Re: [j-nsp] understand "version" and "ns"(namespace) statements in SLAX scripts

[Phil Shafer]

Martin T writes:
>While I understand the idea of namespace in XML, then what is the
>point of those statements in SLAX scripts? In addition, how does the
>"version" statement work?

The version statement indicates the version of SLAX being used.  It
also confirms that the input is in fact a slax script.

There are currently three minor revisions of SLAX: 1.0, 1.1, and 1.2.
1.2 is completely backward compatible with 1.0 and 1.1, and 1.1 is
completely backward compatible with 1.0.

SLAX-1.1 adds all XSLT concepts directly to SLAX, where in 1.0 one
had to use the "xsl" namespace to access them (e.g. ),
as well as a debugger.  Details are in:

https://github.com/Juniper/libslax/wiki/NewIn1-1

I don't have as nice a write up for 1.2, but it adds two key things:
JSON-style data and data as arguments.  These allow code like:

var $x = {
"this": "that",
"one": 1
}
call my-template($rpc = );

There also a "main" statement that allows one to say:

main  {
call emit-my-output();
}

Note that the "--write-version" option to slaxproc can be used
to convert between versions:

% cat /tmp/foo.slax
version 1.2;

main  {
var $x = {
"this": "that",
"one": 1
}
call my-template($rpc = );
}
% slaxproc --format --write-version 1.0 /tmp/foo.slax
version 1.0;

match / {
 {
var $x = {
 "that";
 "1";
}
var $slax-temp-arg-1 = ;

call my-template($rpc = slax-ext:node-set($slax-temp-arg-1));
}
}

>ns junos = "http://xml.juniper.net/junos/*/junos;;
>ns xnm = "http://xml.juniper.net/xnm/1.1/xnm;;
>ns jcs = "http://xml.juniper.net/junos/commit-scripts/1.0;;
>ns ext = "http://xmlsoft.org/XSLT/namespace;;

The "ns" statement defines XML namespaces using the xmlns attribute.
The SLAX docs for it are here:

http://juniper.github.io/libslax/slax-manual.html#ns

and the XSLT docs are here:

http://www.w3.org/TR/xml-names11/#concepts

Note that the junos namespace is a bit "magic", in that when the
jcs:invoke and jcs:execute functions read data, they convert between
the version-specific namespace used by JUNOS into the "/*/" value
used above in the "ns junos" statement.  This removes the burden/pain
of namespaces and makes them much more useful.

Also in SLAX-1.2, namespaces are a bit simplified, so a script does
not need to explicitly name a namespace that implements extension
functions, since the extension function libraries will record their
information when they are installed.  For example, the "curl" and "bit"
namespaces (used to access libraries that ship with libslax) are automatically
discovered without the need for an explicit "ns" statement.  You
can see these discovered values using "slaxproc --format":

% cat /tmp/foo.slax
version 1.2;

main  {
expr bit:from-int(32, 10);
}
% slaxproc --format /tmp/foo.slax
version 1.2;

ns bit extension = "http://xml.libslax.org/bit;;

main  {
expr bit:from-int(32, 10);
}

The full docs for slax are available as part of the libslax
project on github:

   http://juniper.github.io/libslax/slax-manual.html

The "juise" project adds the juniper-specific libraries and a
program (called juise) that simplifies invoking op scripts
against a junos box.

Thanks,
 Phil
___
juniper-nsp mailing list juniper-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp

Re: [j-nsp] understand "version" and "ns"(namespace) statements in SLAX scripts

[Tom Storey]

According to libslax documentation, which is also the base of Junipers
implementation, the version statement indicates the minimum SLAX
language version required to run your script.

You can find libslax documentation here:
http://www.libslax.org/the-slax-language

On 22 December 2015 at 20:50, Martin T  wrote:
> Hi,
>
> if I look the SLAX script examples in Juniper web-site, then almost
> all of those examples have "version" and multiple "ns" statements. For
> example:
>
> version 1.0;
> ns junos = "http://xml.juniper.net/junos/*/junos;;
> ns xnm = "http://xml.juniper.net/xnm/1.1/xnm;;
> ns jcs = "http://xml.juniper.net/junos/commit-scripts/1.0;;
> ns ext = "http://xmlsoft.org/XSLT/namespace;;
>
>
> While I understand the idea of namespace in XML, then what is the
> point of those statements in SLAX scripts? In addition, how does the
> "version" statement work? Looks like this is (for some reason)
> mandatory as let's say that I have a following very simple script:
>
> $ cat hello_world.slax
> version 1.0;
>
> match / {
>{
>  "Hello World!";
>   }
> }
> $
>
> ..and I remove the "version 1.0;" line, then the script does not operate:
>
>> op hello_world
> error: /var/db/scripts/op/hello_world.slax:1: missing 'version'
> statement; 'match' is not legal
> error: /var/db/scripts/op/hello_world.slax: 1 error detected during parsing
> error: error reading stylesheet: hello_world.slax
>
>>
>
>
>
> thanks,
> Martin
> ___
> juniper-nsp mailing list juniper-nsp@puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp
___
juniper-nsp mailing list juniper-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp

[j-nsp] understand "version" and "ns"(namespace) statements in SLAX scripts

[Martin T]

Hi,

if I look the SLAX script examples in Juniper web-site, then almost
all of those examples have "version" and multiple "ns" statements. For
example:

version 1.0;
ns junos = "http://xml.juniper.net/junos/*/junos;;
ns xnm = "http://xml.juniper.net/xnm/1.1/xnm;;
ns jcs = "http://xml.juniper.net/junos/commit-scripts/1.0;;
ns ext = "http://xmlsoft.org/XSLT/namespace;;


While I understand the idea of namespace in XML, then what is the
point of those statements in SLAX scripts? In addition, how does the
"version" statement work? Looks like this is (for some reason)
mandatory as let's say that I have a following very simple script:

$ cat hello_world.slax
version 1.0;

match / {
   {
 "Hello World!";
  }
}
$

..and I remove the "version 1.0;" line, then the script does not operate:

> op hello_world
error: /var/db/scripts/op/hello_world.slax:1: missing 'version'
statement; 'match' is not legal
error: /var/db/scripts/op/hello_world.slax: 1 error detected during parsing
error: error reading stylesheet: hello_world.slax

>



thanks,
Martin
___
juniper-nsp mailing list juniper-nsp@puck.nether.net
https://puck.nether.net/mailman/listinfo/juniper-nsp