Struct Meta

pub struct Meta<'life> {

    pub accesskey: Option<AttributeValue<'life>>,
    pub autocapitalize: Option<AttributeValue<'life>>,
    pub autofocus: Option<AttributeValue<'life>>,
    pub charset: Option<AttributeValue<'life>>,
    pub class: Option<AttributeValue<'life>>,
    pub content: Option<AttributeValue<'life>>,
    pub contenteditable: Option<AttributeValue<'life>>,
    pub contextmenu: Option<AttributeValue<'life>>,
    pub data: BTreeMap<&'life str, AttributeValue<'life>>,
    pub dir: Option<AttributeValue<'life>>,
    pub draggable: Option<AttributeValue<'life>>,
    pub enterkeyhint: Option<AttributeValue<'life>>,
    pub exportparts: Option<AttributeValue<'life>>,
    pub extra: BTreeMap<&'life str, AttributeValue<'life>>,
    pub hidden: Option<AttributeValue<'life>>,
    pub http_equiv: Option<AttributeValue<'life>>,
    pub id: Option<AttributeValue<'life>>,
    pub inert: Option<AttributeValue<'life>>,
    pub inputmode: Option<AttributeValue<'life>>,
    pub is: Option<AttributeValue<'life>>,
    pub itemid: Option<AttributeValue<'life>>,
    pub itemprop: Option<AttributeValue<'life>>,
    pub itemref: Option<AttributeValue<'life>>,
    pub itemscope: Option<AttributeValue<'life>>,
    pub itemtype: Option<AttributeValue<'life>>,
    pub lang: Option<AttributeValue<'life>>,
    pub name: Option<AttributeValue<'life>>,
    pub nonce: Option<AttributeValue<'life>>,
    pub part: Option<AttributeValue<'life>>,
    pub popover: Option<AttributeValue<'life>>,
    pub role: Option<AttributeValue<'life>>,
    pub slot: Option<AttributeValue<'life>>,
    pub spellcheck: Option<AttributeValue<'life>>,
    pub style: Option<AttributeValue<'life>>,
    pub tabindex: Option<AttributeValue<'life>>,
    pub title: Option<AttributeValue<'life>>,
    pub translate: Option<AttributeValue<'life>>,
    pub virtualkeyboardpolicy: Option<AttributeValue<'life>>,
}

The <meta> HTML element represents metadata that cannot be represented by other HTML meta-related elements, like <base>, <link>, <script>, <style> or <title>.

The type of metadata provided by the <meta> element can be one of the following:

More information: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta

Fields

accesskey: Option<AttributeValue<'life>>

Provides a hint for generating a keyboard shortcut for the current element. This attribute consists of a space-separated list of characters. The browser should use the first one that exists on the computer keyboard layout.

autocapitalize: Option<AttributeValue<'life>>

Controls whether and how text input is automatically capitalized as it is entered/edited by the user. It can have the following values:

• off or none, no autocapitalization is applied (all letters default to lowercase)
• on or sentences, the first letter of each sentence defaults to a capital letter; all other letters default to lowercase
• words, the first letter of each word defaults to a capital letter; all other letters default to lowercase
• characters, all letters should default to uppercase

autofocus: Option<AttributeValue<'life>>

Indicates that an element is to be focused on page load, or as soon as the <dialog> it is part of is displayed. This attribute is a boolean, initially false.

charset: Option<AttributeValue<'life>>

This attribute declares the document's character encoding. If the attribute is present, its value must be an ASCII case-insensitive match for the string "utf-8", because UTF-8 is the only valid encoding for HTML5 documents. <meta> elements which declare a character encoding must be located entirely within the first 1024 bytes of the document.

class: Option<AttributeValue<'life>>

A space-separated list of the classes of the element. Classes allow CSS and JavaScript to select and access specific elements via the class selectors or functions like the method Document.getElementsByClassName().

content: Option<AttributeValue<'life>>

This attribute contains the value for the http-equiv or name attribute, depending on which is used.

contenteditable: Option<AttributeValue<'life>>

An enumerated attribute indicating if the element should be editable by the user. If so, the browser modifies its widget to allow editing. The attribute must take one of the following values:

• true or the empty string, which indicates that the element must be editable;
• false, which indicates that the element must not be editable.

contextmenu: Option<AttributeValue<'life>>

The id of a <menu> to use as the contextual menu for this element.

data: BTreeMap<&'life str, AttributeValue<'life>>

Forms a class of attributes, called custom data attributes, that allow proprietary information to be exchanged between the HTML and its DOM representation that may be used by scripts. All such custom data are available via the HTMLElement interface of the element the attribute is set on. The HTMLElement.dataset property gives access to them.

dir: Option<AttributeValue<'life>>

An enumerated attribute indicating the directionality of the element's text. It can have the following values:

