Peter, OK, thanks for the concrete example. So these are out there in the wild, I'll add a special case to handle these. Thanks, Sven

On 05 Feb 2015, at 20:03, PBKResearch <peter@pbkresearch.co.uk> wrote:

Sven

I agree the '//' case is weird, I would never use it myself. However, my requirement is to be able to parse and dissect web pages, particularly Wikipedia and Wiktionary pages, and they use this construction all the time. Mostly it occurs in link tags in page headers. I think the reason is that the individual pages are in, for example, en.wiktionary.org, but shared resources are in bits.wikimedia.org; hence the 'relative' address is in effect a complete path (in which case why not put 'http:' in front and make it an absolute address?).

The problem arises in parsing with the Blanchard parser because it is designed as a validator, hence it follows up the links in the page header to make sure the resources exist. This is of no interest to me, I just want to get at the body of the page, but I carried on using it because it is very good at parsing the body. I had considered mutilating the parser by cutting out all the processing it does on link nodes. However, before that happened Monty pointed me to XMLHTMLParser and then Soup; these are just parsers, not validators, so as far as they are concerned the link addresses are just text.

As I said, I am pretty sure I shall abandon the Blanchard parser and use one of the two that Monty identified - probably Soup. Hence I can ignore this problem from now on. Whether you think '//' worth including is for you to decide. The only argument I can see is that it was handled by the now deprecated Url class, so in theory it could be used by someone still using Pharo 2 or earlier, who would find problems on updating to Pharo 3 or later.

Hope this helps

Peter Kenny

-----Original Message----- From: Sven Van Caekenberghe [mailto:sven@stfx.eu] Sent: 05 February 2015 17:28 To: PBKResearch Cc: monty; Pharo Development List Subject: Re: ZnUrl>>#withRelativeReference:

Peter,

Thanks for the feedback. (CC-ing the list)

...

On 05 Feb 2015, at 18:16, PBKResearch <peter@pbkresearch.co.uk> wrote:

Sven

Thanks for your efforts. I have tried ZnUrl>>#withRelativeReference: on the examples I gave in my e-mail of 11 Jan. Unfortunately it gives the same incorrect result as ZnUrl>>#inContextOf: in the case where the relative address begins with '//'. Admittedly this is a rather weird case, but RFC 3986 does acknowledge its existence (see para 4.2) and it is dealt with correctly by the old Url class>># combine:withRelative: (in fact there is special coding for this case in HierarchicalUrl>># privateInitializeFromText:). (I am not sure whether the pseudo-code in RFC 3986 sec 5 deals correctly with an initial '//'; it is not considered explicitly, but I could not follow all the ramifications of the case with initial '/'.)

I would like to understand why you need it, it seems very weird to me, it was one of the few cases that I decided not to implement:

In ZnUrlTests>>#testReferenceResolution

" '//g' -> 'http://g'. " "we do not support relative network path references (4.2)"

In the RFC they say (page 26)

<< A relative reference that begins with two slash characters is termed a network-path reference; such references are rarely used.

...

...

Could you please give a concrete example of how/why this is useful ?

Thx,

Sven

...

I feel rather guilty that you have gone to so much trouble because, thanks to Monty, I now have two alternatives to the Blanchard parser (XMLHTMLParser and Soup). I shall pretty certainly be using one or other of these in future, in place of the Blanchard parser, because they provide more flexible ways of interrogating the resulting DOM - and also because they are actively maintained. So from my point of view there is now no need for you to pursue this any further - unless you see this as a loose end to be tidied up.

Not problem, I am trying to make it right.

...

Thanks again

Peter Kenny

PS I can't post to the Pharo Development List, so I left that out of the addressee list.

-----Original Message----- From: Sven Van Caekenberghe [mailto:sven@stfx.eu] Sent: 05 February 2015 10:30 To: Pharo Development List Cc: monty; peter@pbkresearch.co.uk Subject: ZnUrl>>#withRelativeReference:

Hi,

I added ZnUrl>>#withRelativeReference: which implements the process described in section 5 of RFC 3986.

https://pharo.fogbugz.com/f/cases/14855/Add-reference-resolution-to-Zn Url

Summary:

In certain contexts (like links on a webpage) partial URLs are used that must be interpreted relative to a base URL (like the URL of the webpage itself).

Example:

'http://www.site.com/static/html/home.html' asZnUrl withRelativeReference: '../js/menu.js'

=> http://www.site.com/static/js/menu.js

This was previously not possible with ZnUrl.

If you know this stuff, please have a look.

Monty ? Peter ?

Sven

PS: this is in #bleedingEdge for now