Package 'metathis'

Title: HTML Metadata Tags for 'R Markdown' and 'Shiny'
Description: Create meta tags for 'R Markdown' HTML documents and 'Shiny' apps for customized social media cards, for accessibility, and quality search engine indexing. 'metathis' currently supports HTML documents created with 'rmarkdown', 'shiny', 'xaringan', 'pagedown', 'bookdown', and 'flexdashboard'.
Authors: Garrick Aden-Buie [aut, cre]
Maintainer: Garrick Aden-Buie <[email protected]>
License: MIT + file LICENSE
Version: 1.1.4.9000
Built: 2024-08-12 04:18:35 UTC
Source: https://github.com/gadenbuie/metathis

Help Index

Include Metadata Tags in HTML Document

Description

Use include_meta() to explicitly declare the meta() tags as an HTML dependency. In general, this is not required when knitting to an HTML document. This function explicitly attaches an htmltools::htmlDependency() and may work in some unusual cases.

Usage

include_meta(.meta)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.

Value

An htmltools::htmlDependency() containing the metadata tags to be included in the ⁠<head>⁠ of the HTML document.

See Also

Other meta_actions: write_meta()

Examples

meta() %>%
  meta_name("github-repo" = "gadenbuie/metathis") %>%
  include_meta()

Initialize a List of HTML Metadata Tags

Description

Initialize a metathis object (i.e. a list of HTML metadata tags), test if an object is a metathis object, or coerce a list of meta tags to be a metathis object.

Usage

meta()

is_meta(x)

as_meta(x)

Arguments

x

A list or metathis object

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

Functions

  • is_meta(): Test if an objects is a metathis object

  • as_meta(): Convert a list of meta tags into a metathis object.

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta_viewport()

Examples

meta() %>%
  meta_viewport() %>%
  is_meta()

list_of_meta_tags <- list(
  htmltools::tags$meta(github = "gadenbuie"),
  htmltools::tags$meta(twitter = "grrrck")
)

as_meta(list_of_meta_tags)

Apple Smart Banner Meta Tag

Description

Apple Smart Banner Meta Tag

Usage

meta_apple_itunes_app(.meta = meta(), app_id = NULL, affiliate_id = NULL, ...)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
app_id

Apple app ID
affiliate_id

Apple affiliate ID
...

Additional name=value pairs.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

Example

# <!-- Smart App Banner -->
<meta name="apple-itunes-app" content="app-id=APP_ID,affiliate-data=AFFILIATE_ID,app-argument=SOME_TEXT">

See Also

Other meta: meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta_viewport(), meta()

Apple Web App Meta Tags

Description

Apple Web App Meta Tags

Usage

meta_apple_web_app(
  .meta = meta(),
  title = NULL,
  capable = NULL,
  status_bar_style = c("default", "black", "black-translucent")
)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
title

Launch Icon Title
capable

Enables standalone (full-screen) mode if TRUE
status_bar_style

Status bar appearance. has no effect unless standalone more is enabled (see capable).

"If content is set to default, the status bar appears normal. If set to black, the status bar has a black background. If set to black-translucent, the status bar is black and translucent. If set to default or black, the web content is displayed below the status bar. If set to black-translucent, the web content is displayed on the entire screen, partially obscured by the status bar. The default value is default."

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

References

https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/MetaTags.html

See Also

Other meta: meta_apple_itunes_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta_viewport(), meta()

Examples

meta() %>%
  meta_apple_web_app(
    title = "My Fancy App",
    capable = TRUE,
    status_bar_style = "black-translucent"
  )

General Metadata Tags

Description

Generate metadata tags for general website properties.

