Parse and compile gettext po and mo files with node.js, nothing more, nothing less.
Please note: starting with version 3 only latest LTS and latest stable node versions are supported. Use version 2 with older node versions.
Include the library:
import gettextParser from "gettext-parser";
Parse a PO file with
gettextParser.po.parse(input[, options]) → Object
Where
- input is a po file as a Buffer or an unicode string. Charset is converted to unicode from other encodings only if the input is a Buffer, otherwise the charset information is discarded
- options is an optional object with the following optional properties:
-
defaultCharset is the charset to use if charset is not defined or is the default
"CHARSET"(applies only if input is a Buffer) -
validation is a flag to turn on PO source file validation. The validation makes sure that:
- there is exactly zero or one
msgid_pluraldefinition per translation entry; aMultiple msgid_plural errorerror gets thrown otherwise. - there are no duplicate entries with exact
msgidvalues; aDuplicate msgid errorerror gets thrown otherwise. - the number of plural forms matches exactly the number from
npluralsdefined inPlural-Formsheader for entries that have plural forms; aPlural forms range errorerror gets thrown otherwise. - the number of
msgstrmatches exacty the one (ifmsgid_pluralis not defined) or the number fromnplurals(ifmsgid_pluralis defined); aTranslation string range errorerror gets thrown otherwise.
- there is exactly zero or one
-
Method returns gettext-parser specific translation object (see below)
Example
import { readFileSync } from 'node:fs';
var input = readFileSync('en.po');
var po = gettextParser.po.parse(input);
console.log(po.translations['']); // output translations for the default contextPO files can also be parsed from a stream source. After all input is processed the parser emits a single 'data' event which contains the parsed translation object.
gettextParser.po.createParseStream([options][, transformOptions]) → Transform Stream
Where
- options is an optional object, same as in
parse. See Parse PO files section for details. - transformOptions are the standard stream options.
Example
import { createReadStream } from 'node:fs';
var input = createReadStream('en.po');
var po = gettextParser.po.createParseStream();
input.pipe(po);
po.on('data', function(data){
console.log(data.translations['']); // output translations for the default context
});If you have a translation object you can convert this to a valid PO file with
gettextParser.po.compile(data[, options]) → Buffer
Where
- data is a translation object either got from parsing a PO/MO file or composed by other means
- options is a configuration object with possible values
- foldLength is the length at which to fold message strings into newlines (default: 76). Set to 0 or false to disable folding.
- sort (boolean|Function) - (default
false) iftrue, entries will be sorted by msgid in the resulting .po(.pot) file. If a comparator function is provided, that function will be used to sort entries in the output. The function is called with two arguments, each of which is a single message entry with the structure described below. The function should follow the standard rules for functions passed toArray.sort(): return0if the entries are interchangeable in sort order; return a number less than 0 if the first entry should come before the second one; and return a number greater than 0 if the second entry should come before the first one. - escapeCharacters (boolean) - (default
true) iffalse, will skip escape newlines and quotes characters functionality.
Example
import { writeFileSync } from 'node:fs';
var data = {
...
};
var output = gettextParser.po.compile(data);
writeFileSync('filename.po', output);Parse a MO file with
gettextParser.mo.parse(input[, defaultCharset]) → Object
Where
- input is a mo file as a Buffer
- defaultCharset is the charset to use if charset is not defined or is the default
"CHARSET"
Method returns gettext-parser specific translation object (see below)
Example
import { readFileSync } from 'node:fs';
var input = readFileSync('en.mo');
var mo = gettextParser.mo.parse(input);
console.log(mo.translations['']); // output translations for the default contextIf you have a translation object you can convert this to a valid MO file with
gettextParser.mo.compile(data) → Buffer
Where
- data is a translation object either got from parsing a PO/MO file or composed by other means
Example
import { writeFileSync } from 'node:fs';
var data = {
...
};
var output = gettextParser.mo.compile(data);
writeFileSync('filename.mo', output);If you are compiling a previously parsed translation object, you can override the output charset with the charset property (applies both for compiling mo and po files).
var obj = gettextParser.po.parse(inputBuf);
obj.charset = "windows-1257";
outputBuf = gettextParser.po.compile(obj);Headers for the output are modified to match the updated charset.
By default gettext-parser uses pure JS iconv-lite for encoding and decoding non UTF-8 charsets. If you need to support more complex encodings that are not supported by iconv-lite, you need to add iconv as an additional dependency for your project (gettext-parser will detect if it is available and tries to use it instead of iconv-lite).
Parsed data is always in unicode but the original charset of the file can
be found from the charset property. This value is also used when compiling translations
to a mo or po file.
Headers can be found from the headers object, all keys are lowercase and the value for a key is a string. This value will also be used when compiling.
Translations can be found from the translations object which in turn holds context objects for msgctxt. Default context can be found from translations[""].
Context objects include all the translations, where msgid value is the key. The value is an object with the following possible properties:
- msgctxt context for this translation, if not present the default context applies
- msgid string to be translated
- msgid_plural the plural form of the original string (might not be present)
- msgstr an array of translations
- comments an object with the following properties:
translator,reference,extracted,flag,previous.
Example
{
"charset": "iso-8859-1",
"headers": {
"content-type": "text/plain; charset=iso-8859-1",
"plural-forms": "nplurals=2; plural=(n!=1);"
},
"translations": {
"": {
"": {
"msgid": "",
"msgstr": ["Content-Type: text/plain; charset=iso-8859-1\n..."]
}
},
"another context": {
"%s example": {
"msgctxt": "another context",
"msgid": "%s example",
"msgid_plural": "%s examples",
"msgstr": ["% näide", "%s näidet"],
"comments": {
"translator": "This is regular comment",
"reference": "/path/to/file:123"
}
}
}
}
}Notice that the structure has both a headers object and a "" translation with the header string. When compiling the structure to a mo or a po file, the headers object is used to define the header. Header string in the "" translation is just for reference (includes the original unmodified data) but will not be used when compiling. So if you need to add or alter header values, use only the headers object.
If you need to convert gettext-parser formatted translation object to something else, eg. for jed, check out po2json.
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