I have a SelectList in my MVC2 model.
In the case that there's only 1 item in the SelectList I want this one item automatically selected (in my view I add an additional item).
My problem is that I can't get this single item to be selected.
So the class behind my model has
if (Clients.Count() == 1)
{
Clients.First().Selected = true;
}
But immediately after stepping through this line, if I add a watch to Clients I can see that Selected = null.
In addition, on my View I have
<%:Html.DropDownListFor(c => c.Client, Model.Clients, "-- Select Client --") %>
When the page loads -- Select Client -- is always selected.
Can anyone explain how I can get the model to correctly mark the item as being selected?
Your view model must have a property Model.Client and it would appear (from the code above) that you're not setting that value?
Perhaps in the controller action:
Model.Client = Clients.First();
It's the Model.Client property you need to set though, not the SelectList options.
Related
Hypothetical:
Say i'm having someone order a cake and they choose vanilla or chocolate, and then they have to choose a frosting
if vanilla: strawberry or buttercream
if chocolate: mocha, dark chocolate or buttercream.
Right now the frosting value in the data model can accept all four options, so all four show up in the dropdown.
a) is there a way to change the binding for the second dropdown after the first is chosen?
This can be done without having the data saved in any datasource. Simply do the following...
Suppose the first dropdown is named primaryDropdown and the second dropdown is called secondaryDropdown. In the primaryDropdown options set the following:
["Vanilla", "Chocolate"]
Also, make sure to uncheck the option allowNull and on the onAttach event handler, place the following:
widget.value = "Vanilla";
Now we move on to the secondaryDropdown. Here, we will do a binding so place the following in the options value:
getAvailableOpts(#widget.root.descendants.primaryDropdown.value)
In the client script, we need to make sure that function exists so please paste the following in any client script:
function getAvailableOpts(primaryValue){
var options;
switch(primaryValue){
case "Vanilla":
options =["Strawberry","Buttercream"];
break;
case "Chocolate":
options = ["Mocha","Dark Chocolate","Buttercream"];
break;
default:
options = [];
}
return options;
}
From here, you are good; However we can still make it better. For that, make sure to also uncheck the allowNull option for the secondaryDropdown and then we need to add some logic in the onValueChange event handler of the primaryDropdown.
widget.root.descendants.secondaryDropdown.value = widget.root.descendants.secondaryDropdown.options[0];
References:
https://developers.google.com/appmaker/ui/input-widgets#dropdown
https://developers.google.com/appmaker/ui/binding#bindings
https://developers.google.com/appmaker/scripting/client#use_scripts_in_binding_expressions
Im guessing you set the dropdown "possible value" options in the data source and you have those fields as just string fields in your table.
the quick and dirty way to do this is go to the Cake drop down and on the Property Editor>Events>OnValueChange select Custom Action and use this Code
if(widget.value==="Vanilla"){
widget.root.descendants.Field.options = ['Strawberry','Buttercream'];
}else if (widget.value === "Chocolate"){
widget.root.descendants.Field.options = ['Mocha','Dark Chocolate','Buttercream'];
}
"Field" here is replaced with the name of the dropdown box for your frostings
also go to the property editor of the frostings dropdown and delete everything in the options field there.
I was trying to solve for a similar situation and created an additional table to serve as a lookup.
I have a drop down for CATEGORY with possible options set on the field in the main data source.
Then I have a second table with 2 Columns: CATEGORY, and SUB_CATEGORY.
On the entry form I have options for the SUB_CATEGORY drop down set to SUB_CATEGORY on the CATEGORY_MATRIX lookup table.
Then for an onValueEdit event on the CATEOGRY drop down I have a script to reload the CATEGORY_MATRIX table source based on the value of the CATEGORY drop down in the query so when the CATEGORY is selected only valid SUB_CATEGORY options are shown in the second drop down.
var datasource = app.datasources.CATEGORY_MATRIX
datasource.query.filters.CATEGORY._equals = newValue;
datasource.load();
There may be more efficient ways to do this but the benefit is I could create another form page and dynamically add new combos so there isn't any required code change as new combos are needed.
See Datasource Paging Issue (Revised)
for the original question.
