I have Companies that I am attempting to filter down using criteria. Each Company has a CurrentStatus, and the method to filter is called everytime the user checks a CheckBox to define a filter. I currently have this working almost exactly how I want it, aside from one thing. This is what I have;
private void FilterCompanyType(object sender, RoutedEventArgs e)
{
criteria.Clear();
if (currentCheckBox.IsChecked == true)
{
criteria.Add(new Predicate<CompanyModel>(x => x.CurrentStatus == 1));
}
if (nonCurrentCheckBox.IsChecked == true)
{
criteria.Add(new Predicate<CompanyModel>(x => x.CurrentStatus == 0));
}
foreach (CheckBox checkBox in companyFilters.Children)
{
if (!CheckCheckBoxes())
{
dataGrid.ItemsSource = null;
compDetailsLabel.Content = string.Empty;
}
else
{
dataGrid.ItemsSource = CompanyICollectionView;
CompanyICollectionView.Filter = dynamic_Filter;
SetSelectedCompany(selectedIndex);
dataGrid.SelectedIndex = 0;
}
}
}
As I said this is working OK, it works for when the user wants to see a list of Companies where CurrentStaus == 1 OR a list of Companies where CurrentStatus == 0. However, currently the user cannot see a list of Companies, if both CheckBoxes are checked where CurrentStatus == 0 AND CurrentStatus == 1.
I have tried adding this but it does not work with both CheckBoxes checked;
if (nonCurrentCheckBox.IsChecked == true && currentCheckBox.IsChecked == true)
{
criteria.Add(new Predicate<CompanyModel>(x => x.CurrentStatus == 0));
criteria.Add(new Predicate<CompanyModel>(x => x.CurrentStatus == 1));
}
This just returns an empty DataGrid. How can I change the Predicate to allow for both?
If I clearly understand, if statements should look like this.
if ( currentCheckBox.IsChecked == true && nonCurrentCheckBox.IsChecked == false )
{
criteria.Add( new Predicate<CompanyModel>( x => x.CurrentStatus == 1 ) );
}
else if ( nonCurrentCheckBox.IsChecked == true && currentCheckBox.IsChecked == false )
{
criteria.Add( new Predicate<CompanyModel>( x => x.CurrentStatus == 0 ) );
}
else if ( nonCurrentCheckBox.IsChecked == true && currentCheckBox.IsChecked == true )
{
criteria.Add( new Predicate<CompanyModel>( x => ( x.CurrentStatus == 0 || x.CurrentStatus == 1 ) ) );
}
Related
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))
});
I am developing an Asp.Net MVC Application and i am new to Linq and CodeFirst. In my controller this is the action that i have written:
public ActionResult Filter(int? PaperType , int? PaperGram , int? Brand)
{
var FilteredResult ;
if (PaperType.HasValue && PaperGram.HasValue && Brand.HasValue) {
FilteredResult = db.Stocks.where(m => m.PaperType == PaperType && m.PaperGram == PaperGram && m.Brand == Brand);
}
else if (PaperType.HasValue && PaperGram.HasValue) {
FilteredResult = db.Stocks.where(m => m.PaperType == PaperType && m.PaperGram == PaperGram);
}
else if (PaperType.HasValue && Brand.HasValue) {
FilteredResult = db.Stocks.where(m => m.PaperType == PaperType && m.Brand == Brand);
}
// and ifs continue to last
/*
.
.
.
.
*/
else {
FilteredResult = db.Stocks;
}
return View(FilteredResult);
}
But i know that this is not the best way to do in Linq and Codefirst. So, can you give a better solution to this problem?
You can do this:
FilteredResult = db.Stocks.where(m => (m.PaperType == PaperType || !PaperType.HasValue)
&& (m.PaperGram == PaperGram || !PaperGram.HasValue)
&& (m.Brand == Brand || !Brand.HasValue));
What you want to avoid is code duplication.
Create your original IQueriable and then add your where clauses when necessary
public ActionResult Filter(int? PaperType, int? PaperGram, int? Brand)
{
var FilteredResult FilteredResult = db.Stocks.AsQueryable();
if(PaperType.HasValue)
{
FilteredResult = FilteredResult.where(m => m.PaperType == PaperType);
if(PaperGram.HasValue)
FilteredResult = FilteredResult.where(m => m.PaperGram == PaperGram );
if ( Brand.HasValue)
FilteredResult = FilteredResult.where(m => m.Brand == Brand);
}
return View(FilteredResult);
}
You can just assign all elements to list and then filter every element in each if condition
IEnumerable<Stock> filteredResult = db.Stocks.AsQueryable();
if (PaperType.HasValue)
{
filteredResult = filteredResult.Where(m => m.PaperType == PaperType);
}
if (PaperGram.HasValue)
{
filteredResult = filteredResult.Where(m => m.PaperGram== PaperGram);
}
if (Brand.HasValue)
{
filteredResult= filteredResult.Where(m => m.Brand== Brand);
}
return View(FilteredResult.ToList());
Simply put I was wondering if this is possible?
