tango object full names are not strict URIs

# 7 years ago
Carlos	Hi, I am reading the chapter C.2 of the tango manual (Tango object naming) and I see that the full name object names are "almost" URIs but not quite. This is an inconvenience for Taurus, which uses RFC3986-compliant URIs which are slightly different from the tango names According to the tango manual, the tango naming schema is: [protocol://][host:port/]device_name[/attribute][->property][#dbase=xx] The most problematic part (which is a common misunderstanding of URIs) is assuming that "://" is the separator between the protocol and the rest of the URI. According to RFC3986, the separator should be ":", and the "//" is a prefix that must be there if and only if the "authority" (i.e., [host:port]) is present in the name. In practice this means that `tango://freak:2345/id11/rv/1` is a valid URI, while `tango://id11/rv/1` is not a valid URI (it should be `tango:id11/rv/1`) Also, it means that `gizmo:20000/sr/d-ct/1` is not a valid URI because the host:port, when present, must be preceded by '//' even when the protocol is omitted,. Therefore, the valid URI would be: `//gizmo:20000/sr/d-ct/1` (note that, otherwise, if one wants to support arbitrary protocol names such as in taurus, `gizmo:20000/sr/d-ct/1` would be ambiguous because "gizmo" could be a protocol) Another problematic part (although not critical for taurus) is the use of "->" for the properties, since ">" is a reserved character in URIs. In summary, IMHO Tango should consider changing to (or at least simultaneously supporting) the following naming scheme: [protocol:][//host:port/]device_name[/attribute][->property][#dbase=xx] (or, if you want to be more strict, replace the "->" property separator by something else, for example ":") [protocol:][//host:port/]device_name[/attribute][:property][#dbase=xx] In terms of implementation, RFC3986 Appendix B provides a useful regexp to match proper URIs. Also, in Taurus4, we implemented regexp-based Tango URI validators which handle things such as device names given as device alias, etc. What do you think? Any chance of this being addressed for tango10? Cheers, Carlos

# 7 years ago

Hi,

I am reading the chapter C.2 of the tango manual (Tango object naming) and I see that the full name object names are "almost" URIs but not quite.

This is an inconvenience for Taurus, which uses RFC3986-compliant URIs which are slightly different from the tango names

According to the tango manual, the tango naming schema is:
[protocol://][host:port/]device_name[/attribute][->property][#dbase=xx]

The most problematic part (which is a common misunderstanding of URIs) is assuming that "://" is the separator between the protocol and the rest of the URI.

According to RFC3986, the separator should be ":", and the "//" is a prefix that must be there if and only if the "authority" (i.e., [host:port]) is present in the name.

In practice this means that
`tango://freak:2345/id11/rv/1`
is a valid URI, while
`tango://id11/rv/1`
is not a valid URI (it should be `tango:id11/rv/1`)

Also, it means that
`gizmo:20000/sr/d-ct/1`
is not a valid URI because the host:port, when present, must be preceded by '//' even when the protocol is omitted,. Therefore, the valid URI would be:
`//gizmo:20000/sr/d-ct/1`
(note that, otherwise, if one wants to support arbitrary protocol names such as in taurus, `gizmo:20000/sr/d-ct/1` would be ambiguous because "gizmo" could be a protocol)

Another problematic part (although not critical for taurus) is the use of "->" for the properties, since ">" is a reserved character in URIs.

In summary, IMHO Tango should consider changing to (or at least simultaneously supporting) the following naming scheme:

[protocol:][//host:port/]device_name[/attribute][->property][#dbase=xx]

(or, if you want to be more strict, replace the "->" property separator by something else, for example ":")

[protocol:][//host:port/]device_name[/attribute][:property][#dbase=xx]

In terms of implementation, RFC3986 Appendix B provides a useful regexp to match proper URIs. Also, in Taurus4, we implemented regexp-based Tango URI validators which handle things such as device names given as device alias, etc.

What do you think?
Any chance of this being addressed for tango10?

Cheers,

Carlos

# 7 years ago
Ingvord	Here is my 2-cents input: Would be nice if Tango uses REST API compatible URIs. Then using the same URIs structure the protocol may define the format of the response, e.g. tango: - binary format protocol specific for tango; http: - HTTP response etc Is it feasible?