Here I am retrieving items and including the creator of the item. The goal is to include only the first and last name from the creator, not the entire user model.
var items = _db.Items.Include("Creator")
The item model has Creator as a navigation property like this:
public User Creator { get; set; }
It works fine, but it loads the entire user model, when really I just want the first name and last name.
How do I specify I only want specific property returned from the user model?
You cannot do that using Include. You can use Select instead:
var items = _db.Items.Select(i => new { Item = i, Creator = new { i.Creator.FirstName, i.Creator.LastName } });
Update
If you need to return that query as method result you have to create a class which could hold the results:
public class ItemWithCreatorNames
{
public Item Item { get; set; }
public string CreatorFirstName { get; set; }
public string CreatorLastName { get; set; }
}
var items = _db.Items.Select(i => new ItemWithCreatorNames { Item = i, CreatorFirstName = i.Creator.FirstName, CreatorLastName = i.Creator.LastName });
Related
My model looks like this
public partial class EditModel
{
public int Id { get; set; }
...
public string Item { get; set; }
}
My SearchItems method header looks like this
protected async Task<IEnumerable<ListItem>> SearchItems(string value)
which returns 'list' of these
public partial class ListItem
{
public string Id { get; set; }
public string Name { get; set; }
}
How do I get my MudAutocomplete to show the Name, yet return/bind the Id?
<MudAutocomplete T="ListItem" Label="Select item" #bind-Value="EditModel.Item"
Clearable="true"
MinCharacters="4" SearchFunc="#SearchItems"
ToStringFunc="#(i => i==null ? null : $"{i.Id} [{i.Name}]")"
SelectValueOnTab="true"/>
on the #bind-Value, Visual studio shows this error
...cannot convert from 'string' to 'EditModel.Item'
This is how I solved it for now...
My SearchItems method now just returns a list of string
protected async Task<IEnumerable<string>> SearchItems(string value)
I've put this attribute in the MudAutocomplete
ToStringFunc="#(i => ItemDisplay(i))"
This is my ItemDisplay method
private string ItemDisplay(string itemId)
{
var item = ListItems.FirstOrDefault(i => i.Id == itemId);
return item == null ? "!Not Found!" : $"{item.Id} [{item.Name}]";
}
I've had to add this to my ComponentBase, to 'cache' all the ListItems for use in ItemDisplay() method:
public List<ListItem> ListItems { get; set; } = new();
In OnInitializedAsync()
ListItems = await MyService.GetItemsAsync();
I've set up my GetItemsAsync() to use IMemoryCache (Microsoft.Extensions.Caching.Memory), but I still don't like this approach. I find it difficult to believe that this component does not support the feature.
Maybe the component is updated but I was able to achieve this by using the following approach which I think is good.
The model you want to use
record State(Guid Id, string Name);
The binding value
private State value1;
The search function returns IEnumerable<State>
private async Task<IEnumerable<State>> Filter(string value)
{
// Filtering logic
}
Finally, I am using ToStringFunc to define how values are displayed in the drop-down list
<MudAutocomplete T="State" ToStringFunc="#(state => state.Name)" Label="US States" #bind-Value="value1" SearchFunc="#Filter" Variant="Variant.Outlined"/>
I am stuck with this problem.
I have a model AssessmentModel defined like this:
public class AssessmentModel
{
public Respondent Respondent { get; set; }
public List<CompetencyModel> Competencies { get; set; }
}
public class CompetencyModel
{
public int Id { get; set; }
public string Name { get; set; }
public List<ResultModel> Results { get; set; }
}
public class ResultModel
{
public int Id { get; set; }
public int Score { get; set; }
}
All I need is to set value to the Score property of ResultModel.
Score is the only editable property here.
And I have just 1 View only, this view has a #model List, it displays a list of CompetencyModel items with Edit button for each one.
When I click the Edit button, the Id of CompetencyModel is passed to the same View, and the View draws an Edit form for ResultModel items that belong to the selected CompetencyModel.
However the form for ResultModel items exists on the same View, and the model of the View is still #model List.
How can I get to the Score property by using bindable Html.EditorFor(m=>m.Score) helper for each ResultModel item?
The View is defined like this:
#model List<CompetencyModel>
#foreach(var comp in Model)
{
<p>#comp.Name</p>
Edit
}
In the controller I set ViewBag.CurrentId = comp.Id, and at the bottom of the View:
if(ViewBag.CurrentId != null) //draw a form for ResultModel items
{
// What should I do now?