if (Descriptionsearch.Checked)
{
searchResult = searchResultBuilder(a.Description == textBox.Text))
}
else if (titleSearch.Checked)
{
searchReuslt = searchResultBuilder(a.title == textBox.Text))
}
As you can see I am simply sending a condition of a variable that has not yet been initialized but will be at the time of use.
private List<int> searchResultBuilder(Func<bool> condition)
{
foreach (var element in currentPosition.Where(a => condition()))
{
searchResults.Add(currentPosition.IndexOf(element));
}
return searchResults;
}
I simply wanted to know if there is a way to do this.
since people are asking this is the for loop from my original code
foreach(var element in main.currentPosition.Where(a => (a.key != null && main.msgSigCollection1.msgSig[(int)a.key].Description.IndexOf(searchTextBox.Text, StringComparison.OrdinalIgnoreCase) >= 0) || (a.value != null && main.msgSigCollection2.msgSig[(int)a.value].Description.IndexOf(searchTextBox.Text, StringComparison.OrdinalIgnoreCase) >= 0)))
{
searchResults.Add(main.currentPosition.IndexOf(element));
}
where currentPosition is a List<int?,int?>
You need to specify a lambda syntax to achieve what you want.
Ex: (input parameters) => expression
if(Descriptionsearch.checked == true)
searchReuslt = searchResultBuilder(a => a.Description == textBox.Text))
else if(titleSearch.checked == true)
searchReuslt = searchResultBuilder(a => a.title == textBox.Text))
MSDN
It's hard to tell based on your question, but I think what you want is to be passing lambdas, which is not what you're doing currently.
Something like this seems closer to what you want:
if(Descriptionsearch.checked == true)
searchReuslt = searchResultBuilder(a => a.Description == textBox.Text))
else if(titleSearch.checked == true)
searchReuslt = searchResultBuilder(a => a.title == textBox.Text))
private List<int> searchResultBuilder<T>(Func<T, bool> condition){
var searchResults = new List<int>();
foreach (var element in currentPosition.Where(condition))
{
searchResults.Add(currentPosition.IndexOf(element));
}
return searchResults;
}
In truth though, your question should state what you're trying to accomplish, not just how you're attempting to get there. There probably is a much easier way to accomplish everything you're trying to do here with LINQ.
I have following code in c# in which I am searching for lowest price flight .Now I want to convert it to Linq
for (; count < _flightSearchController.ListOfContracts.Count; count++)
{
contract = (DTContract)_flightSearchController.ListOfContracts[count];
if (contract.CurrentStatus == AvailabilityStatus.AVAILABLE)
{
if (CheckContractCitiesWithSearchCriteria(contract, originAirports, destinationAirports))
{
//if fare is lower than selected contract.
if (lowestPriceContract == null || lowestPriceContract.FareDetails.PriceForDefaultFlightSelection > contract.FareDetails.PriceForDefaultFlightSelection)
{
lowestPriceContract = contract;
}
else if (lowestPriceContract.FareDetails.PriceForDefaultFlightSelection == contract.FareDetails.PriceForDefaultFlightSelection)
{
if (lowestPriceContract.FareDetails.PriceAdult > 0 && (lowestPriceContract.FareDetails.PriceAdult + lowestPriceContract.FareDetails.FareTaxAdult) > (contract.FareDetails.PriceAdult + contract.FareDetails.FareTaxAdult))
{
lowestPriceContract = contract;
}
else if (lowestPriceContract.FareDetails.PriceSenior > 0 && (lowestPriceContract.FareDetails.PriceSenior + lowestPriceContract.FareDetails.FareTaxSenior) > (contract.FareDetails.PriceSenior + contract.FareDetails.FareTaxSenior))
{
lowestPriceContract = contract;
}
}
}
}
I tried it to convert but stuck in if else if section.
var q = _flightSearchController.ListOfContracts.ToList<DTContract>()
.Where(cont => cont.CurrentStatus == AvailabilityStatus.AVAILABLE);
if (lowestPriceContract == null || lowestPriceContract.FareDetails.PriceForDefaultFlightSelection > contract.FareDetails.PriceForDefaultFlightSelection)
{
}
Use the Min extension method:
var q = _flightSearchController.ListOfContracts
.Where(cont => cont.CurrentStatus == AvailabilityStatus.AVAILABLE
&& CheckContractCitiesWithSearchCriteria(cont, originAirports, destinationAirports))
.Min(cont=> cont.FareDetails.PriceForDefaultFlightSelection)
Edit I had glossed over the tie-breaker part, which makes it a bit more complicated. You can do it with sorting, but this will be slower when there are a lot of contracts:
var q = _flightSearchController.ListOfContracts
.Where(cont => cont.CurrentStatus == AvailabilityStatus.AVAILABLE)
&& CheckContractCitiesWithSearchCriteria(cont, originAirports, destinationAirports))
.OrderBy(cont => FareDetails.PriceForDefaultFlightSelection)
.ThenBy(cont => cont.FareDetails.PriceAdult + lowestPriceContract.FareDetails.FareTaxAdult)
.ThenBy(cont => cont.FareDetails.PriceSenior + lowestPriceContract.FareDetails.FareTaxSenior)
.First();
You could implement the IComparable interface for the FareDetails object to compare the prices, which would allow you to do this:
var q = _flightSearchController.ListOfContracts
.Where(cont => cont.CurrentStatus == AvailabilityStatus.AVAILABLE
&& CheckContractCitiesWithSearchCriteria(cont, originAirports, destinationAirports))
.Min(cont=> cont.FareDetails)
I am filtering a collection and I perform 2 filters that are the same but for different fields.
