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rudimentary file parser with mgWalk?
Hi Chris,
Yeah, you had a reply on the forum that mentioned that so I was able to get a little further.
Can you explain how you move up and down the tree? So if I go all the way down the left side, how do I go 'back up' to go down any other branch??
Thanks!
OK, thanks. I'll give that a go.
I'm working on a way to prune everything in a db that is not part of a switch tree. I need to keep the db root, obviously.
I'm thinking of traversing the db once, identify nodes that are not children of switches, remove them.
Then walk the db again, and if there are no children, delete that node. This would have to happen recursively, I think.
That can't be the best way to do this, right? What's a better way?
Thx
This feels pretty kludgy, but it also almost works. If a node meets certain criteria, it gets added to the keepList. I would like to put nodes not in keepList into a pruneList, but my attempts to do that in-line don't work. I may need another pass through the database, then I can check against keepList and if not in there, add to pruneList.
groupCode = 309
rootCode = 310
lodCode = 324
switchCode = 362
code = mgGetCode (rec)
name = mgGetName (rec)
parent = mgGetParent (rec)
parentName = mgGetName (parent)
parentCode = mgGetCode (parent)
no_switches_found = 0
codeSupported = MG_TRUE
checkTransforms = MG_TRUE
# print node name and type
# PrintNodeNameAndCode (rec)
if code == fltSwitch:
print ('======================')
print ('parent:',parentName)
if not parentName in keepList:
keepList.append(parentName)
if not name in keepList:
keepList.append(name)
# print ('mgDelete (rec)')
elif code == fltObject:
if not parentCode == switchCode:
print ('=================')
print ('parent:',parentName)
# print (mgGetCode(parent))
print ('found object',name)
else:
if not parentName in keepList:
pruneList.append(name)
# mgDelete (rec)
elif code == fltGroup:
if parentCode == rootCode:
print ('checking root:', name)
if not name in keepList:
keepList.append(name)
elif not parentCode == switchCode:
print ('=================')
#print ('group code:',mgGetCode(rec))
print ('parent:',parentName)
print ('parent code:',parentCode)
print ('found group',name)
if parentName in keepList:
numChildNodes = mgCountChild(rec)
if numChildNodes == 1:
if mgGetCode(mgGetChild(rec)) == groupCode or mgGetCode(mgGetChild(rec)) == lodCode:
if not name in keepList:
keepList.append(name)
else:
for i in range(1,numChildNodes):
childnth = mgGetChildNth(rec,i)
if not mgGetCode(childnth) == switchCode:
print ('-------------- no switches found!')
no_switches_found = 1
elif parentName in keepList:
if not name in keepList:
if not no_switches_found == 1:
keepList.append(name)
# if we aren't keeping the node then add to prune
else:
if not parentName in keepList or parentCode == lodCode:
pruneList.append(name)
# mgDelete (rec)
elif code == fltLod:
print ('parent:',parentName,'LOD code:',mgGetCode(rec))
numChildNodes = mgCountChild(rec)
print ('keeping:',keepList)
if parentCode == lodCode:
if not name in keepList:
keepList.append(name)
elif numChildNodes > 0:
for i in range(1,numChildNodes):
childnth = mgGetChildNth(rec,i)
print ('child:',mgGetName(childnth))
if mgGetCode(childnth) == switchCode or mgGetName(childnth) in keepList:
if not name in keepList:
keepList.append(name)
else:
no_switches_found = 1
if parentName in keepList:
if not no_switches_found == 1:
if not name in keepList:
keepList.append(name)
print ('found LOD',name)
print ('=================')Here's what I get - I think it's accurate, but this is a simple file:
== keep these nodes ==
res_90
g160
LOD_top
details
signs
s_env_pkdVeh_res_90_0x_0y_0r
s_env_garage_res_90_0x_0y_0r
s_spdLmt_r1b_res_90_0x_0y_0r
s_spdLmt_r1a_res_90_0x_0y_0r
Huh. A significantly more complex file doesn't work much :(
It keeps all the switches but not the hierarchy as intended.
Hey Shawn, sorry, I thought I replied yesterday but don't see my msg.