// how cant I use Html.EditorFor(m=>...) if the Model is still List<CompetencyModel>
}
I need to get to a single ResultModel entity to set a value to a Score property.
Thank you.
You should be able to get this done using Linq. Consider having the following code segment in the your last if statement
var result = Model.Results.FirstOrDefault(r => r.Id == ViewBag.CurrentId);
I dont have a IDE with me, so watchout for syntext errors
I am teaching myself asp .net mvc3. I have researched a lot but the more I read the more confused I become. I want to create a page where users can register their property for sale or rent.
I have created a database which looks like this:
public class Property
{
public int PropertyId { get; set; }
public int PropertyType { get; set; }
ยทยทยท
public int Furnished { get; set; }
...
}
Now, I want dropdownlistfor = PropertyType and Furnished.
Property type would be
1 Flat
2 House
3 Detached House
...
Furnished would be:
1 Furnished
2 UnFurnished
3 PartFurnished
...
Now, I am really not sure where to keep this information in my code. Should I have 2 tables in my database which store this lookup? Or should I have 1 table which has all lookups? Or should I just keep this information in the model?
How will the model bind to PropertyType and Furnished in the Property entity?
Thanks!
By storing property types and furnished types in the database, you could enforce data integrity with a foreign key, rather than just storing an integer id, so I would definitely recommend this.
It also means it is future proofed for if you want to add new types. I know the values don't change often/will never change but if you wanted to add bungalow/maisonette in the future you don't have to rebuild and deploy your project, you can simply add a new row in the database.
In terms of how this would work, I'd recommend using a ViewModel that gets passed to the view, rather than passing the database model directly. That way you separate your database model from the view, and the view only sees what it needs to. It also means your drop down lists etc are strongly typed and are directly in your view model rather than just thrown into the ViewBag. Your view model could look like:
public class PropertyViewModel
{
public int PropertyId { get; set; }
public int PropertyType { get; set; }
public IEnumerable<SelectListItem> PropertyTypes { get; set; }
public int Furnished { get; set; }
public IEnumerable<SelectListItem> FurnishedTypes { get; set; }
}
So then your controller action would look like:
public class PropertiesController : Controller
{
[HttpGet]
public ViewResult Edit(int id)
{
Property property = db.Properties.Single(p => p.Id == id);
PropertyViewModel viewModel = new PropertyViewModel
{
PropertyId = property.Id,
PropertyType = property.PropertyType,
PropertyTypes = from p in db.PropertyTypes
orderby p.TypeName
select new SelectListItem
{
Text = p.TypeName,
Value = g.PropertyTypeId.ToString()
}
Furnished = property.Furnished,
FurnishedTypes = from p in db.FurnishedTypes
orderby p.TypeName
select new SelectListItem
{
Text = p.TypeName,
Value = g.FurnishedTypeId.ToString()
}
};
return View();
}
[HttpGet]
public ViewResult Edit(int id, PropertyViewModel propertyViewModel)
{
if(ModelState.IsValid)
{
// TODO: Store stuff in the database here
}
// TODO: Repopulate the view model drop lists here e.g.:
propertyViewModel.FurnishedTypes = from p in db.FurnishedTypes
orderby p.TypeName
select new SelectListItem
{
Text = p.TypeName,
Value = g.FurnishedTypeId.ToString()
};
return View(propertyViewModel);
}
}
And your view would have things like:
#Html.LabelFor(m => m.PropertyType)
#Html.DropDownListFor(m => m.PropertyType, Model.PropertyTypes)
I usually handle this sort of situation by using an enumeration in code:
public enum PropertyType {
Flat = 1,
House = 2,
Detached House = 3
}
Then in your view:
<select>
#foreach(var val in Enum.GetNames(typeof(PropertyType)){
<option>val</option>
}
</select>
You can set the id of the option equal to the value of each item in the enum, and pass it to the controller.
EDIT: To directly answer your questions:
You can store them as lookups in the db, but for small unlikely to change things, I usually just use an enum, and save a round trip.
Also look at this approach, as it looks better than mine:
Converting HTML.EditorFor into a drop down (html.dropdownfor?)
I have two classes as follows
public class ODCTE_Major
{
public int ODCTE_MajorId { get; set; }
public string OfficialMajorName { get; set; }
public string MajorCode { get; set; }
... More unrelated code ....
