From 297921fce570bfab413bab4e16a4ae694ecc4f28 Mon Sep 17 00:00:00 2001 From: kibigo! Date: Wed, 12 Jul 2017 01:02:51 -0700 Subject: Moved glitch files to their own location ;) --- app/javascript/glitch/util/bio_metadata.js | 380 +++++++++++++++++++++++++++++ 1 file changed, 380 insertions(+) create mode 100644 app/javascript/glitch/util/bio_metadata.js (limited to 'app/javascript/glitch/util') diff --git a/app/javascript/glitch/util/bio_metadata.js b/app/javascript/glitch/util/bio_metadata.js new file mode 100644 index 000000000..bdbb1750b --- /dev/null +++ b/app/javascript/glitch/util/bio_metadata.js @@ -0,0 +1,380 @@ +/*********************************************************************\ + + To my lovely code maintainers, + + The syntax recognized by the Mastodon frontend for its bio metadata + feature is a subset of that provided by the YAML 1.2 specification. + In particular, Mastodon recognizes metadata which is provided as an + implicit YAML map, where each key-value pair takes up only a single + line (no multi-line values are permitted). To simplify the level of + processing required, Mastodon metadata frontmatter has been limited + to only allow those characters in the `c-printable` set, as defined + by the YAML 1.2 specification, instead of permitting those from the + `nb-json` characters inside double-quoted strings like YAML proper. + ¶ It is important to note that Mastodon only borrows the *syntax* + of YAML, not its semantics. This is to say, Mastodon won't make any + attempt to interpret the data it receives. `true` will not become a + boolean; `56` will not be interpreted as a number. Rather, each key + and every value will be read as a string, and as a string they will + remain. The order of the pairs is unchanged, and any duplicate keys + are preserved. However, YAML escape sequences will be replaced with + the proper interpretations according to the YAML 1.2 specification. + ¶ The implementation provided below interprets `
` as `\n` and + allows for an open

tag at the beginning of the bio. It replaces + the escaped character entities `'` and `"` with single or + double quotes, respectively, prior to processing. However, no other + escaped characters are replaced, not even those which might have an + impact on the syntax otherwise. These minor allowances are provided + because the Mastodon backend will insert these things automatically + into a bio before sending it through the API, so it is important we + account for them. Aside from this, the YAML frontmatter must be the + very first thing in the bio, leading with three consecutive hyphen- + minues (`---`), and ending with the same or, alternatively, instead + with three periods (`...