R xaringan construct footer to include title/author automatically - r

I use xaringan to create a presentation (with a footer).
The footer should include the title, and probably also the author of the presentation automatically.
To get the current slide number, I can use %current%, but %title% or %author$ fails. I know I can access the metadata like so in R rmarkdown::metadata$title, but I fail to construct the slideNumberFormat using R. I.e., r cat('<div class = "remark-slide-number-left">', rmarkdown::metadata$title, '</div>') does not work.
Any ideas?
MWE:
---
title: "Minimal Presenation"
author: "The Author"
output:
xaringan::moon_reader:
nature:
slideNumberFormat: '<div class = "remark-slide-number-left"> %title% - %current%</div>'
---
# Hello World
here %title% does not work, the intended output format would be "Minimal Presentation".
The alternative (which also does not work) would be to construct the footer using R similar to this
slideNumberFormat: "`r cat('<div class = \"remark-slide-number-left\">', rmarkdown::metadata$title, ' - %current% </div>')`"

With the help of some non-SO people, I was able to find this answer.
The only drawback is, that it does not construct the footer in one element, but internally constructs two footers... Nonetheless, it allows the reuse of the author and title and other YAML elements.
The css style of the footer can (and should be) written to a css file similar to what #persephone did.
---
title: "Minimal Presentation"
author: "The Author"
output:
xaringan::moon_reader:
css: ["default"]
nature:
slideNumberFormat: "%current%"
---
layout: true
<div style="position: absolute;left:60px;bottom:11px;color:gray;">`r rmarkdown::metadata$author` - `r rmarkdown::metadata$title`</div>
---
# Hello World
First content slide
---
class: inverse, center, middle
# Section Header
---
# Foo Bar
Second content slide

In general, I am not a huge fan of footers in presentations (they are mostly useless IMO/add unnecessary visual cluttering). However, some co-authors prefer to have them in conference presentations.
I also fiddled around with automatization but didn't find a perfect solution without putting much work into it.
Thus, my approach was to leave the slide numbering as is and just hardcode an extra footer with Authors/etc.
Add to a custom .css/style file/tweak to your needs:
div.footer {
background-color: #5c6266;
position: absolute;
bottom: 10px;
left: 0px;
height: 25px;
width: 20%;
}
div.footer span {
font-size: 13pt; /* */
color: #f6f3f2;
position: absolute;
left: 15px;
bottom: 1px;
}
Source it in your YAML:
css: ["default", custom.css"]
Add/Tweak this just before the 1st slide you want to include your footer in (e.g. after your title slide):
---
layout:true
<div class="footer"><span>John Doe et al.</span></div>
---
This is hacky but does not break the slide numbering and was the fastest solution I came up with in my context.

Related

How can I add arbitrary elements to the Table of Contents in Bookdown?