I threw something together and tested it on a moderately complex file.
- walk to get all the switch nodes into a list. This is used later
- Then walk again with a post and a pre func.
- In the pre func, you just keep track of how many switch nodes are above you in the walk
- In the post func you check to see if you are under a switch. If so you can't delete
- Then you check to see if you are above a switch. If so you can't delete.
- Knowing if you are above a switch is the hard part as walking down a tree is complicated. That is where the switch list comes in. It is easy to walk up a tree as everything narrows rather than widens. Basically you just walk up the tree of each switch node in the list. If any of them are a child of the node you are testing, you will find the node while iterating though parents.
Here is the code:
db = mgGetCurrentDb()
def gatherSwitchNodes (db, parent, rec, switchList):
if mgGetCode (rec) == fltSwitch:
switchList.append(rec)
return MG_TRUE
switchList = []
mgWalk(db, gatherSwitchNodes, None, switchList, MWALK_NOREADONLY)
def isNodeParent (parentNode, testChildren):
for possibleChild in testChildren:
testNode = possibleChild
while testNode and testNode != db:
if testNode == parentNode:
return MG_TRUE
testNode = mgGetParent(testNode)
return MG_FALSE
switchDepth = 0
def checkSwitch (db, parent, rec, data):
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth + 1
return MG_TRUE
def deleteNonSwitchNodes (db, parent, rec, deleteList):
global switchList
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth -1
# Switch depth tells us if we are under a switch
# Still need to see if we have a switch as a child
elif mgGetCode(rec) == fltGroup:
if switchDepth < 1 and not isNodeParent(rec, switchList) and not rec == db:
deleteList.append(rec)
return MG_TRUE
deleteList = []
mgWalk (db, checkSwitch, deleteNonSwitchNodes, deleteList, MWALK_NOREADONLY)
print len (deleteList)
for d in deleteList:
Awesome, thanks! This almost works. I'm looking at the left side of the tree and there's an object that isn't in the deleteList. Maybe object codes are not supported in this version (I see others that should be OK to delete, I will upload the file)?
Here's my version:
from mgapilib import *
import sys
mgInit (None, None)
print("\nOpening database: ",sys.argv[1],"\n")
db = mgOpenDb (sys.argv[1])
if db == None:
print(mgGetLastError (), "\n")
mgExit ()
# db = mgGetCurrentDb()
def gatherSwitchNodes (db, parent, rec, switchList):
if mgGetCode (rec) == fltSwitch:
switchList.append(rec)
return MG_TRUE
switchList = []
mgWalk(db, gatherSwitchNodes, None, switchList, MWALK_NOREADONLY)
def isNodeParent (parentNode, testChildren):
for possibleChild in testChildren:
testNode = possibleChild
while testNode and testNode != db:
if testNode == parentNode:
return MG_TRUE
testNode = mgGetParent(testNode)
return MG_FALSE
switchDepth = 0
def checkSwitch (db, parent, rec, data):
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth + 1
return MG_TRUE
def deleteNonSwitchNodes (db, parent, rec, deleteList):
global switchList
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth -1
# Switch depth tells us if we are under a switch
# Still need to see if we have a switch as a child
elif mgGetCode(rec) == fltGroup:
if switchDepth < 1 and not isNodeParent(rec, switchList) and not rec == db:
deleteList.append(mgGetName(rec))
return MG_TRUE
deleteList = []
mgWalk (db, checkSwitch, deleteNonSwitchNodes, deleteList, MWALK_NOREADONLY)
ok = mgCloseDb (db)
if ok == MG_FALSE:
print("Error closing database\n")
print (len (deleteList))
for d in deleteList:
print (d)
here's a pic
Ah yes, I specifically only deleted group nodes in the script. This can be modified to delete groups and objects. Or all nodes for that matter.
