El

El<S> is an HTML element on a page whose signals are S. Its methods return the element, so a tree is one expression.

Content and attributes

Item	Summary
`child`	Appends a child element, text, or template.
`children`	Appends several children. An `Option` counts as zero or one child.
`text`	Appends static text.
`attr`	Sets a plain attribute.
`href`	Sets the element's `href`: a link to a page the router serves, or a `SafeUrl` for an address it does not.
`src`	Sets the element's `src`, the address of the image, frame, or script it loads, as `El::href` sets `href`.
`id`	Sets the element's `id`.
`class`	Adds a static class.
`css`	Adds the declarations of `style` as atomic classes.
`node_ref`	Attaches `node_ref`, so its statements act on this element.
`foreign`	Leaves this element's attributes and children to a script, and names it `node_ref`.
`render`	Renders the element and its children to an HTML string.

Each binding takes an expression over the signals, and the runtime updates the element with the expression's value whenever a signal changes.

Item	Summary
`bind_text`	Replaces the element's text with `text`, kept up to date as signals change.
`show`	Shows the element only while `when` is true.
`bind_attr`	Keeps attribute `name` equal to `value` as signals change.
`attr_when`	Sets the boolean attribute `name`, such as `disabled`, while `when` is true.
`disabled`	Disables the control while `when` is true, through `disabled`.
`class_when`	Adds `class` while `when` is true.
`css_when`	Adds the declarations of `style` while `when` is true.
`css_match`	Adds the style of the case whose value `value` equals.
`bind_style`	Keeps the CSS property `property` equal to `value` as signals change.
`bind_token`	Keeps `token` equal to `value` on this element and those inside it.
`bind`	Binds a form control to a signal in both directions.
`bind_checked`	Keeps a checkbox's `checked` state equal to `when`, in one direction.
`bind_radio`	Makes this radio button set `signal` to `value` when checked.
`bind_select`	Fills this `<select>` with `options` and binds it to `signal`.

Item	Summary
`on`	Runs `stmt` on `event`. When `on` is called twice for the same event, the second statement runs after the first.
`on_click`	Runs `stmt` on click.
`on_double_click`	Runs `stmt` on double click.
`on_input`	Runs `stmt` on every edit of a text field.
`on_change`	Runs `stmt` on `change`.
`on_submit`	Runs `stmt` when a form is submitted, after `preventDefault`.
`on_blur`	Runs `stmt` when focus leaves the element.
`on_visible`	Runs `stmt` each time the element comes into the viewport.
`on_key`	Runs `stmt` when `shortcut` is pressed while focus is in this element.
`on_debounced`	Runs `stmt` once `event` has stopped firing for `quiet`.
`on_custom`	Runs the statement `handle` builds whenever `event` reaches this element.

Item	Summary
`on_load`	Runs `stmt` once when the element is added to the document.
`on_interval`	Runs `stmt` every `period` while the element is in the document.
`on_timeout`	Runs `stmt` once, `delay` after the element is added to the document, if it is still in it then.
`effect`	Runs `stmt` when the element is added to the document and whenever a signal `stmt` reads changes.
`on_signal_change`	Runs `stmt` whenever `signal`, or any field inside it, changes.
`roving_focus`	Moves focus between the items inside this element on the arrow keys, Home, and End.
`active_descendant`	Tracks the active option of `listbox` in `active` on the up and down arrows.