}
AND
public class CareerMajor
{
...lots of unrealted code to this question left out
public int ODCTE_MajorId { get; set; }
public virtual ODCTE_Major ODCTE_Major { get; set; }
}
I added a controller with CRUD methods and in the create.cshtml there is this line
<div class="editor-field">
#Html.DropDownList("ODCTE_MajorId", String.Empty)
#Html.ValidationMessageFor(model => model.ODCTE_MajorId)
</div>
The select list populates it with the OfficialMajorName from ODCTE_Major. I need the select list to populate with the MajorCode or a value that looks like MajorCode - OfficialMajorName.
Could someone provide assistance for how this is done, please?
Thanks.
Add this to ODCTE_Major:
public string MajorDisplayName
{
get { return string.Format("{0} - {1}", MajorCode, OfficialMajorName); }
}
This is just a read only property used to create the display text in the format you want the menu to use.
Then in CareerMajor, add:
public IEnumerable<ODCTE_Major> Majors{ set; get; } // Thank you Shyju!
This will give you a place in your view model to pass the list of Majors you want in your menu to the view.
Then in your action method when you're creating a CareerMajor view model to send to the view, populate the new IEnumberable with the ODCTE_Major entities you'd like displayed in your menu.
On the view page:
#Html.DropDownListFor(m => m.ODCTE_MajorId, new SelectList(Model.Majors, "ODCTE_MajorId", "MajorDisplayName", Model.ODCTE_MajorId), "Select One")
This creates a SelectList to populate the drop down with. The SelectList constructor is saying use ODCTE_MajorId as the value for a SelectListItem in the menu, and to use MajorDisplayName as the text to actually display in the menu. It sets the selected value, if there is one, and adds a null item with the text "Select One" to the top of the menu. Feel free to take that final argument out if you don't want the null text.
Have your ViewModel hold a Collection property to represent all available Majors (for poulating the Dropdown)
public class CareerMajor
{
//other proiperties
public int ODCTE_MajorId { get; set; }
public IEnumerable<ODCTE_Major> Majors{ set; get; }
}
And in your GET Action, fill it and send it to your strongly typed view
pubilc ACtionResult Create()
{
var viewModel=new CareerMajor();
viewModel.Majors=db.GetllAllMajors(); // getting a list of ODCTE_Major objects
return View(viewModel);
}
and in the View, use the DropDownListFor HTML Helper method.
#model CareerMajor
#Html.BeginForm())
{
#Html.DropDownListFor(m=>m.ODCTE_MajorId,
new SelectList(Model.Majors,"ODCTE_MajorId ","MajorCode"),"select one..")
//other elements
}
In your controller action:
ViewBag.ODCTE_MajorId = new SelectList(availableMajors, "ODCTE_MajorId", "MajorCode");
*second and third parameters are the names of the value and text fields respectively
Then in your view:
#Html.DropDownList("ODCTE_MajorId", String.Empty)
where availableMajors is an IEnumerable that contains the majors you want to list.
I've got some data in a table that looks like so:
Recipe | Category | Email
What I'd like to do is pull this data back from the source and put it into something that looks like so:
public class RecipeItem
{
public long Recipe { get; set; }
public long Category { get; set; }
public List<string> Names {get; set; }
}
Grouping by the Recipe and Category ids and putting all the emails that into the list.
So, what I've tried is to do something like this:
var recipeItems =
from entry in list
group entry by new { entry.Recipe, entry.Category}
into aRecipe
select new RecipeItem()
{
Recipe = aRecipe.Key.Recipe,
Category = aRecipe.Key.Category,
// ? Not sure how to stick the list of names in here
};
list is the data pulled back via entity framework.
But this isn't quite right - I think I'm close here (maybe). What am I missing here on this?
Follow-up:
Thanks to Aducci for clearing this up. The answer is that you can do this:
Names = aRecipe.Select(x => x.Name)
and this will add all those Names which are in each group into the Names collection for that group. Pretty nifty.
I would modify your class to look like this
public class RecipeItem
{
public long Recipe { get; set; }
public long Category { get; set; }
public IEnumerable<string> Names {get; set; }
}
And your link to entities query to:
var recipeItems =
from entry in list
group entry by new { entry.Recipe, entry.Category}
into aRecipe
select new RecipeItem()
{
Recipe = aRecipe.Key.Recipe,
Category = aRecipe.Key.Category,
Names = aRecipe.Select(x => x.Name)
};