@ngx-translate/core
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text/typescript
import {Injectable} from "@angular/core";
import {isDefined} from "./util";
export abstract class TranslateParser {
/**
* Interpolates a string to replace parameters
* "This is a {{ key }}" ==> "This is a value", with params = { key: "value" }
* @param expr
* @param params
*/
abstract interpolate(expr: string | Function, params?: any): string | undefined;
/**
* Gets a value from an object by composed key
* parser.getValue({ key1: { keyA: 'valueI' }}, 'key1.keyA') ==> 'valueI'
* @param target
* @param key
*/
abstract getValue(target: any, key: string): any
}
()
export class TranslateDefaultParser extends TranslateParser {
templateMatcher: RegExp = /{{\s?([^{}\s]*)\s?}}/g;
public interpolate(expr: string | Function, params?: any): string {
let result: string;
if (typeof expr === 'string') {
result = this.interpolateString(expr, params);
} else if (typeof expr === 'function') {
result = this.interpolateFunction(expr, params);
} else {
// this should not happen, but an unrelated TranslateService test depends on it
result = expr as string;
}
return result;
}
getValue(target: any, key: string): any {
let keys = typeof key === 'string' ? key.split('.') : [key];
key = '';
do {
key += keys.shift();
if (isDefined(target) && isDefined(target[key]) && (typeof target[key] === 'object' || !keys.length)) {
target = target[key];
key = '';
} else if (!keys.length) {
target = undefined;
} else {
key += '.';
}
} while (keys.length);
return target;
}
private interpolateFunction(fn: Function, params?: any) {
return fn(params);
}
private interpolateString(expr: string, params?: any) {
if (!params) {
return expr;
}
return expr.replace(this.templateMatcher, (substring: string, b: string) => {
let r = this.getValue(params, b);
return isDefined(r) ? r : substring;
});
}
}