I have a query in my flutter app that should return empty if 'archived' 'isNull' is set to true. I accomplished that, but the issue I'm having now is the fact that the query returns empty (i.e [ ]). And on the widget, I want this to be shown as not having any value but instead, an empty pair of brackets '()' keep showing up.
I have tried checking for when query data equals null, something like this:
if (queryResult.data == null){
// The idea is for it not to just return '()' as the value
value = null;
}
else{
value = queryResult.data;
}
And also:
if (queryResult.data == []){
value = null;
}
else{
value = queryResult.data;
}
How do I go about this? Thanks in advance.
If "data" is a list why not try data.isEmpty() ? And also if you only need to avoid the brackets (dirty fix alert ⚠️) whatever you did it's returning a string value '()' then you check that
if(yourResults == '()' )value == null;
And please add more details for a better answer .
Related
Hello I try to make null safety migration, but have a probleme with
prefs.setStringList("save_list_autre2",save_list.toList());
the error is : the argument list<String?> can't be assigned to the parameter type List
RegExp regExp = new RegExp(r'(...)');
var save_list= regExp.allMatches(decrypted).map((z) => z.group(0));
if(regExp.allMatches(decrypted)==null ){
[...]
} else {
prefs.setStringList("save_list_autre2",save_list.toList());
}
I add .toString() from save_list= regExp.allMatches(decrypted).map((z) => z.group(0).toString());
the error is removed but I don't know if it's the good solution
When you call z.group(0) the group method could return null if there was no group with the given index (0 in this case). so dart thinks you might have some null values on your list of strings.
The reality is that you shouldn't get any null values because you are passing a 0. So to tell dart that the method isn't returning null, use the ! operator:
regExp.allMatches(decrypted)
.map((z) => z.group(0)!)
If, by some chance, you happened to have any null values, this code will not work (as I said, I believe you won't but what do I know? I've never used regexes with dart)
If that's the case, you first need to filter the null values and then use the !:
regExp.allMatches(decrypted)
.map((z) => z.group(0))
.where((v) => v != null) // filter out null values
.map((v) => v!); // let dart know you don't have any null values.
Hopefully that's enough to fix the problem
I'm using a FormTextField in a Flutter app
To update a certain column value, the user types in the FormTextField, otherwise leaves the field empty.
I tried this code, but it was adding a null value to the column, deleting the existing value. I'm not happy with this behavior.
String _getProd5Name() {
if ((_prod5Controller.text).isNotEmpty == true) {
_prod5String = _prod5Controller.text;
}
return _prod5String;
}
Is there a way to do it?
I found similar questions, but they are relevant to other languages and their solutions don't solve my case.
String _getProd5Name() {
// Actually you don't have to make it private
// since this is a local variable inside a function
String _prod5String = variableContainingInitialValue;
if (_prod5Controller.text.isNotEmpty) {
_prod5String = _prod5Controller.text;
}
return _prod5String;
}
Here is my advice, since I love wrapping everything on 1 line. You can change the "" part with your result expectation. It's the same with your logic but it's shorter and instead of returning null I make it returning the empty string "". And also (_prod5Controller.text).isNotEmpty == true you can just shorten it to (_prod5Controller.text).isNotEmpty because .isNotEmpty always returning boolean true/false and if-else consuming boolean
String _getProd5Name() {
return ((_prod5Controller.text).isNotEmpty) ? _prod5String = _prod5Controller.text : "";
}
I'd like to return empty strings on all checkout form field but one (the billing_country one).
I already know how to do it with all fields :
add_filter('woocommerce_checkout_get_value','__return_empty_string', 1, 1);
And how to do it with only one field:
add_filter('woocommerce_checkout_get_value','custom_checkout_get_value_ship_ville', 10, 2);
function custom_checkout_get_value_ship_ville( $value, $imput ){
if($imput == 'shipping_city')
$value = '';
return $value;
}
But for all but one ... I'm a little stucked.
I succeed by duplicating and adapting the previous function, but it's a lot of code for just returning empty strings.
