Add GetNextIndex method and enhance SetValueAt for array handling; update tests for new functionality

Author: grongierisc

src/iop/cls/IOP/Message.cls

@@ -1,4 +1,4 @@
-Class IOP.Message Extends (Ens.MessageBody, %CSP.Page, %XML.Adaptor, Ens.VDoc.Interface)
+Class IOP.Message Extends (Ens.MessageBody, %CSP.Page, Ens.VDoc.Interface)
 {
 
 Parameter DOCCLASSNAME = "JSON Document";
@@ -27,6 +27,19 @@ Property jstr As %Stream.GlobalCharacter [ Internal, Private ];
 
 Property type As %String(MAXLEN = 6) [ ReadOnly ];
 
+/// Gets the next index in an array
+Method GetNextIndex(
+	pPath As %String,
+	pIndex As %String,
+	ByRef pStatus As %Status = {$$$OK}) As %String
+{
+    Set f=$F(pPath,"()")  If 'f Set pStatus=$$$ERROR($$$EnsErrGeneral,"Can't iterate on no-array type '"_pPath_"'") Quit ""
+    if pIndex="" Set pIndex=1
+    Set tValue = ..GetValueAt($EXTRACT(pPath, 1, $LENGTH(pPath)-2))
+    if pIndex>$LENGTH(tValue) Quit ""
+    Quit pIndex+1
+}
+
 Method GetValueAt(
 	pPropertyPath As %String = "",
 	pFormat As %String,
@@ -152,13 +165,20 @@ Method SetValueAt(
     Set tSC = $$$OK
     // if pAction is set, use jsonpath to set the value
     Try {
+        if pAction = "append" {
+            // trinm () from the end of the path
+            if $EXTRACT(pPropertyPath, *) = ")" {
+                Set pPropertyPath = $EXTRACT(pPropertyPath, 1, $LENGTH(pPropertyPath)-2)
+            }
+        }
         // Convert pPropertyPath to a a jsonpath
         Set tPath = ..ConvertPath(pPropertyPath)
 
         Set pyjson = ##class(%SYS.Python).Import("json")
         Set jp = ##class(%SYS.Python).Import("jsonpath_ng")
         Set builtins = ##class(%SYS.Python).Builtins()
 
+        // By default, if json is empty, set it to an empty object
         if ..json = "" {
             Set ..json = "{}"
         }
@@ -168,6 +188,18 @@ Method SetValueAt(
         if pAction = "set" {
             Set tJSON = parser."update_or_create"(tJSON, pValue)
         }
+        ElseIf pAction = "append" {
+            Set tFindValue = parser."find"(tJSON)
+            if tFindValue."__len__"() = 0 {
+                Set tList = builtins.list()
+                Do tList.append(pValue)
+                Set tJSON = parser."update_or_create"(tJSON,tList)
+            }
+            Else {
+                Do tFindValue."__getitem__"(0)."value".append(pValue)
+                Set tJSON = parser."update"(tJSON, tFindValue."__getitem__"(0)."value")
+            }
+        }
 
         Set tResult = pyjson.dumps(tJSON)
         Set ..json = tResult

src/tests/test_iop_dtl.py

@@ -41,12 +41,15 @@ def test_get_value_at(iop_message, json_data, path, expected):
 
 @pytest.mark.parametrize("json_data,path,value,action,key,expected_json", [
     ('{"string":"Foo", "integer":42}', 'string', 'Bar', 'set', None, '{"string":"Bar", "integer":42}'),
-    (r'{"post":{"Title":"Foo"}}', 'post.Title', 'Bar', 'set', None, r'{"post":{"Title":"Bar"}}')
+    (r'{"post":{"Title":"Foo"}}', 'post.Title', 'Bar', 'set', None, r'{"post":{"Title":"Bar"}}'),
+    (r'{}', 'post.Title', 'Bar', 'set', None, r'{"post":{"Title":"Bar"}}'),
+    (r'{}', 'post()', 'Bar', 'append', None, r'{"post":["Bar"]}'),
+    (r'{"post":["Foo"]}', 'post()', 'Bar', 'append', None, r'{"post":["Foo","Bar"]}'),
 ])
 def test_set_value_at(iop_message, json_data, path, value, action, key, expected_json):
     iop_message.json = json_data
     iop_message.classname = 'foo'
-    iop_message.SetValueAt(value, path, action, key)
+    _Utils.raise_on_error(iop_message.SetValueAt(value, path, action, key))
     assert json.loads(iop_message.json) == json.loads(expected_json)
 
 @pytest.mark.parametrize("json_data,classname,transform_class,expected_value", [