There must be a way I can reduce the duplication of code here?
The checks are whether a date has been entered, and whether it is before a cut off date entered by the user.
public override IList<Company> Search()
{
var list = CacheObjects.Subcontractors;
this.ApplicationFormReturnedCheck(ref list);
this.ApplicationFormSentCheck(ref list);
}
private void ApplicationFormReturnedCheck(ref IList<Subcontractor> list)
{
if (this.ApplicationFormNotReturnedFlag == true && this.ApplicationFormReturned != null)
{
list =
list.Where(x => x.ApplicationFormReturned == null || x.ApplicationFormReturned < this.ApplicationFormReturned).ToList();
}
else if (this.ApplicationFormNotReturnedFlag == true)
{
list = list.Where(x => x.ApplicationFormReturned == null).ToList();
}
else if (this.ApplicationFormReturned != null)
{
list = list.Where(x => x.ApplicationFormReturned < this.ApplicationFormReturned).ToList();
}
}
private void ApplicationFormSentCheck(ref IList<Subcontractor> list)
{
if (this.ApplicationFormNotSentFlag == true && this.ApplicationFormSent != null)
{
list =
list.Where(x => x.ApplicationFormSent == null || x.ApplicationFormSent < this.ApplicationFormSent).ToList();
}
else if (this.ApplicationFormNotSentFlag == true)
{
list = list.Where(x => x.ApplicationFormSent == null).ToList();
}
else if (this.ApplicationFormSent != null)
{
list = list.Where(x => x.ApplicationFormSent < this.ApplicationFormSent).ToList();
}
}
I would suggest you can do something as simple as have some instances of Func<Subcontractor,bool> which cover your various scenarios. This is the type of Func that the Where method expects
To demonstrate let me take one of your methods and show you how:
private void ApplicationFormReturnedCheck(ref IList<Subcontractor> list)
{
var isFormReturned = new Func<Subcontractor,bool>(
x => x.ApplicationFormReturned != null);
var isBeforeDate = new Func<Subcontractor,bool>(
x => x.ApplicationFormReturned < this.ApplicationFormReturned);
var isFormReturnedOrBeforeDate= new Func<Subcontractor,bool>(
x => isFormReturned(x) || isFormReturnedBeforeDate(x));
if (this.ApplicationFormNotReturnedFlag == true && this.ApplicationFormReturned != null)
{
list = list.Where(isFormReturnedOrBeforeDate).ToList();
}
else if (this.ApplicationFormNotReturnedFlag == true)
{
list = list.Where(isFormReturned).ToList();
}
else if (this.ApplicationFormReturned != null)
{
list = list.Where(isBeforeDate).ToList();
}
}
The other method you've shown, although having similar logic, uses a different set of variables. (ApplicationFormSent in place of ApplicationFormReturned). The way I see it you have two options
Duplicate the above within the other method, using the differing variable names
Use a more complex method whereby you have these 3 Func's outside of the scope of each method, and able to distinguish which variables (*Sent or *Returned) to use.
The problem with 2. above is that as your perceved "reuse" goes up, the readability of your code goes down.
In all honesty, I see no major problem with your original code! Its clear, its pretty concise and its easy to see what it's doing. By wrapping all this logic up with predicates (which could conceivably be elsewhere in the class), you're making it harder to read and harder to maintain.
A Func(T, TResult) can be used to encapsulate common predicate methods. In your case, the Func would need to be initilialized in the constructor since you are using instance members in the filter. Ex:
private readonly Func<Subcontractor, bool> _pred;
public Subcontractor()
{
_pred = x => x.ApplicationFormReturned == null || x.ApplicationFormReturned < this.ApplicationFormReturned;
}
private void ApplicationFormReturnedCheck( ref IList<Subcontractor> list )
{
if( this.ApplicationFormNotReturnedFlag == true && this.ApplicationFormReturned != null )
{
list = list.Where( _pred ).ToList();
}
else if( this.ApplicationFormNotReturnedFlag == true )
{
list = list.Where( x => x.ApplicationFormReturned == null ).ToList();
}
else if( this.ApplicationFormReturned != null )
{
list = list.Where( x => x.ApplicationFormReturned < this.ApplicationFormReturned ).ToList();
}
}