Retrieving all nodes: ly_ctx_get_node() vs. lyd_get_node()

[milanlenco]

Some time ago we were discussing that in order to get all the nodes of a module, the xpath /test-module:*//. should be used rather than /test-module:*//*.
But after we replaced * with . in our test applications, we started to observe the following error:
libyang: Unexpected character(s) '*' (*//.).
It turned out that while lyd_get_node() processes this xpath just fine, ly_ctx_get_node() returns this error. Is there a difference between these two functions related to the input xpath that we should be aware of?

Thanks,
Milan

[michalvasko]

Hi Milan,
if you read the function documentation carefully, you will notice that ly_ctx_get_node() accepts "schema node identifier in JSON format", while ld_get_node() an "XPath expression". The difference is explained in more detail in the general documentation, which is available if you execute make doc. Look into the HTML documentation libyang/How To.../XPath Addressing. Very briefly, the reason for the difference is that ly_ctx_get_node() is evaluated on schema.

Regards,
Michal