FEP-b2b8: Long-form Text

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Summary

Multi-paragraph text is an important content type on the Social Web. This FEP defines best practices for representing and using properties of a long-form text object in Activity Streams 2.0.

Motivation

Blog posts, magazine articles, and forum posts are often made up of multiple paragraphs of text, sometimes with embedded images, video, audio or other media. This important content type is documented in the Activity Vocabulary, but this FEP provides additional guidance for publishers and consumers and collects the relevant properties in one place.

Well-defined behaviour for supporting long-form text provides multiple benefits. Not only does it allow publishers to integrate content in a dependable way across different platforms, but it also gives users of Activity Streams 2.0 consumer applications more control over their reading experience -- including filtering or sorting long-form text objects in their stream.

This FEP does not provide guidance for book-length or longer text.

This document provides information for multiple protocols that use Activity Streams 2.0 as a representation format. Where ActivityPub use is different than AS2, it is noted.

Because long-form text is often syndicated using RSS 2.0, the properties in this FEP are compared to the properties in that format where appropriate.

Type

The Article type is used to represent multi-paragraph text. The Activity Streams 2.0 primer provides guidance on when to use the Article type and when to use the Note type.

Some consumers do not display Article objects with their full content. Some publishers work around this by using a Note-type object with much more content than expected for a note.

Publishers should avoid this workaround, and instead give consumers the full information they need to display the content correctly in their own interfaces. The preview property can be used to provide a simpler version of the content for consumers that don't support Article directly.

Forcing long-form text into a Note object can cause problems for consumers that expect Note objects to be short and well-formatted for stream display. Maintaining a clear distinction between Note and Article objects is important for interoperability.

Consumers that only display short text should show the name, summary and a link to the url property so that users can view the full content in a web browser. As a fallback, they can use the preview property if it is present.

Properties

`id`

A unique identifier for the text. For ActivityPub, this should be an HTTPS URL that resolves to the object. It should be a single string, unique for all objects.

This property provides the same functionality as the guid property in RSS 2.0.

`name`

The title of the text should be in the name property. The property should be short enough to be displayed in a line or two on a browser interface; 75-150 characters is a good rule of thumb. Longer descriptions should be in the summary property.

The name property should be plain text, not HTML or other markup. In particular, no HTML entities like & or < should be used.

This property provides the same functionality as the title property in RSS 2.0.

`url`

The location of the full text should be in the url property. This can be a single string, in which case it is the URL of the HTML representation of the text. It can also be a Link object, which can include additional metadata about the link. If it is a Link object, the mediaType should be 'text/html' and href property should be the URL of the HTML representation of the text.

The url property can also be an array of strings or Link objects or both. Multiple Link objects can be used to represent different media types or provide different URL protocols. At least one of the Link objects should have a mediaType of 'text/html' and a href property with the protocol 'https'.

This property provides the same functionality as the link property in RSS 2.0.

`summary`

This property provides a brief description, teaser, abstract or "lede" for the text. It should be a maximum of about 500 characters; a few sentences; or a short paragraph.

This property can include HTML markup. It should not include embedded media like images, video or audio.

This property provides the same functionality as the description property in RSS 2.0.

`attributedTo`

This property provides the authors of the text, either as a string, an object, or an array.

As a string, it is a single id for the author. For ActivityPub, the id should be a URL that resolves to an ActivityPub actor.

As an object, it can be an AS2 object with a type like Person, Application or Organization. It should have an id and a name property and can also include an icon property for the author's avatar. A summary property can be used to provide a brief description of the author, including HTML. An url property can be used to provide a link to the author's profile page.

If the author does not have an AS2 representation, the attributedTo property can be an object with a type of Link and an href property with the URL of the author's profile page. The name property can be used to provide the author's name.

As an array, the attributedTo property can include multiple authors, either as strings or objects.

The attributedTo property provides the same functionality as the author property of an item in RSS 2.0, with additional features.

`published`

The publication date of the text should be in the published property. This should be a dateTime string in the format YYYY-MM-DDTHH:MM:SSZ.

This property provides the same functionality as the pubDate property in RSS 2.0.

`updated`

If the object has been updated, the date of the last update should be in the updated property. This should be a dateTime string in the format YYYY-MM-DDTHH:MM:SSZ. If the property is not present, consumers can assume that the object has not been modified since the published date.

