I have a dropdownlist box, from which a user makes a selection.
However, I am not able to retrieve the value of the SelectedItem in the code behind.
How can I get the value selected in the code behind?
if (ddlRegion.SelectedValue = "0")
{
Response.Write("<script>window.alert('Please select a region')</script>");
txtEmpID.Text = "";
return;
}
It looks like you're trying to compare to 0, are you trying to check if the dropdownlist is at its default state (which is the first value)? If so, SelectedIndex is the property you want, and you want to compare to the integer literal 0, not the string "0". Also, it's probably a copy/paste error as it doesn't compile as is, but you want to compare equality with ==, not make an assignment with =.
try SelectedValue property of dropdownlist instead of SelectedItem
(SelectedValue from MSDN) This
property returns the Value property
of the selected ListItem. The
SelectedValue property is commonly
used to determine the value of the
selected item in the list control. If
multiple items are selected, the value
of the selected item with the lowest
index is returned. If no item is
selected, an empty string ("") is
returned.
I'd go with the answer "Tanzelax" proposed, but none-the-less, you're comparing against "0" and the Microsoft documentation is telling you to compare against an empty string.
Related
With arrays you can use a subscript to access Array Elements directly. You can read or write to them. With Sets I am not sure of a way to write its Elements.
For example, if I access a set element matching a condition I'm only able to read the element. It is passed by copy and I can't therefore write to the original.
For example:
columns.first(
where: {
$0.header.last == Character(String(i))
}
)?.cells.append(value: addValue)
// ERROR: Cannot use mutating member on immutable value: function call returns immutable value
You can't just change things inside a set, because of how a (hash) set works. Changing them would possibly change their hash value, making the set into an invalid state.
Therefore, you would have to take the thing you want to change out of the set, change it, then put it back.
if var thing = columns.first(
where: {
$0.header.last == Character(String(i))
}) {
columns.remove(thing)
thing.cells.append(value: addValue)
columns.insert(thing)
}
If the == operator on Column doesn't care about cells (i.e. adding cells to a column doesn't suddenly make two originally equal columns unequal and vice versa), then you could use update instead:
if var thing = columns.first(
where: {
$0.header.last == Character(String(i))
}) {
thing.cells.append(value: addValue)
columns.update(thing)
}
As you can see, it's quite a lot of work, so maybe sets aren't a suitable data structure to use in this situation. Have you considered using an array instead? :)
private var _columns: [Column]
public var columns : [Column] {
get { _columns }
set { _columns = Array(Set(newValue)) }
// or any other way to remove duplicate as described here: https://stackoverflow.com/questions/25738817/removing-duplicate-elements-from-an-array-in-swift
}
You are getting the error because columns might be a set of struct. So columns.first will give you an immutable value. If you were to use a class, you will get a mutable result from columns.first and your code will work as expected.
Otherwise, you will have to do as explained by #Sweeper in his answer.
I have created a multifield custom widget having two fields with names ./urlLink and ./urlText.
Now i m trying to fetch the values from widget into the component's jsp with following code
String property = properties.get("./urlLink",String[].class);
for(String value: property ) {
out.print(value);
}
out.print(property);
But i am not able to get its value instead i m getting error.
If you're getting a property and it contains a string value, you need to use the method getString() - that way when you have the property, you can set the string to the value by doing something like this:
Property property = properties.get("./urlLink",String.class);
String value = property.getString();
Just a side note, if your return is supposed to be a string array, your type that you're putting the values in should be a string array.
String[] value
Check out the documentation on day.com for Properties and getting the values inside them.
Looks like a typo: you don't prefix a property name with .\ when accessing it.
My guess is you got a NullPointerException, right? That's because there's no ./urlLink property in the value map (properties). You should check against that anyway (so that it's not thrown on a fresh page with no content).
If that doesn't help -- double check that you have the properties in the content (call your page with .xml or .infinite.json extensions, and then double check if you can read them as plain strings (you should be able to -- CRX does some magic, smart type conversions).
It's good to register custom xtype as :
// registering the custom widget with the name dualfield
CQ.Ext.reg("dualfield", CQ.Ext.form.DualField);
Then u can easily fetch the value as :
String[] data = properties.get("multi",String[].class);
Here multi is the name of widget having multifield as xtype
I am using rich faces select component.
