Agree with Peter - but "screw things up" means then the users screws up.
Pharo and the Playground is working fine on them. But one has to know the
difference when
working with the Playground:
1. If you evaluate with an explicit variable declaration than the variable is
freshly defined and used like a temporary variable in a method:
| ingredientsXML |
ingredientsXML := XMLHTMLParser parseURL:
'https://ndb.nal.usda.gov/ndb/search/list?sort=ndb&ds=Standard+Reference'.
ingredientsXML inspect
You have to selected the full text and evaluate it (either with "do It" or
"print it" to get the result.
If you only select "ingredientsXML inspect" part first and evaluate then the
variable "ingredientsXML" is not known, undefined
and uninitialized and therefore results in a nil.
2. If in the playground you do not give an explicit variable declaration at
the beginning line like for example in
ingredientsXML := XMLHTMLParser parseURL:
'https://ndb.nal.usda.gov/ndb/search/list?sort=ndb&ds=Standard+Reference'.
ingredientsXML inspect
then a "workspace local variable" is implicitly created by the playground
as soon as you evaluate which means
- "ingredientsXML" is defined as a workspace variable as soon as you
evaluate
- the contents of "ingredientsXML" is preserved over different
evaluations within the workspace / playground
- you can use only "ingredientsXML" within this playground (not in
another plaground)
So you can evaluate the first line doing the assignment (this initializes
the workspace variable "ingredientsXML" for the current playground)
and when you later want to use it again you can just inspect it or evaluate
the second line in the same playground.
If you like you can open a second playground which can have its own
"ingredientsXML" workspace variable.
Workspace variables (or "playground variables") are convenient for
experimenting - as they are preserved - but
yes they might confuse you when you cant remember what was done with them last.
Bye
T.
> Gesendet: Dienstag, 07. Januar 2020 um 09:55 Uhr
> Von: "PBKResearch" <pe...@pbkresearch.co.uk>
> An: "'Any question about pharo is welcome'" <pharo-users@lists.pharo.org>
> Betreff: Re: [Pharo-users] [ANN] XMLParserHTML moved to GitHub
>
> It may be a quirk of how Pharo Playground works. It doesn't need local
> variable declarations - which is convenient - but putting them in can screw
> things up. Try your snippet again without the first line. Compare Torsten's
> code.
>
> HTH
>
> Peter Kenny
>
> -----Original Message-----
> From: Pharo-users <pharo-users-boun...@lists.pharo.org> On Behalf Of Torsten
> Bergmann
> Sent: 07 January 2020 07:47
> To: pharo-users@lists.pharo.org
> Cc: pharo-users@lists.pharo.org
> Subject: Re: [Pharo-users] [ANN] XMLParserHTML moved to GitHub
>
> Works without a problem (Pharo 8 on Windows), see attached. So it looks like
> a local problem.
>
> Just check the debugger and compare to the squeak version where you run in
> trouble.
> Maybe the document could not be retrieved on your machine.
>
> Bye
> T.
>
> > Gesendet: Dienstag, 07. Januar 2020 um 04:42 Uhr
> > Von: "LawsonEnglish" <lengli...@cox.net>
> > An: pharo-users@lists.pharo.org
> > Betreff: Re: [Pharo-users] [ANN] XMLParserHTML moved to GitHub
> >
> > Torsten Bergmann wrote
> > > Hi,
> > >
> > >
> > > You can load using
> > >
> > > Metacello new
> > > baseline: 'XMLParserHTML';
> > > repository: 'github://pharo-contributions/XML-XMLParserHTML/src';
> > > load.
> > >
> > >
> > > Bye
> > > T.
> >
> > Hi,
> >
> > I'm trying to use the sample code in the pharo screen scraping booklet
> > —
> > http://books.pharo.org/booklet-Scraping/pdf/2018-09-02-scrapingbook.pdf —
> > but while everything appears to load, I'm getting an odd behavior from:
> >
> > /| ingredientsXML |
> > ingredientsXML := XMLHTMLParser parseURL:
> > 'https://ndb.nal.usda.gov/ndb/search/list?sort=ndb&ds=Standard+Reference'.
> > ingredientsXML inspect/
> >
> > "#new was sent to nil"
> >
> > No matter what URL I use, I get the same message.
> >
> > I'm using Mac OS Catalina so I thought I might have some strange Mac
> > OS security issue (like it was quietly refusing to allow Pharo to
> > access the internet), but I tested with squeak and the old
> >
> > /html :=(HtmlParser parse:
> > 'https://ndb.nal.usda.gov/ndb/search/list?sort=ndb&ds=Standard+Reference'
> > asUrl retrieveContents content)/
> >
> > and that returns actual html without any problems.
> >
> >
> > Suggestions?
> >
> >
> > Thanks.
> >
> > L
> >
> >
> >
> >
> > --
> > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
> >
> >
>
>
>
