Updated dynamic path

utils/dynamicfieldpath.go

@@ -0,0 +1,91 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package utils
+
+import (
+	"strings"
+)
+
+// GetFullFieldPath returns the full path for the
+func GetFullFieldPath(fldPath string, dP DataProvider) (fpath *FullPath, err error) {
+	var newPath string
+	if newPath, err = processFieldPath(fldPath, dP); err != nil || newPath == EmptyString {
+		return
+	}
+	fpath = &FullPath{
+		PathItems: NewPathItems(strings.Split(newPath, NestingSep)),
+		Path:      newPath,
+	}
+
+	return
+}
+
+// replaces the dynamic path between <>
+func processFieldPath(fldPath string, dP DataProvider) (newPath string, err error) {
+	idx := strings.IndexByte(fldPath, RSRDynStartChar)
+	if idx == -1 {
+		return // no proccessing requred
+	}
+	newPath = fldPath[:idx] // add the first path of the path without the "<"
+	for idx != -1 {         // stop when we do not find any "<"
+		fldPath = fldPath[idx+1:]                                   // move the path to the begining of the index
+		nextBeginIdx := strings.IndexByte(fldPath, RSRDynStartChar) // get the next "<" if any
+		nextEndIdx := strings.IndexByte(fldPath, RSRDynEndChar)     // get the next ">" if any
+		if nextEndIdx == -1 {                                       // no end index found so return error
+			err = ErrWrongPath
+			newPath = EmptyString
+			return
+		}
+
+		// parse the rest of the field path until we match the [ ]
+		bIdx, eIdx := nextBeginIdx, nextEndIdx
+		for nextBeginIdx != -1 && nextBeginIdx < nextEndIdx { // do this until no new [ is found or the next begining [ is after the end ]
+			nextBeginIdx = strings.IndexByte(fldPath[bIdx+1:], RSRDynStartChar) // get the next "<" if any
+			nextEndIdx = strings.IndexByte(fldPath[eIdx+1:], RSRDynEndChar)     // get the next ">" if any
+			if nextEndIdx == -1 {                                               // no end index found so return error
+				err = ErrWrongPath
+				newPath = EmptyString
+				return
+			}
+			if nextBeginIdx == -1 { // if no index found do not increment but replace it
+				bIdx = -1
+			} else {
+				bIdx += nextBeginIdx + 1
+			}
+			// increment the indexes
+			eIdx += nextEndIdx + 1
+		}
+		var val string
+		for _, path := range strings.Split(fldPath[:eIdx], PipeSep) { // proccess the found path
+			if val, err = DPDynamicString(path, dP); err != nil {
+				newPath = EmptyString
+				return
+			}
+		}
+
+		if bIdx == -1 { // if is the last ocurence add the rest of the path and exit
+			newPath += val + fldPath[eIdx+1:]
+		} else {
+			// else just add until the next [
+			newPath += val + fldPath[eIdx+1:bIdx]
+		}
+		idx = bIdx
+	}
+	return
+}