I want dynamic values when user manually type some thing in the select component.
<rich:select enableManualInput="true" defaultLabel="start typing for select" value="#{supplierSearchBean.userInput}">
<a4j:ajax event="keyup" execute="#this" listener="#{supplierSearchBean.userInputChange}"/>
<f:selectItems value="#{supplierSearchBean.selectOptions}" />
</rich:select>
Java code as follows
public void userInputChange(ActionEvent ae){
Map map = ae.getComponent().getAttributes();
System.out.println(map.toString());
}
public void setUserInput(String userInput) {
System.out.println("userINput = " + userInput);
this.userInput = userInput;
}
Here i found 2 issues
1st: setUserINput always print empty string when user type value
2nd: listener method never get call.
any help ?
The problem is most probably that there is no selected value while the user types, and this component restricts the allowed values to the specified select items. A partial input is thus not valid and cannot be bound to your bean.
I think you could get the expected behavior if you use a rich:autocomplete instead. However, if you want to restrict the allowed values, maybe you can keep your rich:select and listen for the selectitem event.
Override getItems function in richfaces-utils.js file in richfaces-core-impl-4.0.0.Final.jar under richfaces-core-impl-4.0.0.Final\META-INF\resources folder.
Change the condition of pushing items to be
if(p != -1)
instead of
if(p == 0)
This should fix the issue.
I'm working on single page application, which involves sorting.
I use
viewModel = new {
SortAsc = ko.observable(true)
};
ko.linkObservableToUrl(viewModel.SortAsc, "Asc", viewModel.SortAsc());
to achieve that mapping. And it works, but the problem is that mapping returns literal strings "false" and "true" instead of bool value. This causes a problem with checkbox, which is bound to that property:
<input type="checkbox" data-bind="checked: SortAsc" value="Ascending"/>
The question is, how can I make that value from url to be converted to correct type (normal bool), so my checkbox will be updated properly?
Ok, I found how to overcome that problem. Not very elegant, but works.
1. I assumed, that SortAsc will be a string property in my logic. So I left it bound to url like in the question text. Only initialized it with string, istead of bool ("true" intead of true).
2. I created writeable dependend observable, which will do the convertion:
viewModel.SortAscBool = ko.dependentObservable({
read: function () {
return this.SortAsc() === "true";
},
write: function (value) {
this.SortAsc(String(value));
},
owner: viewModel
});
and bound my checkbox to that prop. So now, when checkbox is checked, SortAscBool is changed and it sets literal value to SortAsc (I think this convertion is really not needed, but as a C# programmer I like it that way :)). And of course, when SortAsc changes, SortAscBool will also change and return the converted value to checked binding. And that is what was really needed.
Also, my first though was to simply create one way dependend observable, but then url will not be updated with values from checkbox.
I've a collection of a class' properties and would like to update each one's value by iterating over the collection through the index.
1) I create the collection of properties this way
private PropertyInfo[] GetPropertiesOfMyClass()
{
Type myType = (typeof(myClass));
PropertyInfo[] PropertyInfoArray = myType.GetProperties(
BindingFlags.Public |
BindingFlags.Instance);
return PropertyInfoArray;
}
2)Now, I'd like to set up the value of each one depending on the index this way
public void UpdateProperty(MyClass instanceOfMyClass, string valueToUpdate, int index)
{
//TODO:
//1. Get an individual property from the GetPropertyOfMyClass() using index
//2. Update the value of an individual property of the instanceOfMyClass
}
I'd like to be able to call UpdateProperty from a Controller like this:
UpdateProperty(instanceOfMyClass, valueToUpdate, indexOfTheProperty);
Honestly, I do not know how to involve the instanceOfMyClass in the game as GetProperty only plays with myClass.
Since I saw that I can use Name, PropertyType, ... to get information on the property. So, I've tried also GetPropertyOfMyClass()[index].SetValue(...), but I was lost in the arguments of its constructor, so I abandoned.
What I want is to be able to update the value of a property in my collection just by using the index.
Thanks for helping
Your guess was correct. You use SetValue() to update the value - this is how to do it:
GetPropertyOfMyClass()[index].SetValue( instanceOfMyClass, valueToUpdate, null);
The last argument can be null:
Optional index values for indexed properties. This value should be null for non-indexed properties.