Looping through XMLNodeList problem
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Can you post fuller code? Also is the code being called the correct number of times (ie twice) even if the code is only setting from one node? [Edit] I ran this scratch code:
XmlDocument xmlDoc = new XmlDocument(); xmlDoc.LoadXml("<HotelAvail><Rooms><Room><RoomRQId>1</RoomRQId><Quantity>1</Quantity><NumAdults>3</NumAdults></Room><Room><RoomRQId>2</RoomRQId><Quantity>1</Quantity><NumAdults>2</NumAdults></Room></Rooms></HotelAvail>"); XmlNodeList nodeRooms = xmlDoc.SelectNodes("HotelAvail/Rooms/Room"); foreach (XmlNode objRNode in nodeRooms) { Console.Write(objRNode\["RoomRQId"\].InnerText); Console.Write("\\t"); Console.Write(objRNode\["Quantity"\].InnerText); Console.Write("\\t"); Console.WriteLine(objRNode\["NumAdults"\].InnerText); } Console.ReadKey();This code outputs as expected: 1 1 3 2 1 2 So it is something else inside the loop causing the problem
CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
modified on Monday, January 11, 2010 6:20 AM
The entire project is huge and references several classes, so it's impossible to include the whole code, below is a more concise example of what is occuring. Basically for every occurence of the "Room" node, I populate a datatable with the variables, and then write an output. It loops through my for each loop twice, but sets the variables each time to the first occurence only. And therefore I get two nodes output, which are both derived from the first datatable created, and the first set of room child nodes in the xml document. The rest of this project is working 100% perfectly, but this is the only area where I need to loop through a list of nodes, as all other nodes occur once. XmlNodeList nodeRooms = xmlDoc.SelectNodes("/test:HotelAvail/test:Rooms/test:Room", ns); foreach (XmlNode objRNode in nodeRooms) { intRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText); strQuantity = objRNode["Quantity"].InnerText; intNumAdults = int.Parse(objRNode["NumAdults"].InnerText); DataTable dt = objAvailability.SelectHotelAvail(intRoomRQId, strQuantity, intNumAdults); if (dt.Rows.Count >0) { objWriter.WriteStartElement("Room"); objWriter.WriteStartElement("RoomRQId"); objWriter.WriteString(intRoomRQId.ToString()); objWriter.WriteEndElement(); //RoomRQID ..... other items from datatable are written here } }
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The entire project is huge and references several classes, so it's impossible to include the whole code, below is a more concise example of what is occuring. Basically for every occurence of the "Room" node, I populate a datatable with the variables, and then write an output. It loops through my for each loop twice, but sets the variables each time to the first occurence only. And therefore I get two nodes output, which are both derived from the first datatable created, and the first set of room child nodes in the xml document. The rest of this project is working 100% perfectly, but this is the only area where I need to loop through a list of nodes, as all other nodes occur once. XmlNodeList nodeRooms = xmlDoc.SelectNodes("/test:HotelAvail/test:Rooms/test:Room", ns); foreach (XmlNode objRNode in nodeRooms) { intRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText); strQuantity = objRNode["Quantity"].InnerText; intNumAdults = int.Parse(objRNode["NumAdults"].InnerText); DataTable dt = objAvailability.SelectHotelAvail(intRoomRQId, strQuantity, intNumAdults); if (dt.Rows.Count >0) { objWriter.WriteStartElement("Room"); objWriter.WriteStartElement("RoomRQId"); objWriter.WriteString(intRoomRQId.ToString()); objWriter.WriteEndElement(); //RoomRQID ..... other items from datatable are written here } }
Seems to me intRoomRQId is updating as it should, and the bug is inside SelectHotelAvail(), returning the same row over and over for unknown reasons. :)
