Develop Reference

How to reference property of another object if the current object's property is null

I have a public Dictionary<string, PostRenewalActionJobs> Jobs to store some actions I would like to trigger for specific accounts, the key of this dictionary being the account name.
public class PostRenewalActionJobs
{
public List<AlterDatabaseLinkJob> AlterDataBaseLink { get; set; }
public DatabaseConnectionCheckJob DatabaseConnectionCheck { get; set; }
public UnlockDatabaseAccountJob UnlockDatabaseAccount { get; set; }
public LinuxConnectionCheckJob LinuxConnectionCheck { get; set; }
public WindowsConnectionCheckJob WindowsConnectionCheck { get; set; }
public ReplacePasswordInFileJob ReplacePasswordInFile { get; set; }
}
The properties of PostRenewalActionJobs type (AlterDataBaseLink, DatabaseConnectionCheck, etc) can be defined for a specific account or for all accounts by using * as key in the dictionary:
By using below method I am able to retrieve the jobs for an account (if exists) or the general jobs:
public PostRenewalActionJobs GetJobsForAccount(string accountName)
{
return Jobs.ContainsKey(accountName) ? Jobs[accountName] : Jobs["*"];
}
I would like to have a dynamic way of getting a job from the all accounts object ("*") if the one from the specific account is null.
Something like below but whit out repeating the same code for all job types and also a solution that should work when new job types are introduced.
var dbConCheckJob = GetJobsForAccount("someAccount").AlterDataBaseLink;
if(dbConCheckJob == null || !dbConCheckJob.Any())
{
dbConCheckJob = GetJobsForAccount("*").AlterDataBaseLink
}
I was thinking to use some reflection, but I am not sure how to do it.

You don't need to use reflection. You can already determine whether to get the specific jobs for an account or the generic ones, you could then use a Func to get the job you want:
public TJob GetPostJobForAccount<TJob>(string accountName,
Func<PostRenewalActionJobs, TJob> jobSelector) where TJob : JobBase
{
var genericJobs = Jobs["*"];
var accountJobs = Jobs.ContainsKey(accountName) ? Jobs[accountName] : genericJobs;
// Account might be defined but without any job of the given type
// hence selecting from the defaults if need be
return jobSelector(accountJobs) ?? jobSelector(genericJobs);
}
var bobJob = GetPostJobForAccount("bob", x => x.WindowsConnectionCheck);
var aliceJob = GetPostJobForAccount("alice", x => x.UnlockDatabaseAccount);

I found a way to do it, not sure if there is a better way:
public TJob GetPostJobForAccount<TJob>(string accountName)
{
Type type = typeof(PostRenewalActionJobs);
var accountJobs = Jobs[accountName];
var generalJobs = Jobs["*"];
foreach (var item in type.GetProperties())
{
var itemType = item.PropertyType;
var currentType = typeof(TJob);
if (itemType != currentType)
{
continue;
}
var output = (TJob)accountJobs?.GetType()?.GetProperty(item.Name)?.GetValue(accountJobs, null);
if (output is null)
{
output = (TJob)accountJobs?.GetType()?.GetProperty(item.Name)?.GetValue(generalJobs, null);
}
return output;
}
return default;
}

can not convert the class to System.Linq.IQueryable using .net core

Here i have a class:
public class AccessinfoDetails
{
public IEnumerable<TurbineDvce> Devices { get; set; }
public TixiModem TixiModem { get; set; }
}
i have an interface which i defined like this:
public IQueryable<AccessinfoDetails> Devices(string id);
for the implemntation of the interface:
public IQueryable<AccessinfoDetails> Devices(string id){
AccessinfoDetails result = new AccessinfoDetails()
{
Devices = distinct,
TixiModem = tixiModem
};
return result;}
but i get an error saying it can not convert AcessInfoDeatils to system.linq.iquerable
which is right,but how can i fix it and is it a right way to pass data to my API controller?

