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To convert if condition to linq in cshtml

Code
if(Model.CurrentStatus == 1 || Model.CurrentStatus == 2)
{
//can display those records..
}
else if((Model.CurrentStatus == 3 || Model.CurrentStatus == 4) && Model.Date != null)
{
if(Model.Date <= 30 days)
{
//can display those records..
}
}
I have tried the following code and unable to complete it fully as expected
#Html.Partial("Filter", new IndexModel()
{
Id = Model.Id,
Collection = Model.Collection.Where((a => a.CurrentStatus == 1 || a.CurrentStatus == 2)
&& )
})
How to convert the above if condition to linq in cshtml. Thanks

the else-if relationship is an OR relationship. So simply combine the two lines. the inner nested if inside the else if is an AND relationship. This would go into the second set of parentheses
Collection = Model.Collection.Where
(
(a => a.CurrentStatus == 1 || a.CurrentStatus == 2) ||
((a.CurrentStatus == 3 || a.CurrentStatus == 4) && a.Date != null && a.Date <= 30)
)
EDIT:
Here is another suggestion: extract the readable code into an own method that evaluates the condition and returns the boolean result. This way you can make a predicate that can be accepted by the Where method:
private bool IsForDisplay( ModelDataType Model )
{
if(Model.CurrentStatus == 1 || Model.CurrentStatus == 2)
{
//can display those records..
return true;
}
else if((Model.CurrentStatus == 3 || Model.CurrentStatus == 4) && Model.Date != null)
{
if(Model.Date <= 30 days)
{
//can display those records..
return true;
}
}
return false;
}
now you can use it simply in the linq expression:
#Html.Partial("Filter", new IndexModel()
{
Id = Model.Id,
Collection = Model.Collection.Where(a => IsForDisplay(a))
});

Store math operator in variable

I am creating an application in C# MVVM. I have a simple question. Is there any possibility to store math operator in variable? I have a code like that:
public ICollectionView FilteredCollection
{
get
{
return filteredCollection;
}
set
{
filteredCollection = value;
OnPropertyChanged("FilteredCollection");
}
}
FilteredCollection.Filter = x => (
(string.IsNullOrEmpty(DynamicSearchEmployeeName) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeName))
&& (DynamicSearchEmployeeID == null || ((Employee)x).EmployeeID == DynamicSearchEmployeeID)
&& (string.IsNullOrEmpty(DynamicSearchEmployeeSalary) || ((Employee)x).EmployeeSalary == Convert.ToInt32(DynamicSearchEmployeeSalary))
&& (string.IsNullOrEmpty(DynamicSearchEmployeeDesigner) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeDesigner))
&& (string.IsNullOrEmpty(DynamicSearchEmployeeEmailID) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeEmailID))
);
What I want to achieve:
In fourth line (DynamicSearchEmployeeSalary) math operator should be depended on following conditions:
if (IsPressedEqual == true)
VARIABLE = "=="
if (IsPressedLess == true)
VARIABLE = "<"
if (IsPressedGreater == true)
VARIABLE = ">"
if (IsPressedLess == true && IsPressedEqual == true)
VARIABLE = "<="
if (IsPressedGreater == true && IsPressedEqual == true)
VARIABLE = ">="
Scenario:
For example I put a value like 10000 in textbox, then click on button with "=" operator. As a result I want to receive Employees with Salary equals than 10000.
Then I click on ">". And I have Employees with Salary greater and equals 10000.
FilteredCollection.Filter = x => (
(string.IsNullOrEmpty(DynamicSearchEmployeeName) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeName))
&& (DynamicSearchEmployeeID == null || ((Employee)x).EmployeeID == DynamicSearchEmployeeID)
&& (string.IsNullOrEmpty(DynamicSearchEmployeeSalary) || ((Employee)x).EmployeeSalary VARIABLE Convert.ToInt32(DynamicSearchEmployeeSalary))
&& (string.IsNullOrEmpty(DynamicSearchEmployeeDesigner) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeDesigner))
&& (string.IsNullOrEmpty(DynamicSearchEmployeeEmailID) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeEmailID))

