ZnClient and percent characters

Norbert

Am 11.06.2015 um 16:51 schrieb PBKResearch <[hidden email]>:

 

Norbert

 

Apology accepted – I had never heard this term before. However, having read the Wikipedia article Henry mentioned, I do not think it applies to what I had done. If Sven accepts the argument that commas should always be encoded in query lines – and I can see a strong argument for that from what I have read – then the change I made is just what he will need to do. I simply anticipated the decision. If it goes the other way, then it was just a hack to solve Jimmie’s problem – but it might be better to say ‘hack’ rather than use a term which is potentially offensive.

 

I just wrote because you told Jimmie to alter a method of a third-party library. And that is a no-go. The way to change it and have Sven it commited is doable. As is my proposal that you can change the code in a reliable way without changing a third-party library. That's all I wanted to say. And yes I think it applies to monkey patching. Choosing weaker terms just to avoid problems is not the way to go IMHO. 

I also note Jimmie’s argument that, as long as there are some sites which insist on encoded commas, it must be possible to generate such lines if Zinc is to be generally useful. Whether this should be a user-controlled option, as Sven seems to suggest, is open to discussion – but if so I would argue for encoding of commas as the safe default, which can be overridden if necessary.

 

Sure. Zinc should behave correctly and it should provide functionalities to make it "less correct". And these functionalities shouldn't be too easy to use ;)

Norbert

Peter Kenny

 

From: Pharo-users [[hidden email]] On Behalf Of Norbert Hartl
Sent: 11 June 2015 11:25
To: Pharo users users
Subject: Re: [Pharo-users] ZnClient and percent characters

 

No offense meant. I assumed you would know the term. Sorry! Henry explained it quite good what I meant.

 

Norbert

 

Am 11.06.2015 um 09:51 schrieb PBKResearch <[hidden email]>:

 

I don’t quite understand Norbert’s comment. Does ‘monkey’ apply to me or to what I have done? Either way, it seems unnecessary and abusive. 

 

Thanks to Sven’s careful use of informative method names, the effect of my change is quite clear. Any comma in the value part of a query line will be encoded. Nothing else. I did my best to trace any side effects, and didn’t find any. What is not ‘reliable’ about that?

 

Peter Kenny

 

 

I was thinking of a reliable solution. Of course if it only needs to be tested than monkey patching foreign packages is ok. 

 

Norbert

 

Am 11.06.2015 um 01:22 schrieb PBKResearch <[hidden email]>:

 

There is a simpler way than Norbert’s suggestion. Find the class ZnResourceMetaUtils (in the package Zinc-Resource-Meta-Core). Locate the class side method #queryKeyValueSafeSet. Remove the comma from the string. With this change your ‘Google’ example generates the query line with the ‘%2C’ encoding of the commas.

 

Of course, with this change a comma in the value field of a query will always be encoded. It is not clear to me whether this is correcting an error in Zinc, or just a hack to solve your problem – earlier posts here endorse both views. No doubt Sven is the person to sort this out. Meanwhile, this will enable you to get moving.

 

Hope this helps

 

Peter Kenny

 

From: Pharo-users [[hidden email]] On Behalf Of Norbert Hartl
Sent: 10 June 2015 23:56
To: Pharo users users
Subject: Re: [Pharo-users] ZnClient and percent characters

 

Just to clarify:

 

"Characters in the "reserved" set are not reserved in all contexts.

   The set of characters actually reserved within any given URI

   component is defined by that component. In general, a character is

   reserved if the semantics of the URI changes if the character is

   replaced with its escaped US-ASCII encoding."

If I were you I'd subclass ZnUrl and implement 

#encodeQuery:on:

on that class. You could have an extension method in ZnResourceMetaUtils that returns the character set you need to have encoded. In ZnClient you just set your ZnUrl derived class object as #url:

Cannot think of anything better for a quick resolve of your problem.

Norbert

Am 11.06.2015 um 00:26 schrieb Jimmie Houchin <[hidden email]>:

 

I am not an expert on URIs or encoding. However, this is a requirement of the API I am using and I am required to submit an encoded URI with %2C and no commas.

As far as commas needing to be escaped, it seems from other sources that they should be.

From https://www.ietf.org/rfc/rfc2396.txt

The plus "+", dollar "$", and comma "," characters have been added to

   those in the "reserved" set, since they are treated as reserved

   within the query component.

