o

Instance properties

o.input

An object with the authored-source lookups described in Instance methods. It exists only while Agent Folder Share is active, which needs Chrome or Edge on desktop and a top-level playground. Without a share, o.input is undefined, and calling one of its methods throws a TypeError.

o.pins

A PinList: a live array of pin handles with methods to add, update, capture and delete the pins of the output. It exists in browsers with the share stack, in a top-level playground, and its methods need an active Agent Folder Share.

Instance methods

Each o.input method takes one CSS selector string and returns a Promise. Anything else rejects with TypeError('o.input.<method>() expects a CSS selector string.'). Arrays line up with the matches, in order. A null means that the element has no authored source: it was created at runtime.

o.input.pos()

Resolves to an array with one item per matching element: { start, end }, or null. The offsets are zero-based UTF-16 offsets into the editor source, and end is exclusive.

o.input.sel()

Resolves to an array with one item per matching element: [sl, sc, el, ec, 0], or null. Lines and columns are 1-based. The array is ready to assign to sel, which ignores the null items.

o.input.inner()

Resolves to the authored inner HTML of the first matching element, as a string, or to null. For a void or self-closing element it is ''.

o.input.outer()

Resolves to the authored outer HTML of the first matching element, as a string, or to null.

o.input.innerAll()

Resolves to an array with the authored inner HTML of every matching element: strings and nulls.

o.input.outerAll()

Resolves to an array with the authored outer HTML of every matching element: strings and nulls.

o.input.innerAll.concat()

Resolves to the non-null inner strings of all matches, joined with one \n, like repeated textual o:= bodies. Empty strings are kept. With nothing left it resolves to ''.

o.input.outerAll.concat()

The same for the outer strings.

o.getDimensions()

Returns { aspectRatio: [w, h], x, y, width, height, top, right, bottom, left }, synchronously: the size and position of the output frame as it is displayed in the playground, in the playground's CSS pixels and including the zoom oz. It is not the size of the output's own viewport. getDimensions() describes the method, which every element of the playground window has.

Usage notes

• The strings are the source, not the DOM. They are the exact authored text sliced from the source, with its formatting, entities and attribute quoting, and not a serialization of the live element.
• How a selector is matched. It is tested with Element.matches() on each element, walking depth first from the document element. A host's open shadow tree is visited before its light children, so a descendant combinator does not cross a shadow boundary. inner() and outer() use the first element in that order, even when it has no authored source.
• The output must be in sync. The lookup works on the source map of the output, so the output must have synced the current editor text. See Live sync and reloads and Locating source.
• Before each call the playground waits for the output to finish initializing, and retries one failed initialization. After 15 seconds without an answer the call rejects with a string, not an Error.

Errors

Further InvalidStateError messages that start with IOSync mean that the source records of the output and the editor disagree. Call again after the next sync.

Examples

A page to look up

Open this page in the playground and start Agent Folder Share. The lookups below find its authored source.

<main>
  <h1>Gallery</h1>
  <section class=card>One</section>
  <section class=card>Two</section>
</main>

Looking up authored source

Each line is one command. Write it to io.eval.js and read io.eval.json before the next one.

await o.input.outer('main > h1')        // '<h1>Gallery</h1>'
await o.input.innerAll('.card')          // ['One', 'Two']
await o.input.pos('.card')               // [{ start, end }, { start, end }]
sel = await o.input.sel('.card')         // selects both cards in the editor

If nothing is mapped, because there is no match or the matches were created at runtime, sel receives [] or only nulls, and the cursor moves to line 1, column 1.

Measuring the output

o.getDimensions()   // { aspectRatio: [3, 2], x, y, width: 600, height: 400, … }

Specifications

Not part of any specification. o.input, o.pins and o.getDimensions() are RTCode.io playground features. o is an <iframe> element, and getDimensions() builds on getBoundingClientRect().

Availability

See also

• Playground API
• PinList
• sync
• Selection and layout globals
• Output settings globals
• Locating source
• The IOSync model
• Pins
• Agent Folder Share