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Diffstat (limited to 'src/util/strings.js')
| -rw-r--r-- | src/util/strings.js | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/util/strings.js b/src/util/strings.js new file mode 100644 index 0000000..cf4d88c --- /dev/null +++ b/src/util/strings.js @@ -0,0 +1,207 @@ +import { logWarn } from './cli.js'; + +// Localiz8tion time! Or l10n as the neeeeeeeerds call it. Which is a terri8le +// name and not one I intend on using, thank you very much. (Don't even get me +// started on """"a11y"""".) +// +// All the default strings are in strings-default.json, if you're curious what +// those actually look like. Pretty much it's "I like {ANIMAL}" for example. +// For each language, the o8ject gets turned into a single function of form +// f(key, {args}). It searches for a key in the o8ject and uses the string it +// finds (or the one in strings-default.json) as a templ8 evaluated with the +// arguments passed. (This function gets treated as an o8ject too; it gets +// the language code attached.) +// +// The function's also responsi8le for getting rid of dangerous characters +// (quotes and angle tags), though only within the templ8te (not the args), +// and it converts the keys of the arguments o8ject from camelCase to +// CONSTANT_CASE too. +// +// This function also takes an optional "bindUtilities" argument; it should +// look like a dictionary each value of which is itself a util dictionary, +// each value of which is a function in the format (value, opts) => (...). +// Each of those util dictionaries will 8e attached to the final returned +// strings() function, containing functions which automatically have that +// same strings() function provided as part of its opts argument (alongside +// any additional arguments passed). +// +// Basically, it's so that instead of doing: +// +// count.tracks(album.tracks.length, {strings}) +// +// ...you can just do: +// +// strings.count.tracks(album.tracks.length) +// +// Definitely note bindUtilities expects an OBJECT, not an array, otherwise +// it won't 8e a8le to know what keys to attach the utilities 8y! +// +// Oh also it'll need access to the he.encode() function, and callers have to +// provide that themselves, 'cuz otherwise we can't reference this file from +// client-side code. +export function genStrings(stringsJSON, { + he, + defaultJSON = null, + bindUtilities = [] +}) { + // genStrings will only 8e called once for each language, and it happens + // right at the start of the program (or at least 8efore 8uilding pages). + // So, now's a good time to valid8te the strings and let any warnings be + // known. + + // May8e contrary to the argument name, the arguments should 8e o8jects, + // not actual JSON-formatted strings! + if (typeof stringsJSON !== 'object' || stringsJSON.constructor !== Object) { + return {error: `Expected an object (parsed JSON) for stringsJSON.`}; + } + if (typeof defaultJSON !== 'object') { // typeof null === object. I h8 JS. + return {error: `Expected an object (parsed JSON) or null for defaultJSON.`}; + } + + // All languages require a language code. + const code = stringsJSON['meta.languageCode']; + if (!code) { + return {error: `Missing language code.`}; + } + if (typeof code !== 'string') { + return {error: `Expected language code to be a string.`}; + } + + // Every value on the provided o8ject should be a string. + // (This is lazy, but we only 8other checking this on stringsJSON, on the + // assumption that defaultJSON was passed through this function too, and so + // has already been valid8ted.) + { + let err = false; + for (const [ key, value ] of Object.entries(stringsJSON)) { + if (typeof value !== 'string') { + logError`(${code}) The value for ${key} should be a string.`; + err = true; + } + } + if (err) { + return {error: `Expected all values to be a string.`}; + } + } + + // Checking is generally done against the default JSON, so we'll skip out + // if that isn't provided (which should only 8e the case when it itself is + // 8eing processed as the first loaded language). + if (defaultJSON) { + // Warn for keys that are missing or unexpected. + const expectedKeys = Object.keys(defaultJSON); + const presentKeys = Object.keys(stringsJSON); + for (const key of presentKeys) { + if (!expectedKeys.includes(key)) { + logWarn`(${code}) Unexpected translation key: ${key} - this won't be used!