States that commas are reserved within the query component.

http://stackoverflow.com/questions/8828702/why-is-the-comma-url-encoded

Regardless of what is or is not required, I do need the ability to have a query string with commas encoded as %2C in order to satisfy and use the API which states.

fields: Optional An URL encoded (%2C) comma separated list of instrument fields that are to be returned in the response. The instrument field will be returned regardless of the input to this query parameter. Please see the Response Parameters section below for a list of valid values.

Which will look like this or something similar.

fields=displayName%2Cinstrument%2Cpip

Thanks.

Jimmie

On 06/10/2015 03:27 PM, Norbert Hartl wrote:

That's because the comma does not need to be escaped in the query part of the uri.

Norbert

Am 10.06.2015 um 22:00 schrieb Jimmie Houchin [hidden email]:

On 06/10/2015 10:32 AM, Sven Van Caekenberghe wrote:

On 10 Jun 2015, at 17:24, David [hidden email] wrote:

El Wed, 10 Jun 2015 10:14:37 -0500

Jimmie Houchin [hidden email]

escribió:

Hello,

I am attempting to use ZnClient to request data. The request requires

a %2C (comma) delimited string as part of the query. Below is a

snippet.

znClient

        addPath: '/v1/instruments';

        queryAt: 'fields' putAll: 'displayName%2Cinstrument%2Cpip';

        get ;

        contents)

The string  'displayName%2Cinstrument%2Cpip'

is being converted to  'displayName%252Cinstrument%252Cpip'

which causes the request to fail.

The query needs to be

fields=displayName%2Cinstrument%2Cpip

I have not found how to do this correctly.

Any help greatly appreciated.

Thanks.

Jimmie

Maybe a silly thing, but since %2C = , ... Did you tried already to

make itself encode that? Like

znClient

         addPath: '/v1/instruments';

         queryAt: 'fields' putAll: 'displayName,instrument,pip';

         get ;

         contents)

I suspect it is using encoding internally, that is why % is also

encoded if you try to put it.

I hope that works

Not silly and no need to suspect, but absolutely correct !

Sven

My apologies for not having full disclosure.

Pharo 4, new image, freshly installed Zinc stable version.

Xubuntu 15.04

That is what I thought would happen and what I tried first. But it is not being encoded from what I can find.

Inspect this in a workspace/playground.

ZnClient new

       https;

       host: 'google.com';

       addPath: '/commaTest';

       queryAt: 'fields' put: 'displayName,instrument,pip';

       yourself

View the  request / requestLine / uri.  The commas are still present in the URI.

So I tried encoding myself and get the other error.

Of course Google won't understand this and in this snippet won't receive it.

And please let me know if I am doing something wrong.

Any help greatly appreciated.

Jimmie

Am 12.06.2015 um 12:03 schrieb PBKResearch <[hidden email]>:

 

Norbert

 

Some comments on your latest post below.

 

I just wrote because you told Jimmie to alter a method of a third-party library. And that is a no-go.

 

Zinc, like almost all of Pharo, is MIT licenced, “including without limitation the rights to use, copy, modify, merge, publish…” Once the code is on my machine, I am entitled to alter it for my own use in any way I see fit; so is Jimmie. It is clear from Sven’s comments that not encoding commas is a design decision, and a departure from earlier Zinc working. Sven himself says “ maybe we made a mistake, maybe not.” I am entitled to disagree with that decision, and to act on that disagreement; so is Jimmie. I just told him how to do it quickly and safely.

 

So, the misunderstanding is because we seem to have different views on the topic. I have always projects in mind that are built together by a build system and they produce something deployable. Your proposal doesn't fit in this view for me. If you alter a third-party function you need to make that a repeatable task which is having an expression to patch the third-party library again if you build the project again. 

The way to change it and have Sven it commited is doable. 

 

Obviously it would be ideal if Sven made a change which allowed encoding of commas. However, that does not seem likely to happen any time soon. Meanwhile, Jimmie was stuck with a program which would not carry out a function that should be quite normal.

 

As is my proposal that you can change the code in a reliable way without changing a third-party library. That's all I wanted to say. 

 

No doubt your subclassing approach would work, though not as easily as you imply. The method that encodes the key-value pairs of a query is not #encodeQuery:on:, it is #printQueryOn: (see ZnUrl>>#printPathQueryFragmentOn:); changing that would involve having variant versions of ZnResourceMetaUtils>>#writeQueryFields:on: and >>writeQueryFields:withEncoder:on:, as well as a new safe list.