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The entire project is huge and references several classes, so it's impossible to include the whole code, below is a more concise example of what is occuring. Basically for every occurence of the "Room" node, I populate a datatable with the variables, and then write an output. It loops through my for each loop twice, but sets the variables each time to the first occurence only. And therefore I get two nodes output, which are both derived from the first datatable created, and the first set of room child nodes in the xml document. The rest of this project is working 100% perfectly, but this is the only area where I need to loop through a list of nodes, as all other nodes occur once. XmlNodeList nodeRooms = xmlDoc.SelectNodes("/test:HotelAvail/test:Rooms/test:Room", ns); foreach (XmlNode objRNode in nodeRooms) { intRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText); strQuantity = objRNode["Quantity"].InnerText; intNumAdults = int.Parse(objRNode["NumAdults"].InnerText); DataTable dt = objAvailability.SelectHotelAvail(intRoomRQId, strQuantity, intNumAdults); if (dt.Rows.Count >0) { objWriter.WriteStartElement("Room"); objWriter.WriteStartElement("RoomRQId"); objWriter.WriteString(intRoomRQId.ToString()); objWriter.WriteEndElement(); //RoomRQID ..... other items from datatable are written here } }
I edited my last post with some scratch code based on yours, it is iterating through correctly. The things that are different (on mine) are: 1. I don't have any namespaces. 2. I had to modify the XML you posted to have a root element The code you have posted just looks like it should work OK to me. A few things to check: a. I assume you've done this alread, but put a breakpoint at the start of the
foreachloop and inspected thenodeRoomslist manually, and checked theobjNodeobject at each iteration. b. I assumeintRoomRQId,strQuantity,intNumAdultsvalue types (string, int etc) otherwise there is a dangerobjAvailability.SelectHotelAvail(intRoomRQId, strQuantity, intNumAdults);will change them. c. Do you have more than oneRoomsnode? Also, how can you tell that only the first set of values are being used (e.g. from, the database table, by breakpoint), related to this, what is objWriter? It is possible that the writer is not wroking correctly.CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
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I edited my last post with some scratch code based on yours, it is iterating through correctly. The things that are different (on mine) are: 1. I don't have any namespaces. 2. I had to modify the XML you posted to have a root element The code you have posted just looks like it should work OK to me. A few things to check: a. I assume you've done this alread, but put a breakpoint at the start of the
foreachloop and inspected thenodeRoomslist manually, and checked theobjNodeobject at each iteration. b. I assumeintRoomRQId,strQuantity,intNumAdultsvalue types (string, int etc) otherwise there is a dangerobjAvailability.SelectHotelAvail(intRoomRQId, strQuantity, intNumAdults);will change them. c. Do you have more than oneRoomsnode? Also, how can you tell that only the first set of values are being used (e.g. from, the database table, by breakpoint), related to this, what is objWriter? It is possible that the writer is not wroking correctly.CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
Here is a complete XML snapshot: <?xml version="1.0" encoding="utf-8">; <HotelAvail xmlns="http://www.transhotel.com/transHotel/2004A" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.transhotel.com/transHotel/2004A HotelAvailRQ.xsd"> <WholesalerID>TRANSHOTEL</WholesalerID> <Hotels> <HotelCode>1154718</HotelCode> </Hotels> <Dates> <CheckIn>2010-01-21</CheckIn> <CheckOut>2010-01-22</CheckOut> </Dates> <Rooms> <Room> <RoomRQId>1</RoomRQId> <Quantity>1</Quantity> <NumAdults>3</NumAdults> </Room> <Room> <RoomRQId>2</RoomRQId> <Quantity>1</Quantity> <NumAdults>2</NumAdults> </Room> </Rooms> </HotelAvail> If I run in debug mode, on the first pass through ForEach it says that the innertext will be 113 (for the whole occurrence of that node), on the second pass it says that the innertext will be 212 (which is correct). So the problem has got to be how the variables are set from the referenced nodes. For some reason it is selecting the 1st occurence of each element within Room even though it is running within a loop. I know this can be a problem with say SelectSingleNode, but I'm not using that. So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document. A namespace is used and referenced as follows: XmlNamespaceManager ns = new XmlNamespaceManager(xmlDoc.NameTable); ns.AddNamespace("test", "http://www.transhotel.com/transHotel/2004A"); There is only one "Rooms" node, so that is selected explicitly so as to ensure no confusion. Objwriter is an XMLTextWriter which is merely writing the output.