This should work, change your return line to look like this:
return new [] {result}.AsQuerable();
or as Rufus L points out in the comments a typed version using list instead of array:
return new List<AccessinfoDetails> { result }.AsQueryable();

The return type of the method is IQueryable <AccessinfoDetails>, it is a data collection, but the "result" in the method is a single data of type AccessinfoDetails.Not clear about your scenario.
If you don't want to change the return type of the method, you should change the method as shown:
public IQueryable<AccessinfoDetails> Devices(string id)
{
List<AccessinfoDetails> list = new List<AccessinfoDetails>()
{
new AccessinfoDetails
{
Devices = distinct,
ixiModem = tixiModem
}
};
return list.AsQueryable();
}

Turn array into a POCO object

I'm having trouble converting the following string array into a POCO object.
Given the following:
string files = [
"./Folder/file.ext",
"./Folder/file2.ext",
"./Folder/file3.ext",
"./Folder/nestedfolder/file.ext",
"./Folder2/file1.ext",
"./Folder2/file2.ext",
"./file1.ext",
"./file2.ext",
"./file3.ext",
];
I would like to convert it to something like:
public class HierarchicalSource{
public List<HierarchicalSource> Children = new List <HierarchicalSource> ();
public bool folder { get; set; }
public string FullPath;
public HierarchicalSourceSource(string path) {
this.FullPath = path;
}
}
Where HierarchicalSource is the root, and has a list of children
UPDATE:
I ended up changing the list to a dictionary. There must be a more efficient way to do this, but I did as follows:
string fileList = files.Select(x => x.Remove(0, 2)).ToArray();
var root = new HierarchicalSource("root");
foreach(var f in fileList){
var current = root;
string[] splitFile = f.Split('/');
foreach(var s in splitFile){
if(!current.Children.ContainsKey(s)){
current.Children.Add(s, new List<HierarchicalSource>{ new HierarchicalSource(s) });
}
current = current.Children[s].Last();
}
}
POCO:
public class HierarchicalSource{
public string name;
public Dictionary<string, List<HierarchicalSource>> Children = new Dictionary<string, List<HierarchicalSource>>();
public HierarchicalSource(string name){
this.name = name;
}
}

If I understand you correctly, this requires looping through the array, but it'll allow you to parse each item in the array so you can generate the HierarchicalNode object's values.
var node = new HierarchicalSource();
foreach(var str in files)
{
var pathParts = str.Split('/').ToList();
node.Children.Add(new HierarchicalNode()
{
FullPath = str,
Folder = pathParts[1] // you may need to do some debugging to see what the results for pathParts are instead of just [#]
});
}
Since the FullPath member in HierarchicalNode is public you can set that value without having to go through any constructor.
// using the above code for reference
node.FullPath = whateverThePathYouNeedIs;
Also update that property in the class to use getters and setters
public string FullPath { get; set; }

Reflection on IQueryable<T> can't find property

I created a custom gridview control and exported it into a dll so I can reuse it. Inside the dll I created a function to get the DataSource, I'm trying to fill a dropdown from there but is failing.
So on my website I have this
public partial class _Management : System.Web.UI.Page
{
public class _ManagementHelper
{
public int ID;
public string CompanyName;
public string ResourceName;
}
protected void Page_Load(object sender, EventArgs e)
{
ucGridViewEx.DataSource = ucGridViewEx_Source();
ucGridViewEx.DataBind();
}
private List<dynamic> ucGridViewEx_Source()
{
var source = dl.ComapniesResources.Select(x => new _ManagementHelper
{
ID = x.ResourceID,
CompanyName = x.Supplier1.SupplierName,
ResourceName = x.Name
});
return ucGridViewEx.GridViewExDataSource(source);
}
Then the custom control inside the dll have this relevant code
public List<dynamic> GridViewExDataSource<T>(IQueryable<T> query)
{
foreach (var column in this.Columns)
{
var gridViewExColumn = column as ColumnEx;
if (gridViewExColumn != null
&& gridViewExColumn.SearchType == SearchTypeEnum.DropDownList)
{
gridViewExColumn.DropDownDataSource = query.GetDropDownDataSource(gridViewExColumn.DataField);
}
}
return ((IQueryable<dynamic>)query).ToList<dynamic>();
}
Function GetDropDownDataSource() is inside another extension class inside the same dll as the gridview
internal static List<ListItem> GetDropDownDataSource<T>(this IQueryable<T> query,
string dataField)
{
var ddlSource = new List<ListItem>();
// x =>
var xParameter = Expression.Parameter(typeof(T), "x");
// x.Property
var propery = typeof(T).GetProperty(dataField);
// x => x.Property
var columnLambda = Expression.Lambda(Expression.Property(xParameter, propery), xParameter);
return ddlSource;
}
Code fails in this where I'm assingning the value to columnLambda because property is null, not because it does not exist (it does) because is not getting any property. I tried with GetProperties() and is not returning anything.
Is curious than this is happening since I moved to the DataSource to select into _ManagementHelper. I was using a dynamic ( Select(x => new {}) ) on ucGridViewEx_Source() before and it worked perfectly. Please don't provide the solution to keep using the dynamic because I need to allow both types, with dynamic and using custom objects.