I am making a book via bookdown.
I know it is possible to omit headings from the Table of Contents by adding the attributes {.unlisted .unnumbered}, as shown in Section 4.18 of the R Markdown Cookbook.
However, how can I add arbitrary content to the Table of Contents?
If I only needed to add this for the PDF output, I could use (e.g.) the LaTeX command \addcontentsline, but I need this to show in the HTML contents sidebar as well.
For example, if you set up a new default bookdown project from RStudio, it includes the file 01-intro.Rmd.
The first few lines are
# Introduction {#intro}
You can label chapter and section titles using `{#label}` after them, e.g., we can reference Chapter \#ref(intro). If you do not manually label them, there will be automatic labels anyway, e.g., Chapter \#ref(methods).
Figures and tables with captions will be placed in `figure` and `table` environments, respectively.
I need to be able to create arbitrary divs that are added to the table of contents, like so:
# Introduction {#intro}
You can label chapter and section titles using `{#label}` after them, e.g., we can reference Chapter \#ref(intro). If you do not manually label them, there will be automatic labels anyway, e.g., Chapter \#ref(methods).
::: {#arbitrary-header <some other attribute?>}
Figures and tables with captions will be placed in `figure` and `table` environments, respectively.
:::
Which would add the sentence "Figures and tables with captions will be placed in figure and table environments, respectively." in both the LaTeX Table of Contents and the sidebar on the HTML output.
The context of this problem is that I need to place a header inside another custom div that formats the content within a colorbox to make it stand out.
Otherwise, I could of course just add another heading via ## before the sentence above.
We could use an R function that prints a colored box and adds the title to the TOC depending on the output format. For gitbook output, this is easily done using HTML and markdown. For pdf_book we may use a LaTeX environment for colored boxes like tcolorbox.
Here is the function (define in a code block in .Rmd file):
block_toc <- function(title, level, content, output) {
if(output == "html") {
title <- paste(paste(rep("#", level), collapse = ""), title, "{-}")
cat('<div class = "myblock">', title, '<p>', content, '</p>\n</div>', sep = "\n")
} else {
level <- c("part", "chapter", "section")[level]
cat('\\addcontentsline{toc}{', level, '}{', title, '}',
'\n\\begin{mybox}\n\\textbf{\\noindent ', title, '}\n\\medskip\n\n', content,
'\n\n\\end{mybox}', sep = "")
}
}
Depending on the output format, block_toc() concatenates and prints the code for the blocks and, of course, also ensures that the title is added to the TOC. You can set the level of the TOC where the box title is added using level.
Use block_toc() like this in a chunk:
```{r, results='asis', echo=F, eval=T}
block_toc(
title = "Central Limit Theorem",
level = 2
content = "The CLT states that, as $n$ goes to infinity,
the sample average $\\bar{X}$ converges in distribution
to $\\mathcal{N}(\\mu,\\sigma^2/n)$.",
output = knitr::opts_knit$get("rmarkdown.pandoc.to")
)
```
output = knitr::opts_knit$get("rmarkdown.pandoc.to") will get and pass the current output format to the function when building the book.
Some styles for appealing boxes
Add to preamble.tex (for colored box in PDF output -- include file in YAML header). This will define a tcolorbox environment for generating blue boxes.
\usepackage{tcolorbox}
\definecolor{blue}{HTML}{D7DDEF}
\definecolor{darkblue}{HTML}{2B4E70}
\newtcolorbox{mybox}{colback=blue, colframe=darkblue}
Add to style.css (styles for HTML colored box) or include in a ```{css} code chunk:
.myblock {
background-color: #d7ddef;
border: solid #2b4e70;
border-radius: 15px;
}
.myblock p, .myblock h2, .myblock h3 {
padding: 5px 5px 5px 20px;
margin-top: 0px !important;
}
For HTML output (gitbook) this yields
and for LaTeX output (pdf_book) it looks like this
with a corresponding entry at the section level in the TOC.
Maybe this solution?
CSS-file:
k1 {
font-family: 'Times New Roman', Times, serif;
font-size: 12pt;
text-align: justify;
}
#TOC {
color:black;
background-color: white;
position: fixed;
top: 0;
left: 0;
width: 250px;
padding: 10px;
overflow:auto;
margin-left: -5px;
}
body {
max-width: 800px;
margin-left:300px;
line-height: 20px;
}
div#TOC li {
list-style:none;
}
h2#toc-title {
font-size: 24px;
color: Red;
}
Rmd-file:
---
title: "Arbitrary elements"
author: "Me"
date: "`r Sys.Date()`"
output:
bookdown::html_document2:
toc: true
css: "arb.css"
toc-title: "Contents"
---
# My question is it: "..."
# Introduction of our story ...
# It was a strange person ...
## The Flame was in his body ...
# <k1> Figures and tables with captions will be placed in `figure` and `table` environments, respectively. </k1> {-}
## Where is the love, friends?
We'll be using a Lua filter for this, as those are a good way to modify R Markdown behavior. The "Bookdown Cookbook" has an excellent overview and includes a description of how to use Lua filters.
The way we are doing this is to side-step the normal TOC generator and rewrite it in Lua. Then we add our new TOC as a meta value named table-of-contents (and toc, for compatibility), which is enough to be included in the output.
So first let's dump the code to create a normal TOC:
_ENV = pandoc
local not_empty = function (x) return #x > 0 end
local section_to_toc_item
local function to_toc_item (number, text, id, subcontents)
if number then
text = Span({Str(number),Space()} .. text, {class='toc-section-number'})
end
local header_link = id == '' and text or Link(text, '#' .. id)
local subitems = subcontents:map(section_to_toc_item):filter(not_empty)
return List{Plain{header_link}} ..
(#subitems == 0 and {} or {BulletList(subitems)})
end
section_to_toc_item = function (div)
-- bail if this is not a section wrapper
if div.t ~= 'Div' or not div.content[1] or div.content[1].t ~= 'Header' then
return {}
end
local heading = div.content:remove(1)
local number = heading.attributes.number
-- bail if this is not supposed to be included in the toc
if not number and heading.classes:includes 'unlisted' then
return {}
end
return to_toc_item(number, heading.content, div.identifier, div.content)
end
-- return filter
return {
{ Pandoc = function (doc)
local sections = utils.make_sections(true, nil, doc.blocks)
local toc_items = sections:map(section_to_toc_item):filter(not_empty)
doc.meta['table-of-contents'] = {BulletList(toc_items)}
doc.meta.toc = doc.meta['table-of-contents']
return doc
end
},
}
The code makes a few minor simplifications, but should produce an identical TOC for most documents. Now we can go on and modify the code to our liking. For example, to include divs with the class toc-line, the section_to_toc_item could be modified by adding this code at the start of the function:
section_to_toc_item = function (div)
if div.t == 'Div' and div.classes:includes('toc-line') then
return to_toc_item(nil, utils.blocks_to_inlines(div.content), div.identifier)
end
⋮
end
Modify the code as you see fit.
Also, if you want to exclude the extra TOC lines from the normal output, you'll have to filter them out. Let the script return a second filter to do that:
return {
{ Pandoc = function (doc) ... end },
{ Div = function (div) return div.classes:includes 'toc-line' and {} or nil end }
}

