feat: AsFormField for Date, Time, DateTime (#342)

* AsFormField for Date, Time, DateTime

* add some tests and basic docs

* more fixes

* remove wrapped types

* add more docs and attributes

* add form support for DateTime<FixedOffset>

* fix error message

* minor fixes

* turn on alloc feature for chrono

* some more minor improvs

* more improvs

* move steps into attrs

* refactor

* rebase

* use chrono_tz for Timezone field

* make clippy happy

* remove unnecessary test name demarcation

* add basic form example

* fix CI

* more unnecessary code removal

* Update examples/forms/templates/index.html

Co-authored-by: Mateusz Maćkowski <mateusz@mackowski.org>

* address comments

* rebase

* fix tests

* remove lingering code as a result of the rebase

* chore(pre-commit.ci): auto fixes from pre-commit hooks

* add more variants

* minor formatting

---------

Co-authored-by: Mateusz Maćkowski <mateusz@mackowski.org>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

Cargo.lock

@@ -13,6 +13,7 @@ members = [
     "examples/json",
     "examples/sessions",
     "examples/todo-list",
+    "examples/forms"
 ]
 resolver = "2"
 
@@ -63,6 +64,7 @@ backtrace = "0.3"
 bytes = "1.10"
 cargo_toml = "0.22"
 chrono = { version = "0.4.41", default-features = false }
+chrono-tz = { version = "0.10.3", default-features = false }
 clap = { version = "4", features = ["deprecated"] }
 clap-verbosity-flag = { version = "3", default-features = false }
 clap_complete = "4"

Cargo.toml

@@ -22,7 +22,8 @@ async-trait.workspace = true
 axum = { workspace = true, features = ["http1", "tokio"] }
 backtrace.workspace = true
 bytes.workspace = true
-chrono = { workspace = true, features = ["serde"] }
+chrono = { workspace = true, features = ["alloc", "serde"] }
+chrono-tz.workspace = true
 clap.workspace = true
 cot_macros.workspace = true
 deadpool-redis = { workspace = true, features = ["tokio-comp", "rt_tokio_1"], optional = true }

cot/Cargo.toml

@@ -29,6 +29,8 @@ use std::fmt::Display;
 
 use async_trait::async_trait;
 use bytes::Bytes;
+use chrono::NaiveDateTime;
+use chrono_tz::Tz;
 use cot::error::ErrorRepr;
 /// Derive the [`Form`] trait for a struct and create a [`FormContext`] for it.
 ///
@@ -152,7 +154,20 @@ pub enum FormFieldValidationError {
         /// The maximum permitted value.
         max_value: String,
     },
-
+    /// The field value is an ambiguous datetime.
+    #[error("This is an ambiguous datetime: {datetime}.")]
+    AmbiguousDateTime {
+        /// The ambiguous datetime value.
+        datetime: NaiveDateTime,
+    },
+    /// The field value is a non-existent local datetime.
+    #[error("Local datetime {datetime} does not exist for the given timezone {timezone}.")]
+    NonExistentLocalDateTime {
+        /// The non-existent local datetime value.
+        datetime: NaiveDateTime,
+        /// The timezone in which the datetime was specified.
+        timezone: Tz,
+    },
     /// The field value is required to be true.
     #[error("This field must be checked.")]
     BooleanRequiredToBeTrue,
@@ -207,6 +222,19 @@ impl FormFieldValidationError {
         }
     }
 
+    /// Creates a new `FormFieldValidationError` for an ambiguous datetime.
+    #[must_use]
+    pub fn ambiguous_datetime(datetime: NaiveDateTime) -> Self {
+        FormFieldValidationError::AmbiguousDateTime { datetime }
+    }
+
+    /// Creates a new `FormFieldValidationError` for a non-existent local
+    /// datetime.
+    #[must_use]
+    pub fn non_existent_local_datetime(datetime: NaiveDateTime, timezone: Tz) -> Self {
+        FormFieldValidationError::NonExistentLocalDateTime { datetime, timezone }
+    }
+
     /// Creates a new `FormFieldValidationError` from a `String`.
     #[must_use]
     pub const fn from_string(message: String) -> Self {