Implement config reading functions and a minimal command line client for using them.

Yes, I hate oversized commits too, but this is hard to avoid sometimes.

Adjustments to the Session functions logic required to make it work:
 Do not try to validate the path. The validation function is geared towards
  validating _set_ paths, so when path lacks a value, it doesn't work right.
  We assume that the path has been through set at some point, so if a path
  currently exists in the config tree, it is also a valid path that can be used for
  Reference_tree.is_leaf etc.

1 files changed, 31 insertions, 17 deletions

diff --git a/src/session.ml b/src/session.ml
index 90ab5c8..a502629 100644
--- a/src/session.ml
+++ b/src/session.ml
@@ -77,27 +77,41 @@ let delete w s path =
     {s with proposed_config=config; changeset=(op :: s.changeset)}
 
 let get_value w s path =
-    let path, _ = RT.validate_path D.(w.dirs.validators) w.reference_tree path in
-    if RT.is_leaf w.reference_tree path then
-        if not ((RT.is_multi w.reference_tree path) || (RT.is_valueless w.reference_tree path))
-        then CT.get_value s.proposed_config path
-        else raise (Session_error "This node can have more than one value")
-    else raise (Session_error "Cannot get a value of a non-leaf node")
+    if not (Vytree.exists s.proposed_config path) then
+        raise (Session_error ("Path does not exist"))
+    else if not (RT.is_leaf w.reference_tree path) then
+        raise (Session_error "Cannot get a value of a non-leaf node")
+    else if (RT.is_multi w.reference_tree path) then
+        raise (Session_error "This node can have more than one value")
+    else if (RT.is_valueless w.reference_tree path) then
+        raise (Session_error "This node can have more than one value")
+    else CT.get_value s.proposed_config path
 
 let get_values w s path =
-    let path, _ = RT.validate_path D.(w.dirs.validators) w.reference_tree path in
-    if RT.is_leaf w.reference_tree path then
-        if RT.is_multi w.reference_tree path
-        then CT.get_values s.proposed_config path
-        else raise (Session_error "This node can have only one value")
-    else raise (Session_error "Cannot get a value of a non-leaf node")
+    if not (Vytree.exists s.proposed_config path) then
+        raise (Session_error ("Path does not exist"))
+    else if not (RT.is_leaf w.reference_tree path) then
+        raise (Session_error "Cannot get a value of a non-leaf node")
+    else if not (RT.is_multi w.reference_tree path) then
+        raise (Session_error "This node can have only one value")
+    else  CT.get_values s.proposed_config path
 
 let list_children w s path =
-    let path, _ = RT.validate_path D.(w.dirs.validators) w.reference_tree path in
-    if not (RT.is_leaf w.reference_tree path)
-    then Vytree.children_of_path s.proposed_config path
-    else raise (Session_error "Cannot list children of a leaf node")
+    if not (Vytree.exists s.proposed_config path) then
+        raise (Session_error ("Path does not exist"))
+    else if (RT.is_leaf w.reference_tree path) then
+        raise (Session_error "Cannot list children of a leaf node")
+    else Vytree.children_of_path s.proposed_config path
 
 let exists w s path =
-    let path, _ = RT.validate_path D.(w.dirs.validators) w.reference_tree path in
     Vytree.exists s.proposed_config path
+
+let show_config w s path fmt =
+    let open Vyconf_types in
+    if not (Vytree.exists s.proposed_config path) then
+        raise (Session_error ("Path does not exist")) 
+    else
+        let node = Vytree.get s.proposed_config path in
+        match fmt with
+        | Curly -> CT.render node
+        | Json -> CT.to_yojson node |> Yojson.Safe.pretty_to_string