`). No limits have been set with respect to + the number of characters permitted in the frontmatter, although one + should note that only limited space is provided for them in the UI. + ¶ The regular expression used to check the existence of, and then + process, the YAML frontmatter has been split into a number of small + components in the code below, in the vain hope that it will be much + easier to read and to maintain. I leave it to the future readers of + this code to determine the extent of my successes in this endeavor. + + Sending love + warmth eternal, + - kibigo [@kibi@glitch.social] + +\*********************************************************************/ + +/* CONVENIENCE FUNCTIONS */ + +const unirex = str => new RegExp(str, 'u'); +const rexstr = exp => '(?:' + exp.source + ')'; + +/* CHARACTER CLASSES */ + +const DOCUMENT_START = /^/; +const DOCUMENT_END = /$/; +const ALLOWED_CHAR = // `c-printable` in the YAML 1.2 spec. + /[\t\n\r\x20-\x7e\x85\xa0-\ud7ff\ue000-\ufffd\u{10000}-\u{10FFFF}]/u; +const WHITE_SPACE = /[ \t]/; +const INDENTATION = / */; // Indentation must be only spaces. +const LINE_BREAK = /\r?\n|\r|/; +const ESCAPE_CHAR = /[0abt\tnvfre "\/\\N_LP]/; +const HEXADECIMAL_CHARS = /[0-9a-fA-F]/; +const INDICATOR = /[-?:,[\]{}&#*!|>'"%@`]/; +const FLOW_CHAR = /[,[\]{}]/; + +/* NEGATED CHARACTER CLASSES */ + +const NOT_WHITE_SPACE = unirex('(?!' + rexstr(WHITE_SPACE) + ')[^]'); +const NOT_LINE_BREAK = unirex('(?!' + rexstr(LINE_BREAK) + ')[^]'); +const NOT_INDICATOR = unirex('(?!' + rexstr(INDICATOR) + ')[^]'); +const NOT_FLOW_CHAR = unirex('(?!' + rexstr(FLOW_CHAR) + ')[^]'); +const NOT_ALLOWED_CHAR = unirex( + '(?!' + rexstr(ALLOWED_CHAR) + ')[^]' +); + +/* BASIC CONSTRUCTS */ + +const ANY_WHITE_SPACE = unirex(rexstr(WHITE_SPACE) + '*'); +const ANY_ALLOWED_CHARS = unirex(rexstr(ALLOWED_CHAR) + '*'); +const NEW_LINE = unirex( + rexstr(ANY_WHITE_SPACE) + rexstr(LINE_BREAK) +); +const SOME_NEW_LINES = unirex( + '(?:' + rexstr(ANY_WHITE_SPACE) + rexstr(LINE_BREAK) + ')+' +); +const POSSIBLE_STARTS = unirex( + rexstr(DOCUMENT_START) + rexstr(/]*>/) + '?' +); +const POSSIBLE_ENDS = unirex( + rexstr(SOME_NEW_LINES) + '|' + + rexstr(DOCUMENT_END) + '|' + + rexstr(/<\/p>/) +); +const CHARACTER_ESCAPE = unirex( + rexstr(/\\/) + + '(?:' + + rexstr(ESCAPE_CHAR) + '|' + + rexstr(/x/) + rexstr(HEXADECIMAL_CHARS) + '{2}' + '|' + + rexstr(/u/) + rexstr(HEXADECIMAL_CHARS) + '{4}' + '|' + + rexstr(/U/) + rexstr(HEXADECIMAL_CHARS) + '{8}' + + ')' +); +const ESCAPED_CHAR = unirex( + rexstr(/(?!["\\])/) + rexstr(NOT_LINE_BREAK) + '|' + + rexstr(CHARACTER_ESCAPE) +); +const ANY_ESCAPED_CHARS = unirex( + rexstr(ESCAPED_CHAR) + '*' +); +const ESCAPED_APOS = unirex( + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + rexstr(/[^']|''/) +); +const ANY_ESCAPED_APOS = unirex( + rexstr(ESCAPED_APOS) + '*' +); +const FIRST_KEY_CHAR = unirex( + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + + rexstr(NOT_INDICATOR) + '|' + + rexstr(/[?:-]/) + + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + + '(?=' + rexstr(NOT_FLOW_CHAR) + ')' +); +const FIRST_VALUE_CHAR = unirex( + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + + rexstr(NOT_INDICATOR) + '|' + + rexstr(/[?:-]/) + + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + // Flow indicators are allowed in values. +); +const LATER_KEY_CHAR = unirex( + rexstr(WHITE_SPACE) + '|' + + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + + '(?