I've made a simple Rule Based Engine ... I think it will help you in your issue ...
please find it as a nuget package here: https://www.nuget.org/packages/IbnSherien.RuleBasedEngine/
you can create a rule like this:
var rule = RuleEngine.CreateRule<Employee>()
.If<Employee>(e => e.EmployeeSalary).GreaterThan(DynamicSearchEmployeeSalary)
.Validate();
FilteredCollection.Filter = x => (
(string.IsNullOrEmpty(DynamicSearchEmployeeName) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeName))
&& (DynamicSearchEmployeeID == null || ((Employee)x).EmployeeID == DynamicSearchEmployeeID)
&& (string.IsNullOrEmpty(DynamicSearchEmployeeSalary) || rule.Match((Employee)x).IsMatch)
&& (string.IsNullOrEmpty(DynamicSearchEmployeeDesigner) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeDesigner))
&& (string.IsNullOrEmpty(DynamicSearchEmployeeEmailID) || ((Employee)x).EmployeeName.Contains(DynamicSearchEmployeeEmailID))
feel free to add any comments or contribute to the package

c# Multiple Independent Filters on Lambda Query

I've been working on this for hours today and feel like there is an easy way to do this but I am unable to make it work by anything but brute force.
I have an entity in my application that serves as a Mapping between two objects, based on 5 filters. The goal is to find the record with the most specific match to the filters.
Right now, I am manually brute forcing 2^5 queries to get the most specific row, but feel like there has to be a much easier way to do this.
The only gotcha here is that there may be no match in the database for a specific filter (or all), in which case I want to select the NULL record.
Below I have an excerpt of my embarrassing brute force query -- I first want to try and match on all 5 filters, then on permutations of 4 matching, then 3, then 2, then 1, and finally all Nulls.
incList.FirstOrDefault(x =>
x.Filter1 == filter1Parameter && x.Filter2 == filter2Parameter && x.Filter3 == filter3Parameter && x.Filter4 == filter4Parameter && x.Filter5 == filter5Parameter
|| x.Filter1 == null && x.Filter2 == filter2Parameter && x.Filter3 == filter3Parameter && x.Filter4 == filter4Parameter && x.Filter5 == filter5Parameter
|| x.Filter1 == filter1Parameter && x.Filter2 == null && x.Filter3 == filter3Parameter && x.Filter4 == filter4Parameter && x.Filter5 == filter5Parameter
|| x.Filter1 == filter1Parameter && x.Filter2 == filter2Parameter && x.Filter3 == null && x.Filter4 == filter4Parameter && x.Filter5 == filter5Parameter
|| x.Filter1 == filter1Parameter && x.Filter2 == filter2Parameter && x.Filter3 == filter3Parameter && x.Filter4 == null && x.Filter5 == filter5Parameter
|| x.Filter1 == filter1Parameter && x.Filter2 == filter2Parameter && x.Filter3 == filter3Parameter && x.Filter4 == filter4Parameter && x.Filter5 == null
I originally thought I could have a simple statement that would independently grab the value if present, and grab null if not
incList.FirstOrDefault(x => (x.Filter1 == filter1Parameter || x.Filter1 == null) &&
(x.Filter2 == filter2Parameter || x.Filter2 == null) &&
(x.Filter3 == filter3Parameter || x.Filter3 == null) &&
(x.Filter4 == filter4Parameter || x.Filter4 == null) &&
(x.Filter5 == filter5Parameter || x.Filter5 == null));
But that did not work.
Any pointers would be appreciated.

I'm still trying to understand the full extent of the requirement.
However, have you explored abstracting this Func or Func(s) in a separate class. This separate class or classes would operate like a Strategy. Only in charge of what filters a collection based on a certain predicate.
If that does not seem like a good route, what about looking into writing your own implementation IEqualityComparer. This will allow you determine what makes these objects equal.

You can introduce something like a "fitness function" and then select item with max fit value
var bestMatch = incList.Select(x => new
{
item = x,
fit =
(x.Filter1 == null
? 1
: (x.Filter1 == filter1Parameter ? 2 : 0)) *
(x.Filter2 == null
? 1
: (x.Filter2 == filter2Parameter ? 2 : 0)) // and so on
})
.OrderByDescending(x => x.fit)
.FirstOrDefault(x => x.fit > 0)?.item;

List filtering with LINQ

So I came across this method in code:
private void FilterBasedUponPermission(List<Data.Indications.SpWeb_SavedIndications1LightDataObject> list)
{
list.RemoveAll(item =>
(item.Permission == Controllers.Indications.ICConstants.TradeType_LLH && !isLLH) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_ALM && !isALM) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_RealEstate && !isRE) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_Auditor && !isAuditor));
}
However, in the list passed in, some of the permission values are null, and it's keeping them in the filtered list. I want it to remove the items that also don't have a permission set, not just the ones that don't match the permission that you have as a user.
Thanks!

