fedi2html/fedi2html.sh
Jaidyn Ann c5e9a5bc93 Support rendering of user-URLs
That is, rendering recent posts from a user’s
profile!
2024-04-03 18:32:05 -05:00

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#!/bin/sh
#―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
# Name: fedi2html.sh
# Desc:
# Reqs:
# Date:
#―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
POST_TEMPLATE='
<article class="comment">
<a class="user" href="$ACCOUNT_URL">
<img class="avatar" src="$ACCOUNT_AVATAR">
<strong class="username">$ACCOUNT_NAME</strong>
<em class="useraddress">$ACCOUNT_ID</em>
</a>
<a class="address" href="$POST_URL">
<time title="$POST_DATE">$(date --date=$POST_DATE)</time>
</a>
<section>
$POST_CONTENT
</section>
<div class="attachments">
$POST_ATTACHMENTS
</div>
<div class="responses">
$POST_RESPONSES
</div>
</article>
'
ATTACH_TEMPLATE='
<a href="$ATTACH_URL">
<div class="attachment">
<strong>$ATTACH_NAME</strong>
$ATTACH_DESC
</div>
</a>'
ATTACH_IMAGE_TEMPLATE='
<figure>
<a href="$ATTACH_URL">
<img class="attachment" src="$ATTACH_URL" alt="$ATTACH_DESC" title="$ATTACH_DESC">
</a>
<figcaption>
<a href="$ATTACH_URL"><b>$ATTACH_NAME</b></a><br>
$(if test $(echo "$ATTACH_DESC" | wc -c) -gt 52; then
echo $ATTACH_DESC | head -c 53 | sed 's%[[:space:]]*$%%'
echo …
else
echo $ATTACH_DESC
fi)
</figcaption>
</figure>
'
EMOJI_TEMPLATE='<img class="emoji" src="$EMOJI_URL" alt="$EMOJI_SHORTCODE" title="$EMOJI_SHORTCODE">'
# Given a notes JSON, render it as HTML.
# The most important part of the script!
# render_post $post_data $context_data $tree_level
render_post() {
local post_data="$1"
local responses_data="$2"
local POST_TREE_LEVEL="$3"
local reblog=""
local acct_data="$(echo "$post_data" | jq -r .reblog.account)"
if test "$acct_data" = "null"; then
acct_data="$(echo "$post_data" | jq -r .account)"
else
reblog="1"
fi
local ACCOUNT_URL="$(echo "$acct_data" | jq -r .url)"
local ACCOUNT_ID="$(echo "$acct_data" | jq -r .fqn)"
local ACCOUNT_NAME="$(echo "$acct_data" | jq -r .display_name | replace_emojis "$acct_data")"
local ACCOUNT_AVATAR="$(echo "$acct_data" | jq -r .avatar)"
local POST_URL="$(echo "$post_data" | jq -r .url)"
local POST_DATE="$(echo "$post_data" | jq -r .created_at)"
local POST_CONTENT="$(echo "$post_data" | jq -r .content | replace_emojis "$post_data")"
local POST_ATTACHMENTS="$(media_attachments "$post_data")"
if test -z "$NO_RESPONSES"; then
local POST_RESPONSES="$(render_responses "$post_data" "$responses_data" "$POST_TREE_LEVEL")"
fi
env_subst "$POST_TEMPLATE"
}
# Render a posts responses one-by-one and recursively.
# Each branch of the response tree will be rendered completely before proceeding
# to the next.
# render_responses $post_data $context_data $tree_level
render_responses() {
local post_data="$1"
local responses_data="$2"
local level="$3"
if test -z "$level"; then level=0; fi
local id="$(echo "$post_data" | jq -r '.id')"
local responses="$(echo "$responses_data" | grep "in_reply_to_id.*$id")"
local IFS="
"
for response in $responses; do
render_post "$response" "$responses_data" "$(expr "$level" + 1)"