Usage

meta_general(
  .meta = meta(),
  application_name = NULL,
  theme_color = NULL,
  description = NULL,
  robots = NULL,
  generator = NULL,
  subject = NULL,
  rating = NULL,
  referrer = NULL
)

meta_description(.meta = meta(), description)

meta_subject(.meta = meta(), subject)

meta_referrer(.meta = meta(), referrer)

meta_robots(.meta = meta(), robots)

meta_theme_color(.meta = meta(), theme_color)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
application_name

Name of web application (only should be used if the website is used as an app).
theme_color

Theme Color for Chrome, Firefox OS and Opera, e.g. "#00589a".
description

Short description of the document (limit to 150 characters), This content may be used as a part of search engine results.
robots

Control the behavior of search engine crawling and indexing, e.g. "index,follow". Valid names are "index", "noindex", "follow", "nofollow". May be a vector or a single string with comma-separated values.

See https://www.robotstxt.org/meta.html for more information.
generator

Identify the software used to build the document (i.e. - WordPress, Dreamweaver).
subject

Short description of your document's subject.
rating

Gives a general age rating based on the document's content, e.g. "General".
referrer

Allows control over how referrer information is passed, .e.g. "no-referrer". Valid values include "no-referrer", "no-referrer-when-downgrade", "same-origin", "origin", "strict-origin", "origin-when-cross-origin", "strict-origin-when-cross-origin", or "unsafe-url".

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta_viewport(), meta()

Examples

meta() %>%
  meta_general(
    application_name = "Application Name",
    theme_color = "#4285f4",
    description = "A description of this page",
    robots = "index,follow",
    generator = "R-Shiny",
    subject = "Awesome R projects",
    rating = "General",
    referrer = "no-referrer"
  )

Geotagging Metadata Tags

Description

Geotagging Metadata Tags

Usage

meta_geo(
  .meta = meta(),
  icbm = NULL,
  geo_position = NULL,
  geo_region = NULL,
  geo_placename = NULL,
  ...
)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
icbm

Latitude and longitude of geographic positions specified as "lat, long". Can optionally be a length-two vector, i.e. c(lat, long).
geo_position

Latitude and longitude of geographic positions specified as "lat;long". Can optionally be a length-two vector, i.e. c(lat, long).
geo_region

Name of the geographic region related to the page content, specified using ISO-3166 2-character country code and 2-character national subdivision. Example: "US-NY".
geo_placename

Name of the geographic place related to the page content. Example: "Atlanta, Georgia".
...

Additional geotagging metadata keyword and value pairs, such as geo.country, geo.a1, ..., geo.a3, etc. Underscores in the keyword will be converted to periods, so you can also specify geo_country in place of geo.country.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

References

ICBM on Wikipedia, Geotagging on Wikipedia

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta_viewport(), meta()

Examples

meta() %>%
  meta_geo(
    icbm = c(50.167958, -97.133185),
    geo_position = c(50.167958, -97.133185),
    geo_placename = "Manitoba, Canada",
    geo_region = "ca-mb"
  )

Add Google Scholar Metadata

Description

Add bibliographic metadata to pages in the format expected by Google Scholar. Please reference the Google Scholar Inclusion page for the most up-to-date information and instructions. Note that this function adds the citation_ prefix to all of its arguments; the title argument becomes the citation_title ⁠<meta>⁠ tag.

Usage

meta_google_scholar(
  .meta = meta(),
  title,
  author,
  publication_date,
  online_date = NULL,
  journal_title = NULL,
  conference_title = NULL,
  volume = NULL,
  issue = NULL,
  firstpage = NULL,
  lastpage = NULL,
  pdf_url = NULL,
  issn = NULL,
  isbn = NULL,
  dissertation_institution = NULL,
  technical_report_institution = NULL,
  technical_report_number = NULL
)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
title

The title of the paper.

The title tag must contain the title of the paper. Don't use it for the title of the journal or a book in which the paper was published, or for the name of your repository. This tag is required for inclusion in Google Scholar.
author

A vector of author names.

The author tag, must contain the authors (and only the actual authors) of the paper. Don't use it for the author of the website or for contributors other than authors, e.g., thesis advisors. Author names can be listed either as "Smith, John" or as "John Smith". Put each author name in a separate tag and omit all affiliations, degrees, certifications, etc., from this field. At least one author tag is required for inclusion in Google Scholar.
publication_date, online_date

The date the paper was published in the journal (publication_date) or published online (online_date).

