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scope using a try catch and linq

I really have tried with this but just can't quite get it to work.
I have a bunch of files that I am using Linq to parse, but some of them have a field that the others do not have. There is no way of knowing by the file name.
Here is the code that runs against the file:
var update = from d in document.Descendants("Update")
select new
{
OrderNumber = d.Element("OrderNumber").Value,
StopID = d.Element("StopID").Value,
TransmissionTime = d.Element("TransmissionTime").Value,
EventTime = d.Element("PODTime").Value,
recordCreated = d.Element("EventTime").Value,
EventType = d.Element("EventType").Value,
EventCode = d.Element("EventCode").Value,
POD = d.Element("POD").Value,
Note = d.Element("Note").Value,
CustomerID = d.Element("CustomerID").Value,
OrderID = d.Element("OrderID").Value,
StopRef = d.Element("StopRef").Value,
PieceCount = d.Element("PieceCount").Value,
TotalWeight = d.Element("TotalWeight").Value,
DriverID = d.Element("DriverID").Value
};
Now the problem is that some of them do not have the Element("PODTime") so I need a differnet linq query. I was just going to do a try/catch and if it fails run the other one (cludgy I know).
But obviously as soon as I put update in a try/catch I can no longer access it outside of it.
Normally I would just define it before the try/catch - but I can't get that to work here.
I have tried:
System.Linq.Enumerable update = new System.Linq.Enumerable();
But that is not right. If somebody could point me the right direction I would apprecaite it.
Solution:
Using Sledgehammers nudge combined with a Let:
var update = from d in document.Descendants("Update")
let elName = d.Element("PODTime")
select new
{
OrderNumber = d.Element("OrderNumber").Value,
StopID = d.Element("StopID").Value,
TransmissionTime = d.Element("TransmissionTime").Value,
EventTime = (elName != null) ? elName.Value : string.Empty,

You can use the new ?. operator for this:
d.Element("CustomerID")?.Value
Or if you can't use the newest C#, you can write a "Safe" method to wrap all your calls in:
string SafeGetValue(XElement elem)
{
if (elem == null)
return null;
return elem.Value;
}