`; + } + } + for (const key of expectedKeys) { + if (!presentKeys.includes(key)) { + logWarn`(${code}) Missing translation key: ${key} - this won't be localized!`; + } + } + } + + // Valid8tion is complete, 8ut We can still do a little caching to make + // repeated actions faster. + + // We're gonna 8e mut8ting the strings dictionary o8ject from here on out. + // We make a copy so we don't mess with the one which was given to us. + stringsJSON = Object.assign({}, stringsJSON); + + // Preemptively pass everything through HTML encoding. This will prevent + // strings from embedding HTML tags or accidentally including characters + // that throw HTML parsers off. + for (const key of Object.keys(stringsJSON)) { + stringsJSON[key] = he.encode(stringsJSON[key], {useNamedReferences: true}); + } + + // It's time to cre8te the actual langauge function! + + // In the function, we don't actually distinguish 8etween the primary and + // default (fall8ack) strings - any relevant warnings have already 8een + // presented a8ove, at the time the language JSON is processed. Now we'll + // only 8e using them for indexing strings to use as templ8tes, and we can + // com8ine them for that. + const stringIndex = Object.assign({}, defaultJSON, stringsJSON); + + // We do still need the list of valid keys though. That's 8ased upon the + // default strings. (Or stringsJSON, 8ut only if the defaults aren't + // provided - which indic8tes that the single o8ject provided *is* the + // default.) + const validKeys = Object.keys(defaultJSON || stringsJSON); + + const invalidKeysFound = []; + + const strings = (key, args = {}) => { + // Ok, with the warning out of the way, it's time to get to work. + // First make sure we're even accessing a valid key. (If not, return + // an error string as su8stitute.) + if (!validKeys.includes(key)) { + // We only want to warn a8out a given key once. More than that is + // just redundant! + if (!invalidKeysFound.includes(key)) { + invalidKeysFound.push(key); + logError`(${code}) Accessing invalid key ${key}. Fix a typo or provide this in strings-default.json!`; + } + return `MISSING: ${key}`; + } + + const template = stringIndex[key]; + + // Convert the keys on the args dict from camelCase to CONSTANT_CASE. + // (This isn't an OUTRAGEOUSLY versatile algorithm for doing that, 8ut + // like, who cares, dude?) Also, this is an array, 8ecause it's handy + // for the iterating we're a8out to do. + const processedArgs = Object.entries(args) + .map(([ k, v ]) => [k.replace(/[A-Z]/g, '_$&').toUpperCase(), v]); + + // Replacement time! Woot. Reduce comes in handy here! + const output = processedArgs.reduce( + (x, [ k, v ]) => x.replaceAll(`{${k}}`, v), + template); + + // Post-processing: if any expected arguments *weren't* replaced, that + // is almost definitely an error. + if (output.match(/\{[A-Z_]+\}/)) { + logError`(${code}) Args in ${key} were missing - output: ${output}`; + } + + return output; + }; + + // And lastly, we add some utility stuff to the strings function. + + // Store the language code, for convenience of access. + strings.code = code; + + // Store the strings dictionary itself, also for convenience. + strings.json = stringsJSON; + + // Store Intl o8jects that can 8e reused for value formatting. + strings.intl = { + date: new Intl.DateTimeFormat(code, {full: true}), + number: new Intl.NumberFormat(code), + list: { + conjunction: new Intl.ListFormat(code, {type: 'conjunction'}), + disjunction: new Intl.ListFormat(code, {type: 'disjunction'}), + unit: new Intl.ListFormat(code, {type: 'unit'}) + }, + plural: { + cardinal: new Intl.PluralRules(code, {type: 'cardinal'}), + ordinal: new Intl.PluralRules(code, {type: 'ordinal'}) + } + }; + + const bindOpts = (obj, bind) => Object.fromEntries(Object.entries(obj).map( + ([ key, fn ]) => [key, (value, opts = {}) => fn(value, {...bind, ...opts})] + )); + + // And the provided utility dictionaries themselves, of course! + for (const [key, utilDict] of Object.entries(bindUtilities)) { + strings[key] = bindOpts(utilDict, {strings}); + } + + return strings; +} |