YAML title font and color in Rmarkdown

Is there a way to change the font and color in the YAML title in a R markdown flexdashboard?
Here is the code for the YAML header I am trying to change:
---
title: "Greenhouse gases and weather data"
fontsize: 30
output:
flexdashboard::flex_dashboard:
orientation: rows
vertical_layout: fill
social: menu
source_code: embed
theme: readable
---
The other option would be to add a CSS code chunk anywhere in the dashboard
```{css}
body > div.navbar.navbar-inverse.navbar-fixed-top > div > div.navbar-header > span.navbar-brand {
font-size: 26px;
color: red;
}
```
as Kat said, the color is set by CSS , therefore you can change the behaviour in the .rmd file itself, or in the underlying theme template .css file.
somewhere located at:
/home/user/R/x86_64-pc-linux-gnu-library/4.0/flexdashboard/rmarkdown/templates/flex_dashboard/resources
add (to the rmd) or look for and change (the .css) to :
<style>
.navbar {
background-color:white;
border-color:blue;
}
.navbar-brand {
color:blue!important;
}
</style>
This will revert the default color scheme of the top navbar
at the moment i dont know a simple YAML - argument solution for this
( but looking into css will gain you much more
versatility along the way, than relying on the YAML options)

how to number custom blocks in R markdown [duplicate]

Is there an option I can provide to code chunks in RMarkdown so that it will have a cell number attached to the HTML output. Much like Jupyter has cell numbers.
I've seen some example with line numbering which is not what I want.
Using cell numbers is helpful when I'm discussing an RMarkdown HTML file over the phone with someone. I can ask him/her to see cell 23. I have a lot of R code, so providing section titles, while possible, is tedious.
Here's a solution using only CSS. It relies on CSS counters: each new R chunk increments the counter (named counter-rchunks).
You can knit the following minimal Rmd file and get this result:
---
title: "Counter for chunks"
author: "Romain Lesur"
output: html_document
---
```{css, echo=FALSE}
body {
counter-reset: counter-rchunks;
}
div.main-container {
padding-left: 5em;
}
pre.r {
counter-increment: counter-rchunks;
position: relative;
overflow: visible;
}
pre.r::before {
content: 'In [' counter(counter-rchunks) ']: ';
display: inline-block;
position: absolute;
left: -5em;
color: rgb(48, 63, 159);
}
```
```{r cars}
summary(cars)
```
```{r head-cars}
head(cars)
```
You may have to adapt this solution to your HTML template.
You also can insert these CSS rules to a .css file and includes it in your html_document.

R markdown: how to change style with internal css?