Yes, but it is still the thing you can do immediately without having to patch code that is not under your control. That's my whole point. I wouldn't consider my approach good or even nice. 

 

And yes I think it applies to monkey patching. Choosing weaker terms just to avoid problems is not the way to go IMHO.

 

I was not asking for a weaker term, I was asking for a less offensive one. I think this term is offensive in all contexts, and should not be used. Henry’s comment implies that it is widely used, and everyone knows what it means. In my youth, 60-70 years ago, the n-word was widely used to refer to people of African origin, and everyone knew what it meant. Now, thank goodness, we see how offensive it was. To me, this expression is equally offensive. You used it, in a derogatory sense, to criticise what I had done in helping Jimmie. Frankly, I do not think you were sincere in saying “No offense meant.”

 

I like the term monkey patching because it is as funny as it might be offensive. The rest I don't want to comment because I could easily be offended by your paragraph above…if I only had those kinds of sensitivities. And btw. don't hide behind something like not using a certain word. You can still be a racist without using the n-word. What is needed is to change attitude not words. 

I had thought of just ignoring your comment, thinking that we will have to agree to differ. However, your reiteration of the m-word has got me sufficiently riled to make another protest. I may be a lone voice here, but that does not make my views any less valid.

dito.

Let's close this case. To me it is a little misunderstanding that took the wrong route.

Norbert

 

Peter Kenny

 

 

From: Pharo-users [[hidden email]] On Behalf Of Norbert Hartl
Sent: 11 June 2015 17:07
To: Pharo users users
Subject: Re: [Pharo-users] ZnClient and percent characters

 

 

Am 11.06.2015 um 16:51 schrieb PBKResearch <[hidden email]>:

 

Norbert

 

Apology accepted – I had never heard this term before. However, having read the Wikipedia article Henry mentioned, I do not think it applies to what I had done. If Sven accepts the argument that commas should always be encoded in query lines – and I can see a strong argument for that from what I have read – then the change I made is just what he will need to do. I simply anticipated the decision. If it goes the other way, then it was just a hack to solve Jimmie’s problem – but it might be better to say ‘hack’ rather than use a term which is potentially offensive.

 

I just wrote because you told Jimmie to alter a method of a third-party library. And that is a no-go. The way to change it and have Sven it commited is doable. As is my proposal that you can change the code in a reliable way without changing a third-party library. That's all I wanted to say. And yes I think it applies to monkey patching. Choosing weaker terms just to avoid problems is not the way to go IMHO. 

I also note Jimmie’s argument that, as long as there are some sites which insist on encoded commas, it must be possible to generate such lines if Zinc is to be generally useful. Whether this should be a user-controlled option, as Sven seems to suggest, is open to discussion – but if so I would argue for encoding of commas as the safe default, which can be overridden if necessary.

 

Sure. Zinc should behave correctly and it should provide functionalities to make it "less correct". And these functionalities shouldn't be too easy to use ;)

 

Norbert

Peter Kenny

 

From: Pharo-users [[hidden email]] On Behalf Of Norbert Hartl
Sent: 11 June 2015 11:25
To: Pharo users users
Subject: Re: [Pharo-users] ZnClient and percent characters

 

No offense meant. I assumed you would know the term. Sorry! Henry explained it quite good what I meant.

 

Norbert

 

Am 11.06.2015 um 09:51 schrieb PBKResearch <[hidden email]>:

 

I don’t quite understand Norbert’s comment. Does ‘monkey’ apply to me or to what I have done? Either way, it seems unnecessary and abusive. 

 

Thanks to Sven’s careful use of informative method names, the effect of my change is quite clear. Any comma in the value part of a query line will be encoded. Nothing else. I did my best to trace any side effects, and didn’t find any. What is not ‘reliable’ about that?

 

Peter Kenny

 

 

I was thinking of a reliable solution. Of course if it only needs to be tested than monkey patching foreign packages is ok. 

 

Norbert

 

Am 11.06.2015 um 01:22 schrieb PBKResearch <[hidden email]>:

 

There is a simpler way than Norbert’s suggestion. Find the class ZnResourceMetaUtils (in the package Zinc-Resource-Meta-Core). Locate the class side method #queryKeyValueSafeSet. Remove the comma from the string. With this change your ‘Google’ example generates the query line with the ‘%2C’ encoding of the commas.