Sitefinity: Dynamic Content query optimization with field values

I will attempt to be as specific as possible. So we are using Sitefinity 8.1.5800, I have a couple dynamic content modules named ReleaseNotes and ReleaseNoteItems. ReleaseNotes has some fields but no reference to ReleaseNoteItems.
Release Note Items has fields and a related data field to ReleaseNotes.
So I can query all ReleaseNoteItems as dynamic content pretty quickly less than a second.
I then use these objects provided by sitefinity and map them to a C# object so I can use strong type. This mapping process is taking almost a minute and using over 600 queries for only 322 items (N+1).
In Short: I need to get all sitefinity objects and Map them to a usable c# object quicker than I currently am.
The method for fetching the dynamic content items (takes milliseconds):
private IList<DynamicContent> GetAllLiveReleaseNoteItemsByReleaseNoteParentId(Guid releaseNoteParentId)
{
DynamicModuleManager dynamicModuleManager = DynamicModuleManager.GetManager(String.Empty);
Type releasenoteitemType = TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.ReleaseNoteItems.Releasenoteitem");
string releaseNoteParentTypeString = "Telerik.Sitefinity.DynamicTypes.Model.ReleaseNotes.Releasenote";
var provider = dynamicModuleManager.Provider as OpenAccessDynamicModuleProvider;
int? totalCount = 0;
var cultureName = "en";
Thread.CurrentThread.CurrentUICulture = new CultureInfo(cultureName);
Type releasenoteType = TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.ReleaseNotes.Releasenote");
// This is how we get the releasenote items through filtering
DynamicContent myCurrentItem = dynamicModuleManager.GetDataItem(releasenoteType, releaseNoteParentId);
var myMasterParent =
dynamicModuleManager.Lifecycle.GetMaster(myCurrentItem) as DynamicContent;
var relatingItems = provider.GetRelatedItems(
releaseNoteParentTypeString,
"OpenAccessProvider",
myMasterParent.Id,
string.Empty,
releasenoteitemType,
ContentLifecycleStatus.Live,
string.Empty,
string.Empty,
null,
null,
ref totalCount,
RelationDirection.Parent).OfType<DynamicContent>();
IList<DynamicContent> allReleaseNoteItems = relatingItems.ToList();
return allReleaseNoteItems;
}
This is the method that takes almost a minute that is mapping sitefinity object to C# object:
public IList<ReleaseNoteItemModel> GetReleaseNoteItemsByReleaseNoteParent(ReleaseNoteModel releaseNoteItemParent)
{
return GetAllLiveReleaseNoteItemsByReleaseNoteParentId(releaseNoteItemParent.Id).Select(rn => new ReleaseNoteItemModel
{
Id = rn.Id,
Added = rn.GetValue("Added") is bool ? (bool)rn.GetValue("Added") : false,
BugId = rn.GetValue<string>("bug_id"),
BugStatus = rn.GetValue<Lstring>("bugStatus"),
Category = rn.GetValue<Lstring>("category"),
Component = rn.GetValue<Lstring>("component"),
#Content = rn.GetValue<Lstring>("content"),
Criticality = rn.GetValue<Lstring>("criticality"),
Customer = rn.GetValue<string>("customer"),
Date = rn.GetValue<DateTime?>("date"),
Grouped = rn.GetValue<string>("grouped"),
Override = rn.GetValue<string>("override"),
Patch_Num = rn.GetValue<string>("patch_num"),
PublishedDate = rn.PublicationDate,
Risk = rn.GetValue<Lstring>("risk"),
Title = rn.GetValue<string>("Title"),
Summary = rn.GetValue<Lstring>("summary"),
Prod_Name = rn.GetValue<Lstring>("prod_name"),
ReleaseNoteParent = releaseNoteItemParent,
McProductId = GetMcProductId(rn.GetRelatedItems("McProducts").Cast<DynamicContent>()),
}).ToList();
}
Is there any way to optimize this all into one query or a better way of doing this? Taking almost a minute to map this objects is too long for what we need to do with them.
If there is no way we will have to cache the items or make a SQL query. I would rather not do caching or SQL query if I do not have to.
Thank you in advance for any and all help you can provide, I am new to posting questions on stackoverflow so if you need any additional data please let me know.

Is there a reason why you are doing a .ToList() for the items? Is it possible for you to avoid that. In my opinion, most of the time(of the 1 minute) is taken to convert all your items into a list. Conversion from Sitefinity object to C# object is not the culprit here.

Look Arno's answer here: https://plus.google.com/u/0/112295105425490148444/posts/QrsVtxj1sCB?cfem=1
You can use the "Content links manager" to query dynamic modules relationships (both by parent -ParentItemId- or by child -ChildItemId-) much faster:
var providerName = String.Empty;
var parentTitle = "Parent";
var relatedTitle = "RelatedItem3";
DynamicModuleManager dynamicModuleManager = DynamicModuleManager.GetManager(providerName);
Type parentType = TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.ParentModules.ParentModule");
Type relatedType = TypeResolutionService.ResolveType("Telerik.Sitefinity.DynamicTypes.Model.RelatedModules.RelatedModule");
ContentLinksManager contentLinksManager = ContentLinksManager.GetManager();
// get the live version of all parent items
var parentItems = dynamicModuleManager.GetDataItems(parentType).Where(i => i.GetValue<string>("Title").Contains(parentTitle) && i.Status == ContentLifecycleStatus.Live && i.Visible);
// get the ids of the related items.
// We use the OriginalContentId property since we work with the live vesrions of the dynamic modules
var parentItemIds = parentItems.Select(i => i.OriginalContentId).ToList();
// get the live versions of all the schedules items
var relatedItems = dynamicModuleManager.GetDataItems(relatedType).Where(i => i.Status == ContentLifecycleStatus.Live && i.Visible && i.GetValue<string>("Title").Contains(relatedTitle));
// get the content links
var contentLinks = contentLinksManager.GetContentLinks().Where(cl => cl.ParentItemType == parentType.FullName && cl.ComponentPropertyName == "RelatedField" && parentItemIds.Contains(cl.ParentItemId) && cl.AvailableForLive);
// get the IDs of the desired parent items
var filteredParentItemIds = contentLinks.Join<ContentLink, DynamicContent, Guid, Guid>(relatedItems, (cl) => cl.ChildItemId, (i) => i.OriginalContentId, (cl, i) => cl.ParentItemId).Distinct();
// get the desired parent items by the filtered IDs
var filteredParentItems = parentItems.Where(i => filteredParentItemIds.Contains(i.OriginalContentId)).ToList();

