I have a constants file with text values, for example:
const String loginIntro1 = "Login to account";
const String loginButton = "Login";
And I also have a Map containing similar info, for example:
{"loginIntro1":"Login to account","loginButton":"Login"}
The idea is that the Map (derived from a JSON file) takes precedence, but if the value doesn't exist, the constants value is used instead.
In my text widget, I want to grab the text by a method call, such as:
getText('loginIntro1');
Is this even possible? How can I get the value from the constants file with a String, rather than a direct reference to the variable? Perhaps I'm missing a much simpler way of achieving this!
Related
i am new in dart and just want to know how to take integer input from user in dart with null safety. i found out a way to take number input from dart which is:
String? chossenNumber = stdin. readLineSync();
if(chossenNumber !=null)
{
int number = int.parse(chossenNumber);
}
but i am unable to use number variable outside of the scope. Please tell me a way to solve this issue.
You can define the variable at the top of the class and initialize it here so you will be able to use it everywhere in the class
The solution of it very simple just take input of number as String i.e
String? chossenNumber = stdin. readLineSync();
and when you want to use this variable parse it to the 'int' i.e
if(int.parse(chossenNumber) <100)
{
print("Your Statement");
}
I have a variable that contains a string with interpolated variables. In the code below, that variable is template. When I pass this variable to generateString function, I want to apply string interpolation on it because the values which interpolated variables require are available in generateString function only.
void main() {
String template = '<p>\${name}</p>';
var res = generateString(template);
}
generateString(template) {
var name = 'abc';
print(template);
return template;
}
The problem is when I am printing and returning template inside generateString fn, I am getting <p>${name}</p> instead of <p>abc</p>. Is there a way to explicitly tell the dart to so string interpolation?
I am new to Dart. I don't know if it is even possible to achieve or not. Please suggest how do I do this.
Edit: Based on the inputs from other users, I would like to make a clarification about the scenario presented. The value of template variable is not a string literal. I get that from UI as a user input. I have shown it here as a string literal for code simplicity. Also, please consider that name and template are not in the same scope in my scenario.
The other answers so far are wrong.
String interpolation (looking for $, etc) happens only while compiling from the source code to the value in memory. If that string in turn also has a $, it's no longer special.
It's not possible to trigger interpolation past the original compilation step. You can write a templating system that would look for something like {{name}} in the value, and replace it with the current value of name.
If you have the template and the variable in the same scope, it works as expected.
// evaluate variable inside ${}
var sport = 'basketball';
String template = 'I like <p>${sport}</p>';
print(template);
I didn't fully understand your question maybe this will help
void main() {
print(generateString('abc')); //<p>abc</p>
}
generateString(String template) {
return r"<p>" "$template" r"</p>";
}
Walter White here.
You must define the variable name as global var, so it can "cook" the string for you
I apologize for what seems to be an exceedingly simple question, but after 4 hours of searching and beating my head against the wall, I'm doubting my sanity.
I need a string format expression that trims a supplied string argument much like Substring(0,1). Although I've never seen this in code, it just seems like it should be possible.
Here's a very basic example of what I'm trying to do:
string ClassCode = "B608H2014"; // sample value from the user's class schedule
string fRoom = "{0:0,2}";
string fGrade = "{0:2,2}";
string fYear = "{0:5,4}";
string Classroom = String.Format(fRoom, ClassCode); // intended result - "B6"
string Gradelevel = String.Format(fGrade, ClassCode); // intended result - "08"
string Schoolyear = String.Format(fYear, ClassCode); // intended result - "2014"
This is a very basic example, but I'm trying to use the String.Format() so I can store the format pattern(s) in the database for each respective DTO property since the class code layouts are not consistent. I can just pass in the formats from the database along with the required properties and it extracts what I need.
Does this make sense?
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'm working on a new application and i need to make a messages interface with lookup, using the key to find the value (like ConstantsWithLookup, but capable to receive parameters). I have being investigating Dictionary class functionality but it lacks message customization through parameters.
With ConstantsWithLookup i can make the following:
myConstantsWithLookupInterface.getString("key");
and get something like:
Field must be filled with numbers
But i need to do this:
myMessagesWithLookupInterface.getString("key", "param1", "param2",...);
and get something like:
Field _param1_ must be filled with numbers greater than _param2_
I have no clue how to do this.
Use GWT regular expressions:
//fields in your class
RegEx pattern1 = RegEx.compile("_param1_");
RegEx pattern2 = RegEx.compile("_param2_");
public String getString(String key, String replace1, String replace2){
// your original getString() method
String content = getString(key);
content = pattern1.replace(content,replace1);
content = pattern2.replace(content,replace2);
return content;
}
If your data contains Field _param1_ must be filled with numbers greater than _param2_ then this will replace _param1_ with content of string replace1.