Markus, you were kind enough to help with out with the issue of incorporating a record count into a query using a calculated datasource. I have a search form with 15 widgets - a mix of date ranges, dropdowns, text values and ._contains, ._equals, ._greaterThanOrEquals, ._lessThanOrEquals, etc.
I have tested this extensively against mySQL SQL code and it works fine.
I have now added a 16th parameter PropertyNames, which is a list with binding #datasource.query.filters.Property.PropertyName._in and Options blank. The widget on the form is hidden because it is only used for additional filtering.
Logic such as the following is used, such that a particular logged-in user can only view their own properties. So if they perform a search and the Property is not specified we do:-
if (params.param_Property === null && canViewAllRecords === false) {
console.log(params.param_PropertyNames); // correct output
ds.filters.Property.PropertyName._in = params.param_PropertyNames;
}
The record count (records.length) is correct, and if I for loop through the array of records the record set is correct.
However, on the results page the table displays a larger resultset which omits the PropertyNames filter. So if I was to search on Status 'Open' (mySQL results 50) and then I add a single value ['Property Name London SW45'] for params.param_PropertyNames the record count is 6, the records array is 6 but the datasource display is 50. So the datasource is not filtering on the property array.
Initially I tried without adding the additional parameter and form widget and just using code such as
if (params.param_Property === null && canViewAllRecords === false) {
console.log(params.param_PropertyNames); // correct output
ds.filters.Property.PropertyName._in = properties; // an array of
properties to filter out
}
But this didn't work, hence the idea of adding a form widget and an additional parameter to the calculated recordcount datasource.
If I inspect at query.parameters then I see:-
"param_Status": "Open",
"param_PropertyNames": ["Property Name London SW45"],
If I inspect query.filters:-
name=param_Status, value=Open
name=param_PropertyNames, value=[]}]}
It looks as though the filter isn't set. Even hard coding
ds.filters.Property.PropertyName._in = ['Property Name London SW45'],
I get the same reuslt.
Have you got any idea what would be causing this issue and what I can do for a workaround ?
Using a server side solution I would suggest editing both your SQL datasource query script (server side) that is supposed to filter by this property list and including the same code in your server side script for your calculated Count datasource. The code would look something like this, not knowing your exact details:
var subquery = app.models.Directory.newQuery();
subquery.filters.PrimaryEmail._equals = Session.getActiveUser().getEmail();
subquery.prefetch.Property._add();
var results = subquery.run();
if(!results[0].CanViewAllRecords) {
query.filters.Property.PropertyName._in = results[0].Property.map(function(i) {return i.PropertyName;});
}
By adding this code you are filtering your directory by your current user and prefetching the Property relation table, then you set the filter only if your user canviewallRecords is false and use JS map function to create an array of the PropertyName field in the Property table. As I stated, your code may not be exactly the same depending on how you have to retrieve your user canviewallrecords property and then of course I don't know your relation between user and Property table either, is it one-to-many or other. But this should give you an idea how to implement this on server side.
The following code in a cshtml file creates a dropdown with a list of Contacts, but the field it uses for the description of values, is not the one I want to display.
How do I force it to choose data from a different field in the Contact object?
#Html.DropDownList("ContactId", String.Empty)
#Html.DropDownListFor(a => a.OtherContactId,
new SelectList(Model.ContactList, "ContactId", "ContactValue",
Model.OtherContactId), "-- Select --")
where, Model.ContactList is populated in your controller action.
p.s. I'm not entirely certain whether you mean change the title of the select option text or the property that is updated, so have presented a kind of hybrid offering
You can try something like this on the server side(controller):
ViewBag.ContactList = new SelectList(iContactRepository.GetAllContacts(),
"ContactId", "Name", contactDefault.ContactId);
//Here the method GetAllContacts returns Iqueryable<Contact>.
And this on the view:
#Html.DropDownList("ContactIdSelect", ViewBag.ContactList as SelectList)
This is the SelectList documentation.
Hope it helps.
Can these two properties of a dropdown list in ASP.NET be used independently?
