Atributos globais

Os atributos globais podem ser especificados em todos os elementos HTML, mesmo aqueles que não estão especificados no padrão. Isso significa que qualquer elemento não padrão ainda deve permitir esses atributos, mesmo que utilizando esses elementos significa que o documento já não é mais compatível com HTML5. Por exemplo, navegadores compatíveis com HTML5 ocultam conteúdo marcado como <foo hidden>...<foo>, mesmo que <foo> não seja um elemento HTML válido.

Além dos atributos globais HTML básicos, também existem os seguintes atributos globais:

• xml:lang and xml:base — these are inherited from the XHTML specifications and deprecated, but kept for compatibility purposes.
• The multiple aria-* attributes, used for improving accessibility.
• The event handler attributes: onabort, onautocomplete, onautocompleteerror, onblur, oncancel, oncanplay, oncanplaythrough, onchange, onclick, onclose, oncontextmenu, oncuechange, ondblclick, ondrag, ondragend, ondragenter, ondragexit, ondragleave, ondragover, ondragstart, ondrop, ondurationchange, onemptied, onended, onerror, onfocus, oninput, oninvalid, onkeydown, onkeypress, onkeyup, onload, onloadeddata, onloadedmetadata, onloadstart, onmousedown, onmouseenter, onmouseleave, onmousemove, onmouseout, onmouseover, onmouseup, onmousewheel, onpause, onplay, onplaying, onprogress, onratechange, onreset, onresize, onscroll, onseeked, onseeking, onselect, onshow, onsort, onstalled, onsubmit, onsuspend, ontimeupdate, ontoggle, onvolumechange, onwaiting.

accesskey

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.

class

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

contenteditable

Is 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

Is the id of an <menu> to use as the contextual menu for this element.

data-*

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

Is 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 let the user agent decides. It uses a basic algorithm as it parses the characters inside the element until it finds a character with a strong directionality, then apply that directionality to the whole element.

draggable

Is 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.

dropzone

Is an enumerated attribute indicating what types of content can be dropped on an element, using the Drag and Drop API. It can have the following values:

• copy, which indicates that dropping will create a copy of the element that was dragged
• move, which indicates that the element that was dragged will be moved to this new location.
• link, will create a link to the dragged data.

hidden

Is a Boolean attribute indicates 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.

id

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).

itemid

The unique, global identifier of an item.

itemprop

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

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

itemscope

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

Specifies the URL of the vocabulary that will be used to define itemprop's (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

Participates in defining the language of the element, the language that non-editable elements are written in or the language that editable elements should be written in. The tag contains one single entry value in the format defined in the Tags for Identifying Languages (BCP47) IETF document. xml:lang has priority over it.

slot

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

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

• 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

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

Is 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 takes 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 which means should be focusable and reachable via sequential keyboard navigation; its relative order is defined by the value of the attribute: the sequential follow the increasing number of the tabindex. If several elements share the same tabindex, their relative order follows their relative position in the document).

title

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

Is 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 and "yes", which indicates that the element will be translated.
• "no", which indicates that the element will not be translated.

• Interfaces Element e GlobalEventHandlers que permitem-lhe consultar a maioria dos atributos globais.