=' + rexstr(NOT_FLOW_CHAR) + ')' + + rexstr(/[^:#]#?/) + '|' + + rexstr(/:/) + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' +); +const LATER_VALUE_CHAR = unirex( + rexstr(WHITE_SPACE) + '|' + + '(?=' + rexstr(NOT_LINE_BREAK) + ')' + + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' + + // Flow indicators are allowed in values. + rexstr(/[^:#]#?/) + '|' + + rexstr(/:/) + '(?=' + rexstr(NOT_WHITE_SPACE) + ')' +); + +/* YAML CONSTRUCTS */ + +const YAML_START = unirex( + rexstr(ANY_WHITE_SPACE) + rexstr(/---/) +); +const YAML_END = unirex( + rexstr(ANY_WHITE_SPACE) + rexstr(/(?:---|\.\.\.)/) +); +const YAML_LOOKAHEAD = unirex( + '(?=' + + rexstr(YAML_START) + + rexstr(ANY_ALLOWED_CHARS) + rexstr(NEW_LINE) + + rexstr(YAML_END) + rexstr(POSSIBLE_ENDS) + + ')' +); +const YAML_DOUBLE_QUOTE = unirex( + rexstr(/"/) + rexstr(ANY_ESCAPED_CHARS) + rexstr(/"/) +); +const YAML_SINGLE_QUOTE = unirex( + rexstr(/'/) + rexstr(ANY_ESCAPED_APOS) + rexstr(/'/) +); +const YAML_SIMPLE_KEY = unirex( + rexstr(FIRST_KEY_CHAR) + rexstr(LATER_KEY_CHAR) + '*' +); +const YAML_SIMPLE_VALUE = unirex( + rexstr(FIRST_VALUE_CHAR) + rexstr(LATER_VALUE_CHAR) + '*' +); +const YAML_KEY = unirex( + rexstr(YAML_DOUBLE_QUOTE) + '|' + + rexstr(YAML_SINGLE_QUOTE) + '|' + + rexstr(YAML_SIMPLE_KEY) +); +const YAML_VALUE = unirex( + rexstr(YAML_DOUBLE_QUOTE) + '|' + + rexstr(YAML_SINGLE_QUOTE) + '|' + + rexstr(YAML_SIMPLE_VALUE) +); +const YAML_SEPARATOR = unirex( + rexstr(ANY_WHITE_SPACE) + + ':' + rexstr(WHITE_SPACE) + + rexstr(ANY_WHITE_SPACE) +); +const YAML_LINE = unirex( + '(' + rexstr(YAML_KEY) + ')' + + rexstr(YAML_SEPARATOR) + + '(' + rexstr(YAML_VALUE) + ')' +); + +/* FRONTMATTER REGEX */ + +const YAML_FRONTMATTER = unirex( + rexstr(POSSIBLE_STARTS) + + rexstr(YAML_LOOKAHEAD) + + rexstr(YAML_START) + rexstr(SOME_NEW_LINES) + + '(?:' + + '(' + rexstr(INDENTATION) + ')' + + rexstr(YAML_LINE) + rexstr(SOME_NEW_LINES) + + '(?:' + + '\\1' + rexstr(YAML_LINE) + rexstr(SOME_NEW_LINES) + + '){0,4}' + + ')?' + + rexstr(YAML_END) + rexstr(POSSIBLE_ENDS) +); + +/* SEARCHES */ + +const FIND_YAML_LINES = unirex( + rexstr(NEW_LINE) + rexstr(INDENTATION) + rexstr(YAML_LINE) +); + +/* STRING PROCESSING */ + +function processString(str) { + switch (str.charAt(0)) { + case '"': + return str + .substring(1, str.length - 1) + .replace(/\\0/g, '\x00') + .replace(/\\a/g, '\x07') + .replace(/\\b/g, '\x08') + .replace(/\\t/g, '\x09') + .replace(/\\\x09/g, '\x09') + .replace(/\\n/g, '\x0a') + .replace(/\\v/g, '\x0b') + .replace(/\\f/g, '\x0c') + .replace(/\\r/g, '\x0d') + .replace(/\\e/g, '\x1b') + .replace(/\\ /g, '\x20') + .replace(/\\"/g, '\x22') + .replace(/\\\//g, '\x2f') + .replace(/\\\\/g, '\x5c') + .replace(/\\N/g, '\x85') + .replace(/\\_/g, '\xa0') + .replace(/\\L/g, '\u2028') + .replace(/\\P/g, '\u2029') + .replace( + new RegExp( + unirex( + rexstr(/\\x/) + '(' + rexstr(HEXADECIMAL_CHARS) + '{2})' + ), 'gu' + ), (_, n) => String.fromCodePoint('0x' + n) + ) + .replace( + new RegExp( + unirex( + rexstr(/\\u/) + '(' + rexstr(HEXADECIMAL_CHARS) + '{4})' + ), 