I would imagine that every release note item under a single release note would be related to the same product wouldn't it?
If so, do you need to do the GetMcProductId method for every item?

Include properties based on conditions in anonymous types

Supposing I have the following anonymous type
var g = records.Select(r => new
{
Id = r.CardholderNo,
TimeIn = r.ArriveTime,
TimeOut = r.LeaveTime,
});
Is it possible to do something like the following:
var g = records.Select(r => new
{
Id = r.CardholderNo,
if (condition)
{
TimeIn = r.ArriveTime;
},
TimeOut = r.LeaveTime,
//many more properties that I'd like to be dependant on conditions.
});
How can I achieve an anonymous type based on conditions?

You can do this by using the ternary operator: ?:
The syntax is like this:
TimeIn = condition ? r.ArriveTime : (DateTime?)null // Or DateTime.Min or whatever value you want to use as default
UPDATE
After thinking about your problem for a couple of minutes I came up with the following code that you should never ever use ;)
using System;
class Program
{
static void Main(string[] args)
{
DateTime dt = DateTime.Now;
bool condition = true;
dynamic result = condition ?
(object)new
{
id = 1,
prop = dt
}
:
(object)new
{
id = 2,
};
Console.WriteLine(result.id);
if (condition) Console.WriteLine(result.prop);
}
}
This code should never be used in production because of it's terrible readability and it's really error prone. However, as a learning example of what's possible with the language it's quite nice.

Not directly using an if statement, but you could do it using the ternary operator (assuming TimeIn is of type DateTime):
var g = records.Select(r => new
{
Id = r.CardholderNo,
TimeIn = condition ? r.ArriveTime : (DateTime?)null;
TimeOut = r.LeaveTime
});
Note this will make the property always appear in your Annonymous Type. If this isn't the desired behavior, then you can't do it this way.
I would suggest thinking about the readability of your code and not only about "how can i shorten these few lines so it looks neat".

No. Anonymous types are just like any other type. It has a fixed list of properties. You can't dynamically add or remove properties.
I suggest to either set the property to null, like in the other answers, or use a Dictionary where you add the relevant properties and their values.

If you really need an if (or any another statement) in your Anonymous Type creation, you can try this not-so-pretty solution:
var g = records.Select(r => new
{
Id = r.CardholderNo,
TimeIn = new Func<DateTime?, DateTime?>(x =>
{
if (...)
return x;
else
return null;
}).Invoke(r.ArriveTime),
TimeOut = r.LeaveTime,
});

How do I nest this LINQ query?

I have an XML document from a web service that I am trying to query. However, I am not sure how to query the XML when it has elements nested inside other elements.
Here is a section of the XML file (I haven't included all of it because it's a long file):
<response>
<display_location>
<full>London, United Kingdom</full>
<city>London</city>
<state/>
<state_name>United Kingdom</state_name>
<country>UK</country>
<country_iso3166>GB</country_iso3166>
<zip>00000</zip>
<magic>553</magic>
<wmo>03772</wmo>
<latitude>51.47999954</latitude>
<longitude>-0.44999999</longitude>
<elevation>24.00000000</elevation>
</display_location>
<observation_location>
<full>London,</full>
<city>London</city>
<state/>
<country>UK</country>
<country_iso3166>GB</country_iso3166>
<latitude>51.47750092</latitude>
<longitude>-0.46138901</longitude>
<elevation>79 ft</elevation>
</observation_location>
I can query "one section at a time" but I'm constructing an object from the LINQ. For example:
var data = from i in weatherResponse.Descendants("display_location")
select new Forecast
{
DisplayFullName = i.Element("full").Value
};
var data = from i in weatherResponse.Descendants("observation_location")
select new Forecast
{
ObservationFullName = i.Element("full").Value
};
And my "Forecast" class is basically just full of properties like this:
class Forecast
{
public string DisplayFullName { get; set; };
public string ObservationFullName { get; set; };
//Lots of other properties that will be set from the XML
}
However, I need to "combine" all of the LINQ together so that I can set all the properties of the object. I have read about nested LINQ but I do not know how to apply it to this particular case.
Question: How do I go about "nesting/combining" the LINQ so that I can read the XML and then set the appropriate properties with said XML?