I worry about using a deletelist when having nodes added to the list that could be children of other nodes in the list. dont want to delete a parent then delete a child of a deleted parent. So I just deleted in the postwalk in the one below and added objects to the type to delete
db = mgGetCurrentDb()
def gatherSwitchNodes (db, parent, rec, switchList):
if mgGetCode (rec) == fltSwitch:
switchList.append(rec)
return MG_TRUE
switchList = []
mgWalk(db, gatherSwitchNodes, None, switchList, MWALK_NOREADONLY)
def isNodeParent (parentNode, testChildren):
for possibleChild in testChildren:
testNode = possibleChild
while testNode and testNode != db:
if testNode == parentNode:
return MG_TRUE
testNode = mgGetParent(testNode)
return MG_FALSE
switchDepth = 0
def checkSwitch (db, parent, rec, data):
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth + 1
return MG_TRUE
def deleteNonSwitchNodes (db, parent, rec, data):
global switchList
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth -1
# Switch depth tells us if we are under a switch
# Still need to see if we have a switch as a child
elif mgGetCode(rec) == fltGroup or mgGetCode(rec) == fltObject:
if switchDepth < 1 and not isNodeParent(rec, switchList) and not rec == db:
mgDelete (rec)
return MG_TRUE
mgWalk (db, checkSwitch, deleteNonSwitchNodes, None, MWALK_NOREADONLY)
I hear you! Thanks!
Hm. I managed to break it anyways. Python crashes!
from mgapilib import *
import sys
mgInit (None, None)
print("\nOpening database: ",sys.argv[1],"\n")
db = mgOpenDb (sys.argv[1])
if db == None:
print(mgGetLastError (), "\n")
mgExit ()
# db = mgGetCurrentDb()
def gatherSwitchNodes (db, parent, rec, switchList):
if mgGetCode (rec) == fltSwitch:
switchNameList.append(mgGetName(rec))
switchList.append(rec)
return MG_TRUE
switchList,switchNameList = [],[]
mgWalk(db, gatherSwitchNodes, None, switchList, MWALK_NOREADONLY)
def isNodeParent (parentNode, testChildren):
for possibleChild in testChildren:
testNode = possibleChild
while testNode and testNode != db:
if testNode == parentNode:
return MG_TRUE
testNode = mgGetParent(testNode)
return MG_FALSE
switchDepth = 0
def checkSwitch (db, parent, rec, data):
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth + 1
return MG_TRUE
def deleteNonSwitchNodes (db, parent, rec, data):
global switchList
global switchNameList
global switchDepth
if mgGetCode (rec) == fltSwitch:
switchDepth = switchDepth -1
# Switch depth tells us if we are under a switch
# Still need to see if we have a switch as a child
elif mgGetCode(rec) == fltGroup or mgGetCode(rec) == fltObject:
if switchDepth < 1 and not isNodeParent(rec, switchList) and not rec == db:
mgDelete (rec)
return MG_TRUE
mgWalk (db, checkSwitch, deleteNonSwitchNodes, None, MWALK_NOREADONLY)
ok = mgWriteDb (db)
if ok == MG_FALSE:
print("### Error writing to database!\n")
ok = mgCloseDb (db)
if ok == MG_FALSE:
print("Error closing database\n")
mgExit()
C:\Presagis\Suite22\OpenFlight_API_22_0\samples\scripts>python parser2.py ablip_complex.flt
I: OpenFlight API version 22.0.0.
I: Loading plugin <OpenFlight Data Dictionary> from <C:/Presagis/Suite22/OpenFlight_API_22_0/bin_x64/release/fltdata.dll>...
I: Site <FLTDATA> registered for plugin <OpenFlight Data Dictionary>.
I: Plugin <OpenFlight Data Dictionary> loaded.
Opening database: ablip_complex.flt
C:\Presagis\Suite22\OpenFlight_API_22_0\samples\scripts>python --version
Python 3.7.6
On the plus side, it does work for my simple case. Just not the complex one.
Oops. It also crashes Creator :(
Shawn
Greetings,
I believe I can edit files to keep or remove nodes based on the type of records encountered during mgWalk.
Is there an API attribute or whatnot that tracks the hierarchy as mgWalk progresses, so that if there is structure on top of the node being removed, and the node is the only child, then the entire branch can be removed instead of just the node at the end of that branch?
Or is that something I have to do myself, and if so, how would I go about doing that?
In a python list I keep track of elements by their position; how would I do this for a flt file hierarchy??
Thx
Shawn