`image`

The image property provides a notable or representative image for the text. It can be included by reference as an id or with an Image type object.

There can be multiple values for the image property, either as an array of id strings or Image objects. Publishers should provide these in order of importance, with the most important image first. Consumers can use as many or as few as needed.

`content`

The full text of the article or blog post should be in the content property. This should be HTML. Using mediaType to set a different media type presumes that consumers will be able to display that type.

The HTML elements in the content property should include a sanitized subset of the full HTML element set. It should not include any CSS or JavaScript. This subset should include:

<p>
<span> (class)
<h2>, <h3>, <h4>, <h5>, <h6>
<br>
<a> (href, rel, class)
<del>
<pre>
<code>
<em>
<strong>
<b>
<i>
<u>
<ul>
<ol> (start, reversed)
<li> (value)
<blockquote>
<img> (src, alt, title, width, height, class)
<video> (src, controls, loop, poster, width, height, class)
<audio> (src, controls, loop, class)
<source> (src, type)
<ruby>
<rt>
<rp>

The HTML should only include the content of the text. Additional navigation to other pages on the originating site, like category links or home page links, should not be included. Other affordances like "favourite", "like", "bookmark" or other buttons should not be included.

Any embedded media like images, video or audio in the content property should also be listed in the attachment property so that consumers can pre-fetch the media.

`source`

If the text was originally created in a different format, the original source should be in the source property to allow editing the content. It should include the mediaType of the source format and the content property with the original content.

`replies`

Comments on the text should be linked in the replies property. This should be a URL that resolves to a collection of objects for the replies.

Comments are usually Note objects, but can be other types of objects like Article or Question.

This property provides the same functionality as the comments property in RSS 2.0.

`attachment`

The attachment property provides additional media that is part of the text. This can include images, video, audio, or other media. Consumers can use this property to pre-fetch media for display without needing to load and parse the full content property.

If the text is a commentary on or review of a particular link on the Web, the attachment property can include a Link object with a href property that is the URL of the linked resource.

`tag`

The tag property provides additional metadata about the text. There are two important types of tags:

Hashtag objects, which represent a topic or category that the text is about. These should have a name property with the tag text.
Mention objects, which represent a mention of an actor, such as an ActivityPub actor. These should have an href property with the URL of the actor's profile page.

`context`

If the text is part of a larger collection, the context property can provide a link to the collection. An example might be an article in a series, a newspaper column, a blog category (although tag may be better here) or a section of a magazine.

There can be multiple context properties, either as an array of strings or objects or both.

`generator`

The generator property provides information about the software that generated the text. This is usually an Application or Service object with an id and a name property.

`preview`

In AS2, the preview property provides an abbreviated version of the content of the object. Especially for microblogging applications, the preview property is a useful fallback for supporting unrecognized object types like Article.

For an article, the preview can be a Note that gives a well-formatted preview of the article content in its content property. For example, the name, summary, and a link to the url would be an appropriate representation.

The content property of the preview should include a minimal set of HTML elements, as described in ActivityPub Primer HTML.

Metadata on the Article that applies equally to the preview, such as attributedTo, published, updated, and tag should be repeated in the preview property.

The image property of the Article may be included in the preview property as attachment items.

The preview property may have an id property.

`to`, `cc`, `bcc`, `bto`, `audience`

As with other AS2 object types, the to, cc, bcc, bto, and audience properties identify the addressees of the text. For ActivityPub, they also determine the delivery targets of the text.

The addressing properties provide an access control mechanism for AS2. Publishers and consumers should not disclose the properties of any AS2 object type, including the Article type, with anyone except the addressees, listed in these addressing properties, or the creator(s), listed in the attributedTo property.

例

This section includes examples of long-form text objects. Note that for brevity, the content is not actually multi-paragraph text.