Just add a item.Permission == null
list.RemoveAll(item => item.Permission == null ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_LLH && !isLLH) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_ALM && !isALM) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_RealEstate && !isRE) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_Auditor && !isAuditor));

private void FilterBasedUponPermission(List<Data.Indications.SpWeb_SavedIndications1LightDataObject> list)
{
list.RemoveAll(item =>
(item.Permission == null) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_LLH && !isLLH) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_ALM && !isALM) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_RealEstate && !isRE) ||
(item.Permission == Controllers.Indications.ICConstants.TradeType_Auditor && !isAuditor));
}

Does on of those work?
list.RemoveAll(item => !item.Permission.HasValue); // in case Permission is Nullable<T>
list.RemoveAll(item => item.Permission == null);
You can add all the other conditions after a logical or (||).
Cheers,
Matthias

LINQ Method Syntax - how to accomplish dynamic Linq statements

I use Linq to Entities to retrieve my records from DB. The function below is in a method. Method has some parameters (arguments) like group, datefrom, dateto, place, state , searchtext etc. etc.
the whole idea is if these parameters are not empty or null then accomplish the LINQ statments. The way I'm doing is I'm checking whether there is a value or not. if it has the value then I pass e.g. a.no_group= group if it doesn't has a value then I pass a statement like a.id!=-1, which is always true.
Problem:
I mean I'm not happy with passing in every statement like "a.id != -1" which is always true . I use this because I have to put a value there. But I'm not happy with this way of doing it... (it works!)
Question:
The question is: this right way of doing?
1- Can I replace a.id != -1 with something else ?
2- If you see the whole linq statement is duplicated because of language check. As you see the last
linq statement checks on language 'Dutch' or 'French'... How to avoid dupliation?
3- I'm checking whether the current date (datetime.now) is between date_begin and date_end. Is this correct way...
The whole code works fine, but I think I'm complicating the code which can be much simpler...
But how?
if (Language == ConfBouwHelper.LanguageEnum.French)
{
//FRENCH RECORDS
listAgendaItems = dc.agenda.Where(a =>
((String.IsNullOrEmpty(group)) ? (a.id != -1) : (a.no_group == group))
&& ((activityType.Equals("ALL")) ? (a.id != -1) : (a.type_manifestation == activityType))
&& ((String.IsNullOrEmpty(dateFrom)) ? (a.id != -1) : (a.date_debut.Value >= dateFrom))
&& ((String.IsNullOrEmpty(dateTo)) ? (a.id != -1) : (a.date_debut.Value <= dateTo))
&& ((String.IsNullOrEmpty(place)) ? (a.id != -1) : (a.emplacement.Contains(place)))
&& ((String.IsNullOrEmpty(state)) ? (a.id != -1) : (a.cd_prov == state))
&& ((String.IsNullOrEmpty(searchText)) ? (a.id != -1) : (a.libelle_activite.Contains(searchText)))
&& ((a.date_begin_display.HasValue ? DateTime.Now >= a.date_begin_display.Value : a.id != -1) &&
(a.date_end_display.HasValue ? DateTime.Now <= a.date_end_display.Value : a.id != -1))
&& (a.langue == "FRENCH" || a.langue == "B")).ToList<agenda>(); //GET FRENCH
}
else
//DUTCH RECORDS
{
listAgendaItems = dc.agenda.Where(a =>
((String.IsNullOrEmpty(group)) ? (a.id != -1) : (a.no_group == group))
&& ((activityType.Equals("ALL")) ? (a.id != -1) : (a.type_manifestation == activityType))
&& ((String.IsNullOrEmpty(dateFrom)) ? (a.id != -1) : (a.date_debut.Value >= dateFrom))
&& ((String.IsNullOrEmpty(dateTo)) ? (a.id != -1) : (a.date_debut.Value <= dateTo))
&& ((String.IsNullOrEmpty(place)) ? (a.id != -1) : (a.emplacement.Contains(place)))
&& ((String.IsNullOrEmpty(state)) ? (a.id != -1) : (a.cd_prov == state))
&& ((String.IsNullOrEmpty(searchText)) ? (a.id != -1) : (a.libelle_activite.Contains(searchText)))
&& ((a.date_begin_display.HasValue ? DateTime.Now >= a.date_begin_display.Value : a.id != -1) &&
(a.date_end_display.HasValue ? DateTime.Now <= a.date_end_display.Value : a.id != -1))
&& (a.langue == "DUTCH" || a.langue == "B")).ToList<agenda>(); //GET DUTCH
}

You can add multiple where clauses:
var query = dc.agenda;
if(!String.IsNullOrEmpty(group))
query = query.Where(a => a.no_group == group)
if(!activityType.Equals("ALL"))
query = query.Where(a => a.type_manifestation == activityType)
// and so on for all your conditions...
if (Language == ConfBouwHelper.LanguageEnum.French)
query = query.Where(a => (a.langue == "FRENCH" || a.langue == "B"));
else
query = query.Where(a => (a.langue == "DUTCH" || a.langue == "B"));
listAgendaItems = query.ToList<agenda>();
This is a lot cleaner and readable and also solves the problem with the duplication because of the languages.