The publication_date tag must contain the date of publication, i.e., the date that would normally be cited in references to this paper from other papers. Don't use it for the date of entry into the repository - that should go into online_date instead. Provide full dates in the "2010/5/12" format if available; or a year alone otherwise. This tag is required for inclusion in Google Scholar.
journal_title, conference_title, issn, isbn, volume, issue, firstpage, lastpage

For journal and conference papers, provide the remaining bibliographic citation data in the following tags: journal_title or conference_title, issn, isbn, volume, issue, firstpage, and lastpage. These fields must contain sufficient information to identify a reference to this paper from another document, which is normally all of: (a) journal or conference name, (b) volume and issue numbers, if applicable, and (c) the number of the first page of the paper in the volume (or issue) in question.
pdf_url

The ⁠<meta>⁠ tags normally apply only to the exact page on which they're provided. If this page shows only the abstract of the paper and you have the full text in a separate file, e.g., in the PDF format, please specify the locations of all full text versions using pdf_url. The content of the tag is the absolute URL of the PDF file; for security reasons, it must refer to a file in the same subdirectory as the HTML abstract.
dissertation_institution, technical_report_institution, technical_report_number

For theses, dissertations, and technical reports, provide the remaining bibliographic citation data in the following tags: dissertation_institution, technical_report_institution for the name of the institution and technical_report_number for the number of the technical report. As with journal and conference papers, you need to provide sufficient information to recognize a formal citation to this document from another article.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

References

https://scholar.google.com/intl/en/scholar/inclusion.html#indexing

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_name(), meta_social(), meta_tag(), meta_viewport(), meta()

Examples

meta_google_scholar(
  title = c(
    "The testis isoform of the phosphorylase kinase catalytic subunit (PhK-T)",
    "plays a critical role in regulation of glycogen mobilization in developing lung"
  ),
  author = c(
    "Liu, Li",
    "Rannels, Stephen R.",
    "Falconieri, Mary",
    "Phillips, Karen S.",
    "Wolpert, Ellen B.",
    "Weaver, Timothy E."
  ),
  publication_date = "1996/05/17",
  journal_title = "Journal of Biological Chemistry",
  volume = 271,
  issue = 20,
  firstpage = 11761,
  lastpage = 11766,
  pdf_url = "http://www.example.com/content/271/20/11761.full.pdf"
)

Create name/content metadata tag pairs

Description

Creates metadata tag pairs where the arguments are the name values and their values are content values.

Usage

meta_name(.meta = meta(), ...)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
...

Name (argument names) and content (argument value) pairs.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_social(), meta_tag(), meta_viewport(), meta()

Examples

meta() %>%
  meta_name("github-repo" = "hadley/r4ds")

Social Media Metadata

Description

Generate metadata tags for social media cards.

Usage

meta_social(
  .meta = meta(),
  title = NULL,
  url = NULL,
  image = NULL,
  image_alt = NULL,
  image_width = NULL,
  image_height = NULL,
  description = NULL,
  twitter_card_type = c("summary", "summary_large_image", "app", "player"),
  twitter_creator = NULL,
  twitter_site = twitter_creator,
  og_type = "website",
  og_locale = "en_US",
  og_author = NULL,
  og_site_name = NULL,
  facebook_app_id = NULL,
  disable_pinterest = FALSE
)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
title

Content title
url

Content URL
image

Image url for card.
image_alt

A description of what's in the image (not a caption)
image_width

The width of the image in pixels
image_height

The height of the image in pixels
description

Content description. If you have already used meta_general() to set the content's description, that description will automatically be used.
twitter_card_type

One of "summary", "summary_large_image", "app", or "player".
twitter_creator

⁠@username⁠ for the content creator / author.
twitter_site

⁠@username`` for the website used in the card footer. ⁠twitter_creator' is used by default.
og_type

Open Graph card type, default is "website". Other common options include "article", "book", or "profile". The full list of valid options can be referenced at https://ogp.me/
og_locale