_ManagementHelper has no property. It just contains three fields (as far as you told us). So GetPrperty returns nothing. Change the members of _ManagementHelper to properties:
public class _ManagementHelper
{
public int ID { get; set; }
public string CompanyName { get; set; }
public string ResourceName { get; set; }
}

I see one bug --
var source = dl.ComapniesResources.Select(x => new _ManagementHelper
{
// ResourceID = x.ResourceID, this was the old code
ID = x.ResourceID, // fixed code
CompanyName = x.Supplier1.SupplierName,
ResourceName = x.Name
});
also, where is ListItem defined?

Using DefaultIfEmpty with an object?

I saw an example on MSDN where it would let you specify the default value if nothing is returned. See below:
List<int> months = new List<int> { };
int firstMonth2 = months.DefaultIfEmpty(1).First();
Is it possible to use this functionality with an object? Example:
class object
{
int id;
string name;
}
code:
List<myObjec> objs = new List<myObjec> {};
string defaultName = objs.DefaultIfEmpty(/*something to define object in here*/).name;
UPDATE:
I was thinking I could do something like this:
List<myObjec> objs = new List<myObjec> {};
string defaultName = objs.DefaultIfEmpty(new myObjec(-1,"test")).name;
But haven't been able to. It should be noted that I am actually trying to use this method on an object defined in my DBML using LINQ-To-SQL. Not sure if that makes a difference in this case or not.

You need to pass an instantiated class as a parameter of the DefaultIfEmpty.
class Program
{
static void Main(string[] args)
{
var lTest = new List<Test>();
var s = lTest.DefaultIfEmpty(new Test() { i = 1, name = "testing" }).First().name;
Console.WriteLine(s);
Console.ReadLine();
}
}
public class Test
{
public int i { get; set; }
public string name { get; set; }
}
To add to it and make it a bit more elegant (IMO) add a default constructor:
class Program
{
static void Main(string[] args)
{
var lTest = new List<Test>();
var s = lTest.DefaultIfEmpty(new Test()).First().name;
Console.WriteLine(s);
Console.ReadLine();
}
}
public class Test
{
public int i { get; set; }
public string name { get; set; }
public Test() { i = 2; name = "testing2"; }
}

As per the MSDN page on this Extension Method you can do what you want:
http://msdn.microsoft.com/en-us/library/bb355419.aspx
Check the sample on this page for an example on how to use this with an object.

i must admit i am not too sure i understand your question, but i'll try to suggest using double question mark if the returned object might be null. Like so:
myList.FirstOrDefault() ?? new myObject();

You can create a default Object Like this:
Object o_Obj_Default = new Object();
o_Obj_Default.id = 3;
o_Obj_Default.name = "C";
And add it to your default value :
string defaultName = objs.DefaultIfEmpty(o_Obj_Default).First().name;
If your list "objs" is empty, the result will be "C"