I'm trying to set an accessibilityValue property in swift application.
It doesn't work , while I'm trying to inspect the element with appium , the actual value is different from the value I've tried to set.
In case and I'm setting next values :
self?.isAccessibilityElement = true
self?.accessibilityLabel = "Header"
self?.accessibilityValue = Some dynamic value
The value property is being override by the accessibilityLabel value
Any idea what has gone wrong ?
Thanks
Related
I'm setting the Placeholder value of a EntryView() in my application to a value I'm retrieving from my database. But now I want to change my approach and instead set the value of the EntryView so that the user does not have to fill in the content.
This is my code to retrieve the value and then set the Placeholder:
let firstName = dict["firstName"] as? String
...
self.firstNameEntryView.setPlaceholder(firstName!)
This functionality works fine and it populates the correct value as the placeholder. But how do I make the String value of 'firstName' be set as the actual value in my firstNameEntryView?
I tried this approach:
self.firstNameEntryView.setValue(String?.self, forKey: firstName!)
But I get this error: " setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key Thomas"
Thomas is the correct value from my db. Am I using the setValue method incorrectly?
I ended up figuring this out through trial and error.
The code to set the text is as follows:
self.firstNameEntryView.textField.text?.append(firstName!)
Let's started with the code snippet:
St Foo {
var proA: Int = 0 { // needs initialization
willSet {
print("about to set proA to \(newValue) from \(proA)")
}
didSet {
print("already set proA to \(proA) from \(oldValue)")
}
}
var ProB: Int { // do not needs initialization
return 1
}
}
let foo = Foo()
foo.proA = 23
print(foo.ProB)
Here are some of my personal understandings about the the stored and computed property:
a: Property with only the observer (willSet and didSet) is not a computed property but a stored property (ex. the proA property in the code above).
b: Computed property must not has initialization (See the comments of the code above).
c: setter is kind of equal to the property observer, the property observer is just the setter + the observer to of the before and after mutating.
Questions:
1. I wonder what makes a property a computed property? Is it correct that as long as the property has a getter and return it is a computed property?
2. Are all my understandings (a, b & c) correct? If not, would be nice of you to point out.
3. Why is it not allowed to initialize an computed property? (Please see the figure below) And when I do so the compiler gives out the warning Cannot call value of none-function type "int" What's the meaning of this error?
Thanks a lot.
First, this is about variables, not properties. Any variable can be a computed variable. A property is just one way to use a variable.
I think on the whole you are making a big mistake in putting a stored variable with setter observers side by side with a computed variable. They are unrelated!
Think of a computed variable as something that looks and acts like a variable when you use it — you get and (maybe) set it — but is in fact a function (or a pair of functions). It is just a compact way of calling a function. That's all it is.
A stored variable with observers, on the other hand, is just a stored variable that also has some observers.
Okay, on to your questions:
I wonder what makes a property a computed property? Is is correct that as long as the property has a getter and return it is a computed property?
Yes. It's a computed variable because you declared it using the syntax that makes it a computed variable (with the curly braces).
Are all my understandings (a, b & c) correct? If not would be nice of you to point out
Yes. I think your "c" is quite insightful: a computed variable does not need a setter observer because it has (gasp!) a setter!
Why is it not allowed to initialize an computed property? (Please see the figure below) And when I do so the compiler gives out the warning Cannot call value of none-function type "int" What's the meaning of this error?
There is no sense in which a computed variable "has" a value — it is computed! it's just some functions! — so it makes no sense to assign it an "initial" value.
A stored property is a property of which the property value is stored together with the instance of the class or struct. The value may be changed, but the property can also be a constant. Thus a stored property can be as simple as:
var proA: Int
let proB: Int
var proC: Int = 0
Computed properties do not store a value. Thus you cannot assign a value to a computed property. A Computed property should have a getter that returns a value. I a broad term, you can think of a computed property as a property that returns the value of a function.
Example of Computed Property
var proA: Int {
return proB * proC
}
With regards to your questions:
Computed Property is therefor a property that do not store a value, and contains a get to return the 'computed' value of the property.
a is correct, b computed properties should not have initialization, c if you mean willSet and didSet. Yes they are like observers for when the property's value will change and did change respectively
Since the value of a computed property is not stored and will never be used, the compiler forbids it.
Hope this helps a bit.
I wonder what makes a property a computed property? Is is correct that as long as the property has a getter and return it is a computed property?
If you define get { } inside the property declaration, it makes that property to a computed property.
And it cannot have initial value as when you access the property, it will always call get{} function declared in property.
Are all my understandings (a, b & c) correct? If not would be nice of you to point out
a is correct
b is wrong.
You can not set initial value for computed property.
Because as I explained in question 1, it will always return result of get{} when you need access to the property.
c : 50% right
setter , it can also be used as to store newValue into another private variable and you can do some additional observing logic. So to observe value changes on stored property, you use willSet and didSet
You can define observing logic on computed property (which has getter and setter) on set{} declaration. But main purpose of set {} is to store the value to another variable or for example UserDefaults.
Why is it not allowed to initialize an computed property? (Please see the figure below) And when I do so the compiler gives out the warning Cannot call value of none-function type "int" What's the meaning of this error?
Same answer
Your code makes compiler to be confused
When you set initial value on the property on declaration, the compiler tries to understand it as stored property. But you also defined get{} for this property, and it means it is computed property and should always return 22 when you access the property. So you should remove one of two.
a. Yes,a property with only observer is a stored property not a computed property.Beacuase property observer tracks the value of a property whose value has initialised previously & it's now changing ,that's a stored property. It's not applicable for a computed property since it has no predefined value
b. computed property is a property whose value depends on other variables, we should declare only those properties as computed property , who needs to be computed using value of another variables ,so it's value cannot be initialised in advance.
for e.g. - If we have 2 variables a & b. we need their addition value , so a variable named 'sum' is used , then sum will be declared as a computed property & its get{} block will return (a+b) that's sum of a & b & the value of sum variable.Then in this case we can't initialise property 'sum'
in advance because it will be computed using a & b.
c. Setter is not an observer it sets value of another variable or performs some actions related to other variables whereas a property observer tracks changes in value of its associated variable itself. for e.g. it's meaningless to use a property observer for variable 'sum' as described in point b .
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
Is there a way of creating method for setting the value in the Model's fields without setting the values explicitly like -
ModelName.create.fieldName1("value").fieldName2("value2") and so on
Can we iterate through all available fields of that model and set their values form some list-of-values ?
something like ...
Model.allFields.foreach((fld)=> {
fld.set(valueList(indx)); indx+=1
}
Actually I want to set values into all models using some generic method that works for all models.
According to my comment:
val list = List(...)
val record = YourRecordClass.createRecord
record.allFields.zip(list).foreach {case(field,value) => field.setFromAny(value)}
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.