I wanted to retrieve a null value when the user selects some text; I couldn't as it retrieves the Text property whenever the Value is null. Eg:
l1 = new ListItem("Cat", null);
Console.WriteLine(l1.Value);
The output is
Cat
In another situation, when both the properties have different strings, I get the string in the Value property when I use the Text property. Eg:
l2 = new ListItem("Cat", "Mouse");
DropDownList ddl = new DropDownList();
ddl.Items.Add(li);
ddl.SelectedIndex = 0;
Console.WriteLine(ddl.SelectedValue);
Console.WriteLine(ddl.Text);
The output is
Mouse
Mouse
Your observation is correct. Contrary to what intuition tells us, ListControl.Text (and, thus, DropDownList.Text) does not return the Text property of the currently selected ListItem. Here's an excerpt from the documentation:
ListControl.Text Property
Gets or sets the SelectedValue property of the ListControl control.
[...]
Remarks
The Text property gets and sets the same value that the SelectedValue property does.
To get the Text property of the selected ListItem, use SelectedItem to retrieve the currently selected list item and then access the Text property.
So, the behavior you are seeing is by design. Why did the .NET developers specify ListControl.Text in such an unintuitive way? I have no idea. Maybe it was necessary to support the ITextControl interface...
Just set the value to some sentinel value like an empty string or some crazy string "JANDKJASD_" and handle it accordingly.
I have a dropdown list (FK) which I would like to set and display a default value based on a login userid. Can you please tell me how to do it? I only want to affect the dropdown filter that appear at the top above the Gridview.
Thanks
Nikos
If you only want this functionality in the DropDown list that appears in the Filter Criteria section, just modify the URL by adding the QueryString parameters you would like to filter by. The DynamicFilter will pick up the values from the QueryString and set the DropDown lists accordingly. (fyi. this is the same functionality that the ForeignKey.ascx FieldTemplate provides)
It would be nice if there was a better way to actually create this URL (instead of using string), but as of right now, any solution I provide is probably going to break in a subsequent version.
example (in page_load)
Response.Redirect("~/Employees/List.aspx?ReportsTo=1234");
Is this a universal change, or just for one foreign key relationship?
Assuming it is for just one foreign key relationship, you could create a new FieldTemplate, to be used just for that relationship. The New FieldTemplate would be a copy of the default "ForeignKey" FieldTemplate. In the New FieldTemplate modify the OnDataBinding (or Page_PreRender) event to set the "default value" of the DropDownList.
Then, to force the New FieldTemplate to be used for that relationship, you would need to use the System.ComponentModel.DataAnnotations.UIHint attribute on the member of your Entity Class that represents that foreign key relationship. (links below)
http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.uihintattribute.uihint.aspx
or http://www.asp.net/learn/3.5-SP1/video-291.aspx (around 07:30 mins)
For a little help, you could take a look at the DynamicData Futures release on CodePlex. Specifically the "Populate Insert templates with values from filters" section. http://www.codeplex.com/aspnet/Release/ProjectReleases.aspx?ReleaseId=14475
I have figured out a workaround, but am open to a more elegant solution.
I edited the FilterUserControl.ascx.cs by inserting the following line in the Page_Init after PopulateListControl(DropDownList1);
DropDownList1.SelectedIndex = DropDownList1.Items.IndexOf(DropDownList1.Items.FindByText("Bob")); // Username is hardcoded just for test
This seems to work but I would prefer using the custom Partial Entity Class with metadata to solve this if possible.
I have solved this in an application I am working on, in your insert view template code behind:
In ItemCreated event for the details view:
foreach (DetailsViewRow row in DetailsView1.Rows)
{
foreach (Control ctl in row.Controls)
foreach (Control c in ctl.Controls)
foreach (Control x in c.Controls)
{
if (x.ClientID.Contains("tblName"))
{
foreach (Control y in x.Controls)
{
if (y.ClientID.Contains("DropDownList"))
{
ddl = y as DropDownList;
ddl.SelectedValue = Convert.ToString(UserId);
ddl.Enabled = false;
}
}
}
}
}
With this code, when a user is logged in and they go to insert some entity (tblName) the drop down list (fk to userId) is already selected and disabled.