Struct HtmlForm

pub struct HtmlForm<'a> {
    pub action: &'a str,
    pub method: Method,
    pub errors: HashMap<String, String>,
    pub fields: Vec<Field<'a>>,
}

HtmlForm represents an HTML form. It is used to validate data (both on the server and the client side) and to serialize forms in a consistent manner (either as JSON or using a template language of choice). The builder-style API makes it relatively easy to define forms:

use es_htmlform::HtmlForm;
use es_htmlform::value::ValueMap;
use es_htmlform::types::{Method, InputType, Constraint, Attr};

fn main() {
    // user input
    let values = ValueMap::from_urlencoded(b"foo=bar").unwrap();
    let mut form = HtmlForm::new(".", Method::Post)
        .input(
            InputType::Text, "foo", "Foo", true,
            vec![], vec![]).unwrap()
        .submit(None, "Submit", vec![]).unwrap();
    form.update(&values, true);
    assert_eq!(form.errors.len(), 0);
    assert_eq!(form.get_string("foo").unwrap(), "bar");
}

Fields

action: &'a str

method: Method

errors: HashMap<String, String>

fields: Vec<Field<'a>>

Implementations

impl<'a> HtmlForm<'a>

pub fn new(action: &'a str, method: Method) -> HtmlForm<'a>

Instantiate an HtmlForm.

pub fn update(&mut self, values: &ValueMap, check_required: bool)

Validate the values in a ValueMap and save them on the form

This populates self.errors and the values in self.fields, the latter regardless of whether the values are valid (this to allow presenting a form with errors with the old values pre-filled - note that password fields are emptied on serialization).

Example:

use es_htmlform::HtmlForm;
use es_htmlform::value::ValueMap;
use es_htmlform::types::{Method, InputType, Constraint};

fn main() {
    let mut form = HtmlForm::new(".", Method::Post)
        .input(
            InputType::Text, "foo", "Foo", true,
            vec![Constraint::MinLength(5)], vec![]).unwrap();
    form.update(
        &ValueMap::from_urlencoded(b"foo=bar").unwrap(), true);
    assert_eq!(
        form.errors.get("foo").unwrap(),
        "Must be at least 5 characters long.");
    assert_eq!(form.get::<String>("foo").unwrap(), vec!["bar"]);
}

pub fn field(self, name: &str) -> Result<Field<'a>, FormError>

Return a Field by name, or an error if there is not field by that name.

pub fn get<T>(&self, name: &str) -> Result<Vec<T>, FormError>

where T: FromStr,

Return a list of values of a field, parsed to T. Returns an error when the field is not found, when the values can not be converted (parsed) or when the field has no value.

pub fn getone<T>(&self, name: &str) -> Result<T, FormError>

where T: FromStr,

Return a single value for a field, parsed to T. Returns an error when the field is not found, when more than one value is found, when the value can not be converted (parsed) or when the field has no value.

pub fn get_strings(&self, name: &str) -> Result<Vec<String>, FormError>

Return a list of values of a field, as Strings. Returns an error when the field is not found or when the field has no value.

pub fn get_string(&self, name: &str) -> Result<String, FormError>

Return a single value for a field as String. Returns an error when the field is not found, when more than one value is found, or when the field has no value.

pub fn input( self, input_type: InputType, name: &'a str, label: &'a str, required: bool, constraints: Vec<Constraint<'a>>, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create an input element, use this for non-collection fields (so not for InputType::Radio or InputType::Checkbox, for those see choice_input()). Returns self, so calls can be chained.

pub fn checkbox( self, name: &'a str, label: &'a str, required: bool, choices: &'a [(&'a str, &'a str)], attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a set of checkboxes. Returns self, so calls can be chained.

pub fn radio( self, name: &'a str, label: &'a str, required: bool, choices: &'a [(&'a str, &'a str)], attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a set of radio buttons. Returns self, so calls can be chained.

pub fn datalist_input( self, input_type: InputType, name: &'a str, label: &'a str, required: bool, datalist: &'a [(&'a str, &'a str)], attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a text(-style) input with datalist for auto-fill suggestions. Returns self, so calls can be chained.

pub fn hidden( self, name: &'a str, value: Option<&str>, required: bool, constraints: Vec<Constraint<'a>>, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

pub fn textarea( self, name: &'a str, label: &'a str, required: bool, constraints: Vec<Constraint<'a>>, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a textarea without validation. Returns self, so calls can be chained.

pub fn select( self, name: &'a str, label: &'a str, multi: bool, required: bool, choices: &'a [(&'a str, &'a str)], attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a select dropdown. Returns self, so calls can be chained.

pub fn submit( self, name: Option<&'a str>, label: &'a str, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a submit button. Returns self, so calls can be chained.

pub fn reset( self, label: &'a str, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a reset button. Returns self, so calls can be chained.

pub fn button( self, button_type: ButtonType, name: &'a str, label: &'a str, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Shortcut to create a button element. Returns self, so calls can be chained.

pub fn element( self, element: Element, name: &'a str, label: &'a str, required: bool, values: Option<Vec<&str>>, choices: &'a [(&'a str, &'a str)], constraints: Vec<Constraint<'a>>, attributes: Vec<Attr<'a>>, ) -> Result<Self, FormError>

Create an field of any type. This is similar to Field::new(), but some checks and conversions are performed. Returns self, so calls can be chained.

Trait Implementations

impl<'a> Debug for HtmlForm<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Serialize for HtmlForm<'a>

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.