 

Of course, with this change a comma in the value field of a query will always be encoded. It is not clear to me whether this is correcting an error in Zinc, or just a hack to solve your problem – earlier posts here endorse both views. No doubt Sven is the person to sort this out. Meanwhile, this will enable you to get moving.

 

Hope this helps

 

Peter Kenny

 

From: Pharo-users [[hidden email]] On Behalf Of Norbert Hartl
Sent: 10 June 2015 23:56
To: Pharo users users
Subject: Re: [Pharo-users] ZnClient and percent characters

 

Just to clarify:

 

"Characters in the "reserved" set are not reserved in all contexts.

   The set of characters actually reserved within any given URI

   component is defined by that component. In general, a character is

   reserved if the semantics of the URI changes if the character is

   replaced with its escaped US-ASCII encoding."

If I were you I'd subclass ZnUrl and implement 

#encodeQuery:on:

on that class. You could have an extension method in ZnResourceMetaUtils that returns the character set you need to have encoded. In ZnClient you just set your ZnUrl derived class object as #url:

Cannot think of anything better for a quick resolve of your problem.

Norbert

Am 11.06.2015 um 00:26 schrieb Jimmie Houchin <[hidden email]>:

 

I am not an expert on URIs or encoding. However, this is a requirement of the API I am using and I am required to submit an encoded URI with %2C and no commas.

As far as commas needing to be escaped, it seems from other sources that they should be.

From https://www.ietf.org/rfc/rfc2396.txt

The plus "+", dollar "$", and comma "," characters have been added to

   those in the "reserved" set, since they are treated as reserved

   within the query component.

States that commas are reserved within the query component.

http://stackoverflow.com/questions/8828702/why-is-the-comma-url-encoded

Regardless of what is or is not required, I do need the ability to have a query string with commas encoded as %2C in order to satisfy and use the API which states.

fields: Optional An URL encoded (%2C) comma separated list of instrument fields that are to be returned in the response. The instrument field will be returned regardless of the input to this query parameter. Please see the Response Parameters section below for a list of valid values.

Which will look like this or something similar.

fields=displayName%2Cinstrument%2Cpip

Thanks.

Jimmie

On 06/10/2015 03:27 PM, Norbert Hartl wrote:

That's because the comma does not need to be escaped in the query part of the uri.

Norbert

Am 10.06.2015 um 22:00 schrieb Jimmie Houchin [hidden email]:

On 06/10/2015 10:32 AM, Sven Van Caekenberghe wrote:

On 10 Jun 2015, at 17:24, David [hidden email] wrote:

El Wed, 10 Jun 2015 10:14:37 -0500

Jimmie Houchin [hidden email]

escribió:

Hello,

I am attempting to use ZnClient to request data. The request requires

a %2C (comma) delimited string as part of the query. Below is a

snippet.

znClient

        addPath: '/v1/instruments';

        queryAt: 'fields' putAll: 'displayName%2Cinstrument%2Cpip';

        get ;

        contents)

The string  'displayName%2Cinstrument%2Cpip'

is being converted to  'displayName%252Cinstrument%252Cpip'

which causes the request to fail.

The query needs to be

fields=displayName%2Cinstrument%2Cpip

I have not found how to do this correctly.

Any help greatly appreciated.

Thanks.

Jimmie

Maybe a silly thing, but since %2C = , ... Did you tried already to

make itself encode that? Like

znClient

         addPath: '/v1/instruments';

         queryAt: 'fields' putAll: 'displayName,instrument,pip';

         get ;

         contents)

I suspect it is using encoding internally, that is why % is also

encoded if you try to put it.

I hope that works

Not silly and no need to suspect, but absolutely correct !

Sven

My apologies for not having full disclosure.

Pharo 4, new image, freshly installed Zinc stable version.

Xubuntu 15.04

That is what I thought would happen and what I tried first. But it is not being encoded from what I can find.

Inspect this in a workspace/playground.

ZnClient new

       https;

       host: 'google.com';

       addPath: '/commaTest';

       queryAt: 'fields' put: 'displayName,instrument,pip';

       yourself

View the  request / requestLine / uri.  The commas are still present in the URI.

So I tried encoding myself and get the other error.

Of course Google won't understand this and in this snippet won't receive it.

And please let me know if I am doing something wrong.

Any help greatly appreciated.

Jimmie