I know how to change R markdown style with a custom css file. However, when the changes are minor, I prefer internal or even inline css, to save trouble from managing two files. I googled and haven't find a solution for this. Below is a simple example of changing style with an external css file. Is there a way to do it with internal or inline css?
The R markdown file:
---
title: "test"
output:
html_document:
css: test.css
---
## Header 1 {#header1}
But how to change style with internal css?
The test.css file:
#header1 {
color: red;
}
Markdown accepts raw HTML and passes it through unaltered, so define your "styled" elements as HTML:
<h2 style="color: red;">Header 1</h2>
Of course, some tools don't actually allow the raw HTML to be passed through (for security reasons or because the final output is not HTML), so your mileage may vary.
Depending on the Markdown implementation you are using, you may be able to define styles in the attribute list (if it supports arbitrary keys):
## Header 1 {style="color: red;"}
However, that is the least likely to work.
And remember, HTML <style> tags do not need to be in the document <head> to work. If you can use raw HTML, you can include a <style> element in the body of your document (as pointed out by #user5219763 in a comment):
---
title: "test"
output:
html_document
---
<style>
#header1 {
color: red;
}
</style>
## Header 1 {#header1}
But how to change style with internal css?
If you don't want to create an external .css file, but would like to define several styles and would rather keep your code less crowded, another possibility is to use a css chunk at the beginning of your R markdown:
---
title: "test"
output: html_document
---
```{css, echo = FALSE}
#header1 {
color: red;
}
```
## Header 1 {#header1}
In the css chunk, you can control multiple styles, as you would do in an external .css file.
Another, sort of hacky option is to specify a css file in the script, then create it in the first chunk.
e.g. the first 18 lines of your .Rmd file:
---
title: "Something Important"
output:
html_document:
css: mystyle.css
---
```{r b, echo=F}
writeLines("td, th { padding : 6px }
th { background-color : coral ;
color : white;
border : 1px solid white; }
td { color : black ;
border : 1px solid skyblue }
h1, h2, h3, h4, h5, p { font-family: consolas; ",
con = "mystyle.css")
```
In the above, I first reference the file mystyle.css in the header block of markdown. Then, I create the file using writeLines(), and save it to the file specified with con = ....
Personally, I think the best option is to just throw your code in between some <script></script> tags if it's a one-off R script.
However, if you do want to create an external file, but don't want to edit a separate file, the above method provides a workaround. It just feels odd.

Adding custom CSS tags to an RMarkdown html document

I have an RMarkdown document outputting to HTML of the same form as the below example. What do I add where to apply unique CSS ids or classes to each plot output?
---
title: "RMarkdown"
author: "Me"
date: "Friday, March 27, 2015"
output:
html_document:
theme: null
css: style.css
---
```{r plot1, echo=FALSE, warning=FALSE, message=FALSE}
library(ggplot2)
x <- ggplot(some_r_code)
print(x)
```
```{r plot2, echo=FALSE, warning=FALSE, message=FALSE}
y <- ggplot(some_more_r_code)
print(y)
```
I've read the info page at http://rmarkdown.rstudio.com/html_document_format.html that went a ways to answering this question but didn't get me there. I have a similar question referencing the material in that page in it's comment section, and would appreciate an answer on either.
Thanks!
You can tell knitr (which is used under the hood) with results="asis" to embed a chunk's output directly into the html. Within the chunk you can use cat to simply write a style tag including your css definitions:
```{r results="asis"}
cat("
<style>
h1 {
color: red;
}
</style>
")
```
See http://yihui.name/knitr/options/#chunk_options for details.
Declaring custom css in RMarkdown
Add css between <style> and </style> tags in the regular body of the RMarkdown (i.e. not in R code area), like so:
<style>
.pad {
padding-top: 200px;
}
</style>
# This heading will be padded {.pad}
Another option is to declare css: "style.css" in yaml and store styles in a separate file (style sheet) in the same directory
Or css can be generated and applied via R code (excellent example here)
Open the resultant HTML in a browser with a Developer Tools option and look at the generated HTML. Then apply you styling to the appropriate tags/classes. For example, put the following into style.css, knit the file and you should see a red border on the plots:
img {
background-color: red;
padding: 2px;
border: 1px solid red;
border-radius: 3px;
margin: 0 5px;
max-width: 100%;
}

Resources