Long-form text with included content

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text.jsonld",
  "name": "Long-form text with included content",
  "url": "https://example.com/2024/11/07/long-form-text.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is a long-form text object with included content. It has a title, a summary, and a full text.</p>",
  "content": "<p>This is a long-form text object with included content. It has a title, a summary, and a full text.</p>",
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with external content

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text-no-content.jsonld",
  "name": "Long-form text with included content",
  "url": "https://example.com/2024/11/07/long-form-text-no-content.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is a long-form text object with external content. It has a title, a summary, and a link to the full text.</p>"
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with full author information

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text-author.jsonld",
  "name": "Long-form text with full author information",
  "url": "https://example.com/2024/11/07/long-form-text-author.html",
  "attributedTo": {
    "type": "Person",
    "id": "https://example.com/evan",
    "name": "Evan Prodromou",
    "summary": "<p>Founder of Social Web Foundation</p>",
    "url": "https://example.com/evan",
    "icon": {
      "type": "Image",
      "mediaType": "image/png",
      "url": "https://example.com/evan.png"
    }
  },
  "summary": "<p>This is a long-form text object with full author information. It has a title, a summary, and an URL to the full text.</p>"
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with embedded images

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text-images.jsonld",
  "name": "Long-form text with embedded images",
  "url": "https://example.com/2024/11/07/long-form-text-images.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is a long-form text object with embedded images.</p>",
  "content": "<p>This is a long-form text object with embedded images.</p><img src=\"https://example.com/image1.jpg\" alt=\"Image 1\"><img src=\"https://example.com/image2.jpg\" alt=\"Image 2\">",
  "attachment": [
    {
      "type": "Image",
      "id": "https://example.com/image1.jpg",
      "mediaType": "image/jpeg"
    },
    {
      "type": "Image",
      "id": "https://example.com/image2.jpg",
      "mediaType": "image/jpeg"
    }
  ],
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with tags

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text-tags.jsonld",
  "name": "Long-form text with tags",
  "url": "https://example.com/2024/11/07/long-form-text-tags.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is a long-form text object with tags.</p>",
  "content": "<p>@<a href='https://example.com/evan'>evan</a> made this #<a href='https://example.com/tag/example'>example</a>.</p>",
  "tag": [
    {
      "type": "Hashtag",
      "name": "example",
      "href": "https://example.com/tag/example"
    },
    {
      "type": "Mention",
      "href": "https://example.com/evan"
    }
  ],
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with context

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2024/11/07/long-form-text-context.jsonld",
  "name": "Long-form text with context",
  "url": "https://example.com/2024/11/07/long-form-text-context.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is a long-form text object with context.</p>",
  "content": "<p>This is a long-form text object with context.</p>",
  "context": [
    "https://example.com/2024/11/07/series",
    "https://example.com/2024/11/07/category"
  ],
  "published": "2024-11-07T12:00:00Z"
}

Long-form text with preview

{
  "@context": "https://www.w3.org/ns/activitystreams",
  "type": "Article",
  "id": "https://example.com/2025/02/17/long-form-text-preview.jsonld",
  "name": "Long-form text with preview",
  "url": "https://example.com/2025/02/17/long-form-text-preview.html",
  "attributedTo": "https://example.com/evan",
  "summary": "<p>This is the summary for a long-form text with a preview.</p>",
  "content": "<p>This is the content for a long-form text with a preview.</p>",
  "published": "2024-11-07T12:00:00Z",
  "image": {
    "type": "Link",
    "href": "https://example.com/image.jpg",
    "mediaType": "image/jpeg"
  },
  "preview": {
    "type": "Note",
    "attributedTo": "https://example.com/evan",
    "content": "<p><strong>Long-form text with preview</strong></p><p>This is the summary for a long-form text with a preview.</p><p><a href='https://example.com/2025/02/17/long-form-text-preview.html'>Read more</a></p>",
    "published": "2024-11-07T12:00:00Z",
    "attachment": {
      "type": "Link",
      "href": "https://example.com/image.jpg",
      "mediaType": "image/jpeg"
    }
  }
}

User interface guidance

Consumers should use their native interfaces to handle Article objects in an intuitive way that integrates well with other object types. The following illustrations provide examples of how Article objects might be displayed in a stream-oriented social web interface, such as a microblogging application. The UI elements are labelled with the properties of the Article object that most likely correspond to them.

In stream, with image

An example of a long-form text object with an image property displayed in a social stream.

Article in stream, with image

In stream, without image

An example of a long-form text object without an image property displayed in a social stream.

Article in stream, without image

In stream, no title

An example of a long-form text object without a name property displayed in a social stream.

Article in stream, no title

参考文献

James Snell, Evan Prodromou, Activity Streams 2.0, 2017
James Snell, Evan Prodromou, Activity Vocabulary, 2017
Christine Lemmer Webber, Jessica Tallon, ActivityPub, 2018
Dave Winer, RSS 2.0 Specification, 2003

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