done
}
# Accepts a string over stdin; it will replace all emoji shortcodes along stdin
# input with appropriate <img> HTML, based on $EMOJI_TEMPLATE, and based on
# a posts JSON.
# echo ":blobcat:" | replace_emojis $post_data
replace_emojis() {
local post_data="$1"
local emojis="$(echo "$post_data" | jq -r '.emojis[]|(.url + "\t" + .shortcode)')"
local temp="$(mktemp)"
local IFS="
"
cat > "$temp"
for line in $emojis; do
local EMOJI_URL="$(echo "$line" | awk -F'\t' '{print $1}')"
local EMOJI_SHORTCODE="$(echo "$line" | awk -F'\t' '{print $2}')"
local value="$(env_subst "$EMOJI_TEMPLATE")"
sed -i "s%:${EMOJI_SHORTCODE}:%${value}%g" "$temp"
done
cat "$temp"
rm "$temp"
}
# Given a posts JSON data, return the appropriate HTML corresponding to its
# media attachments, if any. Will return an empty string if none.
# media_attachments $post_data
media_attachments() {
local post_data="$1"
local attachments="$(echo "$post_data" | jq -r '.media_attachments[]|(.type + "\t" + .url + "\t" + .description + "\t" + .preview_url)')"
local IFS="
"
for line in $attachments; do
local ATTACH_TYPE="$(echo "$line" | awk -F'\t' '{print $1}')"
local ATTACH_URL="$(echo "$line" | awk -F'\t' '{print $2}')"
local ATTACH_DESC="$(echo "$line" | awk -F'\t' '{print $3}')"
local ATTACH_PREVIEW="$(echo "$line" | awk -F'\t' '{print $4}')"
local ATTACH_NAME="$(basename "$ATTACH_URL")"
if test "$ATTACH_TYPE" = "image"; then
env_subst "$ATTACH_IMAGE_TEMPLATE"
else
env_subst "$ATTACH_TEMPLATE"
fi
done
}
# Pass a posts context JSON along stdin; out comes the response_data in JSON.
# fetch_post_context $url | context_to_responses
context_to_responses() {
jq '.descendants' 2> /dev/null \
| jq 'sort_by(.created_at)' \
| maybe_jq_reverse \
| jq -cr '.[]'
}
# Make a request to the /api/v1/statuses/:id/$request API endpoint.
# statuses_api_request $post_url $request
statuses_api_request() {
local post_url="$1"
local api_request="$2"
if test -n "$api_request"; then
api_request="/$api_request"
fi
local id="$(url_post_id "$post_url")"
local server="$(url_server "$post_url")"
curl --location --header 'Accept: application/json,application/activity+json' \
"${server}/api/v1/statuses/${id}${api_request}"
}
# Require the context-JSON of a post, by URL.
# fetch_post_context $url
fetch_post_context() {
local url="$1"
statuses_api_request "$url" "context" \
| context_to_responses
}
# Given a post URL, request its JSON.
# fetch_post $url
fetch_post() {
local url="$1"
statuses_api_request "$url"
}
# Given a user-account URL, request JSON of its posts.
# fetch_post $url
fetch_user_posts() {
local url="$1"
local server="$(url_server "$url")"
curl --location --header 'Accept: application/json,application/activity+json' \
"$server/api/v1/accounts/$(url_user_id "$url")/statuses?exclude_reblogs" \
| jq -c '.[]'
}
# Return the ID of a user, based on its URL.
# url_user_id $url
url_user_id() {
local url="$1"
# Pleroma-style URLs: https://jam.xwx.moe/users/Tirifto
# Mastodon-style URLs: https://esperanto.masto.host/@jubiloEO
if echo "$url" | grep "/users/" > /dev/null; then
echo "$url" \
| sed 's%.*/users/%%'
elif echo "$url" | grep -E "/@[[:alnum:]]+[/]*$" > /dev/null; then
echo "$url" \
| sed 's%.*/@%%' \
| sed 's%/$%%'
else
return 1
fi
}
# Return the ID of a post, based on its URL.
# url_post_id $url
url_post_id() {
local url="$1"
# Pleroma-style URLs: https://jam.xwx.moe/notice/Ac6PIZAP0ZzkMTYBBg
# Mastodon-style URLs: https://esperanto.masto.host/@minjo/111461250815264185
if echo "$url" | grep "/notice/" > /dev/null; then
echo "$url" \
| sed 's%.*/notice/%%'
elif echo "$url" | grep -E "/@[[:alnum:]]+/[[:digit:]]+" > /dev/null; then
echo "$url" \
| sed 's%.*/@[[:alnum:]]*/%%'
