Template parser for ngx-translate

Installation

Just yarn install ngx-translate-parser-plural-select and use when adding ngx-translate to the imports section in your @NgModule:

@NgModule({
    ...
    imports: [
    	...
        TranslateModule.forRoot({
            parser: {
            	provide: TranslateParser,
            	useClass: TranslateICUParser
            }
        })
    ]
})

Usage

Now you can use plural and select in your translations.

{
    "HERO": "The hero is {gender, select, m {male} f {female}}",
    "WOLVES": "The hero saw {wolves, plural, =0 {no wolf} =1 {a wolf} =2 {two wolves} other {a pack of wolves}}",
    "CROWS": "You could see {crows.length, plural, =1 {a crow} few {a few crows} many {a murder of crows}}"
}

And even more complex usages:

{
    "COMPLEX": "{count, plural, =0 { nadie } =1 {{gender, select, m {un hombre} f {una mujer}}} other {{{heroes.length}} {gender, select, m {hombres} f {mujeres}}}}"
}

Notes

Plural supports (first rule matching the value will be applied):

• =value — matches exact value (e.g. =0, =1)
• zero, one, two... — matches values ending in 0, 1, 2, ... that are not between 10 and 19 (inclusive)
• few — matches 2, 3, and 4
• many — matches any value greater than 4 and any non-integer value
• other — matches any value

Custom pipes [v1.1+]

If you want to define your own pipes to use as {variable, *pipe_name*, *pipe_options*}, you can use a factory to create the TranslateICUCustomParser, the class taking a parameter consisting of a dictionary of custom pipes.

Example

@NgModule({
    ...
    imports: [
    	...
        TranslateModule.forRoot({
            parser: {
            	provide: TranslateParser,
            	useFactory: createParserFactory
            }
        })
    ]
})
...

const CUSTOM_PIPES = {
    '?': (value: any, parameters: string[], options: string[]) => {
        parameters = parameters.map(option => option.trim()).slice(0, parameters.length - 1);
        const mapper: {[option: string]: string} = parameters.reduce((map, parameter, index) => ({...map, [parameter.trim()]: options[index]}), {});
        console.dir({value, parameters, options, mapper}, {depth: 10});
        return mapper[value] == null ? mapper[''] : mapper[':'];
    }
};

export function createParserFactory() {
	return new TranslateICUCustomParser(CUSTOM_PIPES);
}

This allows you to use the ? pipe:

Hello, {name, ?, {{name}} : {stranger}}!

Pipe function parameters

The parameters given to the pipe function are:

• the value of the variable the pipe is being applied on
• an array of the strings between the options
• an array of the options,

where the application of the pipe is on a string of the format {value, pipe_name, parameter0 {option0} parameter1 {option1} ... parameterN {optionN} parameterN+1}

Concretely:

During the parsing of the string 'Hello, {name, myPipe, J {Johnny} K {Kenny} L {Lenny} M {Maurice}}', the pipe defined in the dictionary passed to the TranslateICUParser class constructor under the myPipe key will be called with parameters:

1. the value of the name property of the object passed to the ngx-translate function/directive
2. [' J ', ' K ', ' L ', ' M ', '']
3. ['Johnny', 'Kenny', 'Lenny', 'Maurice']