult to fix these anyway, once I understand the Squeak curly
bracket notation. I have checked back, and the ported code passed the YAXO
unit tests.

> (I noticed there was
> code snippet for importing squeak stuff in your readme Peter).
>

All that code snippet does is to convert the Squeak left-arrow assignment to
the Dolphin convention and change the line ending convention. This is
irrelevant if you start from my ported code .

Best wishes

Peter

hboon@motionobj.com

Re: How do I use YAXO or any XML lib to find nodes?

In reply to this post by Peter Kenny-2

Opps. I did have the intention to do the integration and had a short
discussion with Steve. I started working on it but interest faded as I
moved on to something else :) Sorry for not updating the status. I seem
to remember David Gorisek's OmniBase (or was it STS) packages come with
the YAXO package. Maybe someone can check it out and see if he allows
usage of it, if it is appropriate.

--
Hwee Boon

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

"[hidden email]" <[hidden email]> wrote:
> Opps. I did have the intention to do the integration and had a short
> discussion with Steve. I started working on it but interest faded as I
> moved on to something else :) Sorry for not updating the status.

Hwee Boon

Never mind - much the same happens to most of us, including me. But could
you remind me how you completed my port of YAXO by translating the Squeak
curly bracket notation? (It affects the methods
XMLNamespaceScope>>enterScope and >>initScope only, as far as I can see.) If
I had that, I could post the completed port on Bill's site, and that might
be helpful to Tim. If Tim is right, STS uses the older version of YAXO that
is on DolphinHarbor.

Thanks

Peter

hboon@motionobj.com

Re: How do I use YAXO or any XML lib to find nodes?

Offhand, these would be:

enterScope
self scope addLast: (Array with: self defaultNamespace with: nil with:
currentBindings)

initScope
scope := OrderedCollection new: 20.
currentBindings := Dictionary new.
scope addLast: (Array with: 'http://www.w3.org/TR/REC-xml-names' with:
currentBindings with: nil)

since the Squeak {} syntax is evaluated at run time (contrast with #())
to create an Array instance.

--
Hwee Boon

Peter Kenny-2

Re: How do I use YAXO or any XML lib to find nodes?

"[hidden email]" <[hidden email]> wrote in message
news:[hidden email]...

> Offhand, these would be:
>
> enterScope
> self scope addLast: (Array with: self defaultNamespace with: nil with:
> currentBindings)
>
>
> initScope
> scope := OrderedCollection new: 20.
> currentBindings := Dictionary new.
> scope addLast: (Array with: 'http://www.w3.org/TR/REC-xml-names' with:
> currentBindings with: nil)
>
>
> since the Squeak {} syntax is evaluated at run time (contrast with #())
> to create an Array instance.
>
> --
> Hwee Boon
>

Hwee Boon

Many thanks - I shall get those incorporated as soon as I can.

Peter

TimM-3

Re: How do I use YAXO or any XML lib to find nodes?

Guys - it would be good to push and get this stuff sorted out before the
release of D6 (and tested in that image), as YAXO does appear to be in the
D6 professional image due to STS.

While it seems that the differences are small - it has suprised me that
something quite common seems quite backward in such a modern environment...

But like you said - its often a labor of love and then you move on to
something else... I do wonder if Dolphin is missing a community repository
to pt these things into.... with STS being readily available maybe it would
be good to push for some open repository in both editions...

It seems to have helped squeak (if I could ever figure it out) a lot.

Tim

Anyway - I really appreciate your help and pointers.

"Peter Kenny" <[hidden email]> wrote in message
news:[hidden email]...

>
> "[hidden email]" <[hidden email]> wrote in message
> news:[hidden email]...
>> Offhand, these would be:
>>
>> enterScope
>> self scope addLast: (Array with: self defaultNamespace with: nil with:
>> currentBindings)
>>
>>
>> initScope
>> scope := OrderedCollection new: 20.
>> currentBindings := Dictionary new.
>> scope addLast: (Array with: 'http://www.w3.org/TR/REC-xml-names' with:
>> currentBindings with: nil)
>>
>>
>> since the Squeak {} syntax is evaluated at run time (contrast with #())
>> to create an Array instance.
>>
>> --
>> Hwee Boon
>>
>
> Hwee Boon
>
> Many thanks - I shall get those incorporated as soon as I can.
>
> Peter
>
>