'gu' + ), (_, n) => String.fromCodePoint('0x' + n) + ) + .replace( + new RegExp( + unirex( + rexstr(/\\U/) + '(' + rexstr(HEXADECIMAL_CHARS) + '{8})' + ), 'gu' + ), (_, n) => String.fromCodePoint('0x' + n) + ); + case '\'': + return str + .substring(1, str.length - 1) + .replace(/''/g, '\''); + default: + return str; + } +} + +/* BIO PROCESSING */ + +export function processBio(content) { + content = content.replace(/"/g, '"').replace(/'/g, '\''); + let result = { + text: content, + metadata: [], + }; + let yaml = content.match(YAML_FRONTMATTER); + if (!yaml) return result; + else yaml = yaml[0]; + let start = content.search(YAML_START); + let end = start + yaml.length - yaml.search(YAML_START); + result.text = content.substr(0, start) + content.substr(end); + let metadata = null; + let query = new RegExp(FIND_YAML_LINES, 'g'); + while ((metadata = query.exec(yaml))) { + result.metadata.push([ + processString(metadata[1]), + processString(metadata[2]), + ]); + } + return result; +} + +/* BIO CREATION */ + +export function createBio(note, data) { + if (!note) note = ''; + let frontmatter = ''; + if ((data && data.length) || note.match(/^\s*---\s+/)) { + if (!data) frontmatter = '---\n...\n'; + else { + frontmatter += '---\n'; + for (let i = 0; i < data.length; i++) { + let key = '' + data[i][0]; + let val = '' + data[i][1]; + + // Key processing + if (key === (key.match(YAML_SIMPLE_KEY) || [])[0]) /* do nothing */; + else if (key.indexOf('\'') === -1 && key === (key.match(ANY_ESCAPED_APOS) || [])[0]) key = '\'' + key + '\''; + else { + key = key + .replace(/\x00/g, '\\0') + .replace(/\x07/g, '\\a') + .replace(/\x08/g, '\\b') + .replace(/\x0a/g, '\\n') + .replace(/\x0b/g, '\\v') + .replace(/\x0c/g, '\\f') + .replace(/\x0d/g, '\\r') + .replace(/\x1b/g, '\\e') + .replace(/\x22/g, '\\"') + .replace(/\x5c/g, '\\\\'); + let badchars = key.match( + new RegExp(rexstr(NOT_ALLOWED_CHAR), 'gu') + ) || []; + for (let j = 0; j < badchars.length; j++) { + key = key.replace( + badchars[i], + '\\u' + badchars[i].codePointAt(0).toLocaleString('en', { + useGrouping: false, + minimumIntegerDigits: 4, + }) + ); + } + key = '"' + key + '"'; + } + + // Value processing + if (val === (val.match(YAML_SIMPLE_VALUE) || [])[0]) /* do nothing */; + else if (val.indexOf('\'') === -1 && val === (val.match(ANY_ESCAPED_APOS) || [])[0]) val = '\'' + val + '\''; + else { + val = val + .replace(/\x00/g, '\\0') + .replace(/\x07/g, '\\a') + .replace(/\x08/g, '\\b') + .replace(/\x0a/g, '\\n') + .replace(/\x0b/g, '\\v') + .replace(/\x0c/g, '\\f') + .replace(/\x0d/g, '\\r') + .replace(/\x1b/g, '\\e') + .replace(/\x22/g, '\\"') + .replace(/\x5c/g, '\\\\'); + let badchars = val.match( + new RegExp(rexstr(NOT_ALLOWED_CHAR), 'gu') + ) || []; + for (let j = 0; j < badchars.length; j++) { + val = val.replace( + badchars[i], + '\\u' + badchars[i].codePointAt(0).toLocaleString('en', { + useGrouping: false, + minimumIntegerDigits: 4, + }) + ); + } + val = '"' + val + '"'; + } + + frontmatter += key + ': ' + val + '\n'; + } + frontmatter += '...\n'; + } + } + return frontmatter + note; +} -- cgit