You need to keep those values in a global file which gets included in the app. Make sure to name it correctly to avoid conflict.
Something like-
MyApp = {
config:{
property1:'value1',
property2:'value2'
}
}
Then you can access these values like-
myProperty1 = MyApp.config.property1;
Hope, it helps :)
Reference:
javascript - How to read values from properties file in ExtJs - Stack Overflow[
^]