• ltr, which means left to right and is to be used for languages that are written from the left to the right (like English);
• rtl, which means right to left and is to be used for languages that are written from the right to the left (like Arabic);
• auto, which lets the user agent decide. It uses a basic algorithm as it parses the characters inside the element until it finds a character with a strong directionality, then it applies that directionality to the whole element.

draggable: Option<AttributeValue<'life>>

An enumerated attribute indicating whether the element can be dragged, using the Drag and Drop API. It can have the following values:

• true, which indicates that the element may be dragged
• false, which indicates that the element may not be dragged.

enterkeyhint: Option<AttributeValue<'life>>

Hints what action label (or icon) to present for the enter key on virtual keyboards.

exportparts: Option<AttributeValue<'life>>

Used to transitively export shadow parts from a nested shadow tree into a containing light tree.

extra: BTreeMap<&'life str, AttributeValue<'life>>

/// Extra attributes of the element. This is a map of attribute names to their values, and the attribute names are in lowercase.

hidden: Option<AttributeValue<'life>>

An enumerated attribute indicating that the element is not yet, or is no longer, relevant. For example, it can be used to hide elements of the page that can't be used until the login process has been completed. The browser won't render such elements. This attribute must not be used to hide content that could legitimately be shown.

http_equiv: Option<AttributeValue<'life>>

Defines a pragma directive. The attribute is named http-equiv(alent) because all the allowed values are names of particular HTTP headers:

• content-security-policy Allows page authors to define a content policy for the current page. Content policies mostly specify allowed server origins and script endpoints which help guard against cross-site scripting attacks.
• content-type Declares the MIME type and the document's character encoding. The content attribute must have the value "text/html; charset=utf-8" if specified. This is equivalent to a <meta> element with the charset attribute specified and carries the same restriction on placement within the document. Note: Can only be used in documents served with a text/html — not in documents served with an XML MIME type.
• default-style Sets the name of the default CSS style sheet set.
• x-ua-compatible If specified, the content attribute must have the value "IE=edge". User agents are required to ignore this pragma.
• refresh This instruction specifies:
  • The number of seconds until the page should be reloaded - only if the content attribute contains a non-negative integer.
  • The number of seconds until the page should redirect to another - only if the content attribute contains a non-negative integer followed by the string ';url=', and a valid URL.

  Warning:

  Pages set with a refresh value run the risk of having the time interval being too short. People navigating with the aid of assistive technology such as a screen reader may be unable to read through and understand the page's content before being automatically redirected. The abrupt, unannounced updating of the page content may also be disorienting for people experiencing low vision conditions.

  • MDN Understanding WCAG, Guideline 2.1 explanations
  • MDN Understanding WCAG, Guideline 3.1 explanations
  • Understanding Success Criterion 2.2.1 | W3C Understanding WCAG 2.0
  • Understanding Success Criterion 2.2.4 | W3C Understanding WCAG 2.0
  • Understanding Success Criterion 3.2.5 | W3C Understanding WCAG 2.0

id: Option<AttributeValue<'life>>

Defines a unique identifier (ID) which must be unique in the whole document. Its purpose is to identify the element when linking (using a fragment identifier), scripting, or styling (with CSS).

inert: Option<AttributeValue<'life>>

A boolean value that makes the browser disregard user input events for the element. Useful when click events are present.

inputmode: Option<AttributeValue<'life>>

Provides a hint to browsers about the type of virtual keyboard configuration to use when editing this element or its contents. Used primarily on <input> elements, but is usable on any element while in contenteditable mode.

is: Option<AttributeValue<'life>>

Allows you to specify that a standard HTML element should behave like a registered custom built-in element (see Using custom elements for more details).

itemid: Option<AttributeValue<'life>>

The unique, global identifier of an item.

itemprop: Option<AttributeValue<'life>>

Used to add properties to an item. Every HTML element may have an itemprop attribute specified, where an itemprop consists of a name and value pair.

itemref: Option<AttributeValue<'life>>

Properties that are not descendants of an element with the itemscope attribute can be associated with the item using an itemref. It provides a list of element ids (not itemids) with additional properties elsewhere in the document.

itemscope: Option<AttributeValue<'life>>

itemscope (usually) works along with itemtype to specify that the HTML contained in a block is about a particular item. itemscope creates the Item and defines the scope of the itemtype associated with it. itemtype is a valid URL of a vocabulary (such as schema.org) that describes the item and its properties context.

itemtype: Option<AttributeValue<'life>>

Specifies the URL of the vocabulary that will be used to define itemprops (item properties) in the data structure. itemscope is used to set the scope of where in the data structure the vocabulary set by itemtype will be active.

lang: Option<AttributeValue<'life>>

Helps define the language of an element: the language that non-editable elements are in, or the language that editable elements should be written in by the user. The attribute contains one "language tag" (made of hyphen-separated "language subtags") in the format defined in RFC 5646: Tags for Identifying Languages (also known as BCP 47). xml:lang has priority over it.

name: Option<AttributeValue<'life>>

The name and content attributes can be used together to provide document metadata in terms of name-value pairs, with the name attribute giving the metadata name, and the content attribute giving the value.