else
return 1
fi
}
# Return the server (including protocol) of a post, based on its URL.
# url_server $url
url_server() {
local url="$1"
local protocol="$(echo "$url" | grep --only-matching '[[:alnum:]]*://')"
printf "$protocol"
echo "$url" \
| sed 's%^'"$protocol"'%%' \
| sed 's%/.*%%'
}
# Sanitize a template-string.
# AKA, escape quotation-marks.
# prep_template $template
prep_template() {
local template="$1"
echo "$template" \
| sed 's%\"%\\\"%g'
}
# Rough replacement for gettexts envsubst. Safe!
# This will evaluate a strings shell variables (somewhat) safely
# Probably not good for general use — but for our purposes, it only subsitutes
# along the “first level.” So environment variables are replaced, but those
# variables contents (AKA, post contents) arent evaluated.
# env_subst $template
# env_subst "$SHELL" → "/bin/sh"
env_subst() {
local template="$1"
eval "echo \"$(prep_template "$template")\""
}
# Based on the environment variable $REVERSE_ORDER (whether or not user provided
# the -I flag), reverse the JSON array over stdin.
# This is used to enable/disable reverse-chronological order of posts.
# fetch_context $url | jq '.descendants' | maybe_jq_reverse
maybe_jq_reverse() {
local input="$(cat)"
if test -n "$REVERSE_ORDER"; then
echo "$input" \
| jq 'reverse'
else
echo "$input"
fi
}
# Render a users posts, one-by-one, taking into account cli arguments.
# handle_user_url https://jam.xwx.moe/users/tirifto
handle_user_url() {
local url="$1"
local user_posts="$(fetch_user_posts "$url")"
local IFS="
"
echo "$user_posts" > jadedctrl.json
for post in $user_posts; do
local url="$(echo "$post" | jq -r '.url')"
if test -z "$NO_RESPONSES"; then
context="$(fetch_post_context "$url")"
if test -n "$NO_PARENT"; then
render_responses "$post" "$context" 0
else
render_post "$post" "$context" 0
fi
else
render_post "$post" "" 0
fi
done
}
# Render a post and/or its responses, taking into account cli arguments.
handle_post_url() {
local url="$1"
local post="$(fetch_post "$url")"
local context="$(fetch_post_context "$url")"
if test -n "$NO_PARENT"; then
render_responses "$post" "$context" 0
else
render_post "$post" "$context" 0
fi
}
usage() {
echo "usage: $(basename "$0") [-h] [-IR] POST_URL"
echo
echo "$(basename "$0") does exactly what it says on the tin: It formats"
echo "a fediverse post (and its replies) into simple-and-embeddable HTML."
echo
echo "It works with posts from any server that supports Mastodons API,"
echo "including Pleroma, Akkoma, Glitch, etc."
echo
echo "Notably, it supports post-atachments and custom-emoji. Keep in mind"
echo "that images are all fetched from remote sources. It is recommended,"
echo "if privacy or total archival, is a concern, to use wget(1)s --mirror"
echo "(or something like it) to fetch even these foreign files."
echo
echo " -c only print the responses (children) of a post"
echo " -h print this message and exit"
echo " -I display posts in reverse-chronological order"
echo " -R do not recursively display posts responses"
}
while getopts 'hcIR' arg; do
case $arg in
h)
usage
exit 0
;;
c)
NO_PARENT="1"
;;
I)
REVERSE_ORDER="1"
;;
R)
NO_RESPONSES="1"
;;
esac
done
shift $((OPTIND-1))
URL="$1"
if test -z "$URL"; then
usage 1>&2
exit 2
fi
USER_ID="$(url_user_id "$URL")"
POST_ID="$(url_post_id "$URL")"
if test -n "$POST_ID"; then
echo "POST"
handle_post_url "$URL"
elif test -n "$USER_ID"; then
handle_user_url "$URL"
else
echo "That URL is not recognized as a post or user URL." 1>&2
exit 3
fi