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Here is a complete XML snapshot: <?xml version="1.0" encoding="utf-8">; <HotelAvail xmlns="http://www.transhotel.com/transHotel/2004A" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.transhotel.com/transHotel/2004A HotelAvailRQ.xsd"> <WholesalerID>TRANSHOTEL</WholesalerID> <Hotels> <HotelCode>1154718</HotelCode> </Hotels> <Dates> <CheckIn>2010-01-21</CheckIn> <CheckOut>2010-01-22</CheckOut> </Dates> <Rooms> <Room> <RoomRQId>1</RoomRQId> <Quantity>1</Quantity> <NumAdults>3</NumAdults> </Room> <Room> <RoomRQId>2</RoomRQId> <Quantity>1</Quantity> <NumAdults>2</NumAdults> </Room> </Rooms> </HotelAvail> If I run in debug mode, on the first pass through ForEach it says that the innertext will be 113 (for the whole occurrence of that node), on the second pass it says that the innertext will be 212 (which is correct). So the problem has got to be how the variables are set from the referenced nodes. For some reason it is selecting the 1st occurence of each element within Room even though it is running within a loop. I know this can be a problem with say SelectSingleNode, but I'm not using that. So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document. A namespace is used and referenced as follows: XmlNamespaceManager ns = new XmlNamespaceManager(xmlDoc.NameTable); ns.AddNamespace("test", "http://www.transhotel.com/transHotel/2004A"); There is only one "Rooms" node, so that is selected explicitly so as to ensure no confusion. Objwriter is an XMLTextWriter which is merely writing the output.
jamesc69 wrote:
If I run in debug mode, on the first pass through ForEach it says that the innertext will be 113 (for the whole occurrence of that node), on the second pass it says that the innertext will be 212 (which is correct).
OK, so we've eliminated two possibilities: The
xmlDoc.SelectNodesis selecting the node correctly and the loop is iterating over the nodes correctly.jamesc69 wrote:
I know this can be a problem with say SelectSingleNode, but I'm not using that. So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Correct
_xmlnode_["_NodeName_"].InnerTextis not iterative, however you are the source_xmlnode_(in your case objRNode) is the result of an interation. So you will get theobjRNode["RoomRQId"].InnerTextwill get theInnerTextof the currentobjRNode'sRoomRQIdcorrectly. Both the code I posted earlier shows that to be the case and Luc Pattyn has tested it.jamesc69 wrote:
So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Not necessarily (see above). It is possible that, as Luc said,
SelectHotelAvail()is fouling up somehow. It is possible that the output code is not working as expected, or that somehow the value is being set in another place (e.g. later in the code, concurrency problems). Without full source code this is hard to find. The lineintRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText);should get the correct Id. I'd use a breakpoint to ensure that correct ID is being set by that line, then step through to see if it changes.CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
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jamesc69 wrote:
If I run in debug mode, on the first pass through ForEach it says that the innertext will be 113 (for the whole occurrence of that node), on the second pass it says that the innertext will be 212 (which is correct).
OK, so we've eliminated two possibilities: The
xmlDoc.SelectNodesis selecting the node correctly and the loop is iterating over the nodes correctly.jamesc69 wrote:
I know this can be a problem with say SelectSingleNode, but I'm not using that. So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Correct
_xmlnode_["_NodeName_"].InnerTextis not iterative, however you are the source_xmlnode_(in your case objRNode) is the result of an interation. So you will get theobjRNode["RoomRQId"].InnerTextwill get theInnerTextof the currentobjRNode'sRoomRQIdcorrectly. Both the code I posted earlier shows that to be the case and Luc Pattyn has tested it.jamesc69 wrote:
So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Not necessarily (see above). It is possible that, as Luc said,
SelectHotelAvail()is fouling up somehow. It is possible that the output code is not working as expected, or that somehow the value is being set in another place (e.g. later in the code, concurrency problems). Without full source code this is hard to find. The lineintRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText);should get the correct Id. I'd use a breakpoint to ensure that correct ID is being set by that line, then step through to see if it changes.CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
keefb wrote:
and Luc Pattyn has tested it.
No, you misunderstood. I did not test anything, it just seemed from code+observations that the bug was probably inside the method of which no code was shown at all. :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
Happy New Year to all.
