1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
from textual import on
from textual.app import App, ComposeResult
from textual.validation import Function, Number, ValidationResult, Validator
from textual.widgets import Input, Label, Pretty
class InputApp(App):
# (6)!
CSS = """
Input.-valid {
border: tall $success 60%;
}
Input.-valid:focus {
border: tall $success;
}
Input {
margin: 1 1;
}
Label {
margin: 1 2;
}
Pretty {
margin: 1 2;
}
"""
def compose(self) -> ComposeResult:
yield Label("Enter an even number between 1 and 100 that is also a palindrome.")
yield Input(
placeholder="Enter a number...",
validators=[
Number(minimum=1, maximum=100), # (1)!
Function(is_even, "Value is not even."), # (2)!
Palindrome(), # (3)!
],
)
yield Pretty([])
@on(Input.Changed)
def show_invalid_reasons(self, event: Input.Changed) -> None:
# Updating the UI to show the reasons why validation failed
if not event.validation_result.is_valid: # (4)!
self.query_one(Pretty).update(event.validation_result.failure_descriptions)
else:
self.query_one(Pretty).update([])
def is_even(value: str) -> bool:
try:
return int(value) % 2 == 0
except ValueError:
return False
# A custom validator
class Palindrome(Validator): # (5)!
def validate(self, value: str) -> ValidationResult:
"""Check a string is equal to its reverse."""
if self.is_palindrome(value):
return self.success()
else:
return self.failure("That's not a palindrome :/")
@staticmethod
def is_palindrome(value: str) -> bool:
return value == value[::-1]
app = InputApp()
if __name__ == "__main__":
app.run()
|