The locale these tags are marked up in. Of the format language_TERRITORY. Default is "en_US".
og_author

Writers of the article. Multiple authors may be specified in a vector of character strings.
og_site_name

The name of the site hosting the content
facebook_app_id

The Facebook app ID. See the Facebook Open Graph Markup page for more information.
disable_pinterest

If TRUE, adds a metadata tag disabling pins from your website. See the Pinterest help center for more information.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

References

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_tag(), meta_viewport(), meta()

Examples

meta() %>%
  meta_social(
    title = "R for Data Science",
    description = "This book with teach you how to do data science with R",
    url = "https://r4ds.had.co.nz",
    image = "https://r4ds.had.co.nz/cover.png",
    image_alt = "The cover of the R4DS book",
    og_type = "book",
    og_author = c("Garrett Grolemund", "Hadley Wickham"),
    twitter_card_type = "summary",
    twitter_creator = "@hadley"
  )

Create a metadata tag for attribute/value pairs

Description

Creates a ⁠<meta>⁠ tag for attribute value pairs, where argument names correspond to attribute names.

Usage

meta_tag(.meta = meta(), ...)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
...

Attribute names and values as attribute = value. Values must be a single character string.

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_viewport(), meta()

Examples

meta() %>%
  meta_tag(
    "http-equiv" = "Content-Security-Policy",
    content = "default-src 'self'"
  )

Viewport Meta Tag

Description

Create or add a viewport meta tag.

Usage

meta_viewport(
  .meta = meta(),
  width = "device-width",
  initial_scale = "1",
  orientation = c("auto", "portrait", "landscape"),
  min_width = NULL,
  max_width = NULL,
  height = NULL,
  min_height = NULL,
  max_height = NULL,
  minimum_scale = NULL,
  maximum_scale = NULL,
  user_scalable = NULL,
  ...
)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
width

Sets the width of initial viewport. width sets min_width and max_width and may contain two values; for example, the following are equivalent: "300px 500px" or c("300px", "500px")). The values may be a number with units, a percentage, or "device-width". Pixels are assumed if no units are provided.
initial_scale

Initial scale
orientation

One of "auto", "portrait", "landscape".
min_width, max_width

Minimum and maximum initial viewport width. See width for more information. width is ignored if min_width or max_width are set.
height, min_height, max_height

Sets height of initial viewport. Follows the same conventions as width, min_width, and max_width.
minimum_scale

Minimum scale
maximum_scale

Maximum scale
user_scalable

User scalable
...

Additional name/value pairs

Value

A meta object, or a set of ⁠<meta>⁠ HTML tags inside an HTML ⁠<head>⁠ tag. For use in rmarkdown::html_document(), shiny::runApp(), or other HTML locations.

References

MDN: Viewport Meta Tag,

See Also

Other meta: meta_apple_itunes_app(), meta_apple_web_app(), meta_general(), meta_geo(), meta_google_scholar(), meta_name(), meta_social(), meta_tag(), meta()

Examples

meta() %>%
  meta_viewport()

meta() %>%
  meta_viewport(orientation = NULL)

meta() %>%
  meta_viewport(maximum_scale = 1)

Write Metadata Tags to a File

Description

Write your metadata tags to an HTML file that can be manually included in your page.

Usage

write_meta(.meta, path = "meta.html", append = FALSE)

Arguments

.meta

A meta object created by meta() or as_meta(), or returned by a ⁠meta_*()⁠ object.
path

The file to write into, defaults to "meta.html".
append

logical. Only used if the argument file is the name of file (and not a connection or "|cmd"). If TRUE output will be appended to file; otherwise, it will overwrite the contents of file.

Value

Returns .meta invisibly.

See Also

Other meta_actions: include_meta()

Examples

meta_html_snippet <- tempfile("metathis_example", fileext = ".html")

meta() %>%
  meta_name("package" = "metathis") %>%
  write_meta(meta_html_snippet)

readLines(meta_html_snippet, warn = FALSE)