We hope 2010 soon brings us automatic PRE tags!
Until then, please insert them manually.
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keefb wrote:
and Luc Pattyn has tested it.
No, you misunderstood. I did not test anything, it just seemed from code+observations that the bug was probably inside the method of which no code was shown at all. :)
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
Happy New Year to all.
We hope 2010 soon brings us automatic PRE tags!
Until then, please insert them manually.
Apologies, I thought you'd run some code like mine... ;-)
CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
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jamesc69 wrote:
If I run in debug mode, on the first pass through ForEach it says that the innertext will be 113 (for the whole occurrence of that node), on the second pass it says that the innertext will be 212 (which is correct).
OK, so we've eliminated two possibilities: The
xmlDoc.SelectNodesis selecting the node correctly and the loop is iterating over the nodes correctly.jamesc69 wrote:
I know this can be a problem with say SelectSingleNode, but I'm not using that. So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Correct
_xmlnode_["_NodeName_"].InnerTextis not iterative, however you are the source_xmlnode_(in your case objRNode) is the result of an interation. So you will get theobjRNode["RoomRQId"].InnerTextwill get theInnerTextof the currentobjRNode'sRoomRQIdcorrectly. Both the code I posted earlier shows that to be the case and Luc Pattyn has tested it.jamesc69 wrote:
So therefore objRNode["RoomRQId"].InnerText is not iterative, and is always picking the 1st occurence with the document.
Not necessarily (see above). It is possible that, as Luc said,
SelectHotelAvail()is fouling up somehow. It is possible that the output code is not working as expected, or that somehow the value is being set in another place (e.g. later in the code, concurrency problems). Without full source code this is hard to find. The lineintRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText);should get the correct Id. I'd use a breakpoint to ensure that correct ID is being set by that line, then step through to see if it changes.CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
Hi, First of all thanks all for your help, but this apparently isn't a coding problem, but actually a problem with my Vis Studio. My Vis Studio was not building a new dll each time and therefore any change I was making was having no effect. I created a new solution, added all the existing files into the new solution, and guess what - it now works! Apologies for wasting everyone's time.
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Hi, First of all thanks all for your help, but this apparently isn't a coding problem, but actually a problem with my Vis Studio. My Vis Studio was not building a new dll each time and therefore any change I was making was having no effect. I created a new solution, added all the existing files into the new solution, and guess what - it now works! Apologies for wasting everyone's time.
Glad you got it sorted!
CCC solved so far: 2 (including a Hard One!) 37!?!! - Randall, Clerks
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Hi, I have XML in the following structure: <Rooms> <Room> <RoomRQId>1</RoomRQId> <Quantity>1</Quantity> <NumAdults>3</NumAdults> </Room> <Room> <RoomRQId>2</RoomRQId> <Quantity>1</Quantity> <NumAdults>2</NumAdults> </Room> </Rooms> And each time, I get the values assigned as the first occurence of room. Running in debug mode, I can see the second node called within the For each loop, but the values are still assigned as the second occurence. Code below: XmlNodeList nodeRooms = xmlDoc.SelectNodes("/test:HotelAvail/test:Rooms/test:Room", ns); foreach (XmlNode objRNode in nodeRooms) { intRoomRQId = int.Parse(objRNode["RoomRQId"].InnerText); strQuantity = objRNode["Quantity"].InnerText; intNumAdults = int.Parse(objRNode["NumAdults"].InnerText); } So IntRoomRQID is set as 1 twice, when it should create a node of 1, and then a node of value 2.
Is there a reason you're not using linq-to-xml? It's much simpler (types from memory, so you may need to tweak it a bit)...
XDocument doc = XDocument.Load("myfile.xml");
XElement root = doc.Element["Rooms"];
foreach (XElement element in root.Elements)
{
int roomID = Convert.ToInt32(element.Element["RoomRQID"].Value);
int quantity = Convert.ToInt32(element.Element["Quantity"].Value);
int numAdults = Convert.ToInt32(element.Element["NumAdults"].Value);
}No messing around with
InnerTextand that kind of crap..45 ACP - because shooting twice is just silly
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