One possible way :
var data = from i in weatherResponse.Descendants("response")
select new Forecast
{
DisplayFullName = (string)i.Element("display_location").Element("full"),
ObservationFullName = (string)i.Element("observation_location").Element("full")
};

Another way ... I prefer using the Linq extension methods in fluent style
var results = weatherResponse.Descendants()
.SelectMany(d => d.Elements())
.Where(e => e.Name == "display_location" || e.Name == "observation_location")
.Select(e =>
{
if(e.Name == "display_location")
{
return new ForeCast{ DisplayFullName = e.Element("full").Value };
}
else if(e.Name == "observation_location")
{
return new ForeCast{ ObservationFullName = e.Element("full").Value };
}
else
{
return null;
}
});

My code is very inefficient for this simple Linq usage

I have the following method that is supposed to parse information from an XML response and return a collection of users.
I've opted into creating a Friend class and returning a List<Friend> to the calling method.
Here's what I have so far, but I noticed that the ids.ToList().Count method parses every single id element to a List, then does it again in the for conditional. It's just super ineffective.
public List<Friend> FindFriends()
{
List<Friend> friendList = new List<Friend>();
var friends = doc.Element("ipb").Element("profile").Element("friends").Elements("user");
var ids = from fr in friends
select fr.Element("id").Value;
var names = from fr in friends
select fr.Element("name").Value;
var urls = from fr in friends
select fr.Element("url").Value;
var photos = from fr in friends
select fr.Element("photo").Value;
if (ids.ToList().Count > 0)
{
for (int i = 0; i < ids.ToList().Count; i++)
{
Friend buddy = new Friend();
buddy.ID = ids.ToList()[i];
buddy.Name = names.ToList()[i];
buddy.URL = urls.ToList()[i];
buddy.Photo = photos.ToList()[i];
friendList.Add(buddy);
}
}
return friendList;
}

First question - do you have to return a List<Friend>? Can you return an IEnumerable<Friend> instead? If so, performance gets a lot better:
IEnumerable<Friend> FindFriends()
{
return doc.Descendants("user").Select(user => new Friend {
ID = user.Element("id").Value,
Name = user.Element("name").Value,
Url = user.Element("url").Value,
Photo = user.Element("photo").Value
});
}
Rather than actually creating new buckets and stuffing values into them, this creates a projection, or a new object that simply contains all of the logic for how to create the new Friend objects without actually creating them. They get created when the caller eventually starts to foreach over the IEnumerable. This is called "deferred execution".
This also makes one assumption - All the <user> nodes in your XML fragment are friends. If that isn't true, the first part of the XML selection might need to be a little more complex.
And as #anon points out, even if you do need to return a List<Friend> for some reason not obvious from the information you've provided, you can just call .ToList() at the end of the return statement. This will just execute the projection I described above straight into a new bucket, so you only ever create one.

Why do you need the separate ids/names/urls/photos variables? Combine it all. You can eliminate the ToList() call if you don't need a List.
List<Friend> friendList = (from f in doc.Element("ipb").Element("profile").Element("friends").Elements("user")
select new Friend() {
ID = f.Element("id").Value,
Name = f.Element("name").Value,
URL = f.Element("url").Value,
Photo = f.Element("photo").Value
}).ToList();
return friendList;