See standard metadata names for details about the set of standard metadata names defined in the HTML specification.

nonce: Option<AttributeValue<'life>>

A cryptographic nonce ("number used once") which can be used by Content Security Policy to determine whether or not a given fetch will be allowed to proceed.

part: Option<AttributeValue<'life>>

A space-separated list of the part names of the element. Part names allows CSS to select and style specific elements in a shadow tree via the ::part pseudo-element.

popover: Option<AttributeValue<'life>>

Specifies that the element should be treated like a popover. An element with the popover attribute is hidden from the page unless it is opened by interacting with an invoking element that has popovertarget, or via showPopover().

role: Option<AttributeValue<'life>>

Roles define the semantic meaning of content, allowing screen readers and other tools to present and support interaction with an object in a way that is consistent with user expectations of that type of object. roles are added to HTML elements using role="role_type", where role_type is the name of a role in the ARIA specification.

slot: Option<AttributeValue<'life>>

Assigns a slot in a shadow DOM shadow tree to an element: An element with a slot attribute is assigned to the slot created by the <slot> element whose name attribute's value matches that slot attribute's value.

spellcheck: Option<AttributeValue<'life>>

An enumerated attribute defines whether the element may be checked for spelling errors. It may have the following values:

• empty string or true, which indicates that the element should be, if possible, checked for spelling errors;
• false, which indicates that the element should not be checked for spelling errors.

style: Option<AttributeValue<'life>>

Contains CSS styling declarations to be applied to the element. Note that it is recommended for styles to be defined in a separate file or files. This attribute and the <style> element have mainly the purpose of allowing for quick styling, for example for testing purposes.

tabindex: Option<AttributeValue<'life>>

An integer attribute indicating if the element can take input focus (is focusable), if it should participate to sequential keyboard navigation, and if so, at what position. It can take several values:

• a negative value means that the element should be focusable, but should not be reachable via sequential keyboard navigation;
• 0 means that the element should be focusable and reachable via sequential keyboard navigation, but its relative order is defined by the platform convention;
• a positive value means that the element should be focusable and reachable via sequential keyboard navigation; the order in which the elements are focused is the increasing value of the tabindex. If several elements share the same tabindex, their relative order follows their relative positions in the document.

title: Option<AttributeValue<'life>>

Contains a text representing advisory information related to the element it belongs to. Such information can typically, but not necessarily, be presented to the user as a tooltip.

translate: Option<AttributeValue<'life>>

An enumerated attribute that is used to specify whether an element's attribute values and the values of its Text node children are to be translated when the page is localized, or whether to leave them unchanged. It can have the following values:

• empty string or yes, which indicates that the element will be translated.
• no, which indicates that the element will not be translated.

virtualkeyboardpolicy: Option<AttributeValue<'life>>

An enumerated attribute used to control the on-screen virtual keyboard behavior on devices such as tablets, mobile phones, or other devices where a hardware keyboard may not be available for elements that also uses the contenteditable attribute.

• auto or an empty string, which automatically shows the virtual keyboard when the element is focused or tapped.
• manual, which decouples focus and tap on the element from the virtual keyboard's state.

Implementations

impl<'life> Meta<'life>

pub fn tag() -> &'static str

Get the tag name of the element. This is the same as the name of the struct, in kebab-case.

pub fn set_attr( &mut self, name: &'life str, value: impl Into<AttributeValue<'life>>, )

Sets an attribute of the element. This sets the attribute of the struct. If the attribute is not a known attribute, it is added to the extra map. If the alloc feature is disabled, this function will silently fail.

Note

This only works when the attribute is lowercase.

Trait Implementations

impl<'life> Clone for Meta<'life>

fn clone(&self) -> Meta<'life>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'life> Debug for Meta<'life>

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

Formats the value using the given formatter.

impl<'life> Default for Meta<'life>

fn default() -> Meta<'life>

Returns the “default value” for a type.

impl<'life> Ord for Meta<'life>

fn cmp(&self, other: &Meta<'life>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<'life> PartialEq for Meta<'life>

fn eq(&self, other: &Meta<'life>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'life> PartialOrd for Meta<'life>

fn partial_cmp(&self, other: &Meta<'life>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'life> Eq for Meta<'life>

impl<'life> StructuralPartialEq for Meta<'life>