I tried with else, elsif, switch and with logical operators, but no result.
So if someone have some clue ...
Thanks
If you want to return empty strings on every value of $imput except for one specific value you need to reverse the comparison of your second code snippet. So instead of comparing wether the $imput is equal to a value you compare wether the $imput is NOT equal to a value.
You can read up on this comparison here: http://php.net/manual/en/language.operators.comparison.php
You can also just return an empty string directly without assigning it to a variable:
add_filter('woocommerce_checkout_get_value','custom_checkout_get_value_ship_ville', 10, 2);
function custom_checkout_get_value_ship_ville( $value, $imput ){
if($imput != 'billing_country') {
return '';
}
}
I am trying to create two FORMULA fields in Crystal Reports with the same Column in the Database using the following Syntax:
FORMULA1- COLL_DATE
if Collection_Rejection_Desc = 'Cleared'
then Coll_Rej_Dt
else null
FORMULA2- REJ_DATE
if Collection_Rejection_Desc = 'Rejected'
then Coll_Rej_Dt
else null
But it is giving me error saying "a Date and Time Field is expected here"
How can I resolve this?
you can't give one value as date time and other as null in a if condition.. change like this:
FORMULA1- COLL_DATE
if Collection_Rejection_Desc = 'Cleared'
then ToText(Coll_Rej_Dt)
else ""
FORMULA2- REJ_DATE
if Collection_Rejection_Desc = 'Rejected'
then ToText(Coll_Rej_Dt )
else ""
You may want to return Coll_Rej_Dt when the condition is correct, otherwise return null.
you can use Switch by replace if condition. Because in if condition, you need to return same data type in true part and false part.
So, try this...
Switch (Collection_Rejection_Desc = 'Cleared', Coll_Rej_Dt)
Switch (Collection_Rejection_Desc = 'Rejected', Coll_Rej_Dt)
this will return value when the condition is true.
I have a usernameField. On initial state, the field is empty. If I log in successfully, and log back out, it remembers my username for me.
Trying to create a test case for iOS (in swift) that will clear out the field (use the clearText button) if the field has content and then enter a desired string. If it's empty, it needs to skip the clearText button action (since it doesn't exist when the field value is nil) and go straight to entering the username.
It always skips the if statement, even when it's true. Looks for the clearText button, and fails. Works if there's a value in the field, though.
Tried lots of different approaches, but here's my best current working code. Open to any suggestions, as I have no one to really help me learn this stuff. I'm sure I'm just missing something fundamental:
let staffusernameloginfield = app.scrollViews.otherElements.textFields["staffUsernameLoginField"]
staffusernameloginfield.tap()
func checkUsernameFieldContents() {
if staffusernameloginfield == (Content:nil) {
staffusernameloginfield.typeText("owner")
}
else {
elementsQuery.buttons["Clear text"].tap()
staffusernameloginfield.typeText("owner")
}
}
checkUsernameFieldContents()
Have also tried:
if staffusernameloginfield == ("") {
staffusernameloginfield.typeText("owner")
}
else {
elementsQuery.buttons["Clear text"].tap()
staffusernameloginfield.typeText("owner")
}
}
I know that I could hack it by having it always enter a value into the field and then clear it out and enter the desired value, but in this test case, I'm not trying to test for that.
I would compare the value (raw attribute of the element). This type can vary so I always do it as a string:
if staffusernameloginfield.value as! String == "" {
staffusernameloginfield.typeText("owner")
}
else {
elementsQuery.buttons["Clear text"].tap()
staffusernameloginfield.typeText("owner")
}
Now it should enter 'owner' if it sees there is no value in staffusernameloginfield.
to check if the textfield is empty:
app.textFields["signInEmailAddressTextFieldLabel"].value as? String == ""
if the textfield is empty, then that's true
I usually use an assert to check if the value is empty or not, in this example the value is equal to a variable incorrectPassword:
XCTAssertEqual(app.textFields["\(passwordSecureTextFieldLabel)"].value as? String, incorrectPassword)