Export i18n from template and ts file for angular 9

Readme.MD

To extract message, run following command:

yarn extract-i18n

angular.json

{
  "projects": {
    "my-app": {
      "architech": {
        ...
        ...
         "xliffmerge": {
          "builder": "@ngx-i18nsupport/tooling:xliffmerge",
          "options": {
            "xliffmergeOptions": {
              "i18nFormat": "xlf",
              "srcDir": "src/i18n",
              "genDir": "src/i18n",
              "defaultLanguage": "en",
              "languages": [
                "en",
                "fr"
                "ru"
                "vi"
              ]
            }
          }
        },
        ...
      }
    }
  }
}

index.js

// path: tools/xlf-merge/index.js

#!/usr/bin/env node

const program = require('commander');
const fs = require('fs');
const convert = require('xml-js');
const shell = require('shelljs');
const mergeXlf = require('./merge-xlf');

function runMerge(inputPaths, outputPath) {
    const inputFiles = (function*() { yield* shell.ls(inputPaths); })();
    const sourceFile = inputFiles.next().value;
    
    console.log('Initial file', sourceFile);
    let fileContent = fs.readFileSync(sourceFile).toString();
    let output = convert.xml2js(fileContent);
    
    for (let fileIter = inputFiles.next(); !fileIter.done; fileIter = inputFiles.next()) {
        fileContent = fs.readFileSync(fileIter.value).toString();
        output = mergeXlf(output, convert.xml2js(fileContent), fileIter.value);
    }
    
    const outXml = convert.js2xml(output);
    fs.writeFileSync(outputPath, outXml);
    console.log('Generated output file', outputPath);
}

//runMerge(['data/test3/generic.xlf', 'data/test3/home-page.xlf', 'data/test3/lesson.xlf'], 'data/test3/out.xlf');
//return;

program
    .version('1.0.3')
    .usage('[options] <input files or pattern such as *.xlf ...>')
    .option('-o, --output <output>', 'Output file name')
    .parse(process.argv);

if (program.args === 0 || !program.output) {
    program.help();
}

try {
    runMerge(program.args, program.output);
}
catch (err) {
    console.error(err);
}

install.sh

# Angular 9 come with new Ivy engine, xi18n tool do not support for new engine so we can't extract translate messages.
# This script tool support extract i18n from templates and ts file

# Install require package
yarn add shx @locl/cli xml-js @ngx-i18nsupport/ngx-i18nsupport @ngx-i18nsupport/tooling 

merge-xlf.js

// path: tools/xlf-merge/merge-xlf.js
module.exports = function(first, second, fileName) {
    function fail(message) {
        throw new Error(message + ' File name: ' + fileName + '.');
    }

    function getElement(src, path, isOptional) {
        let result = src;
        let breadcrumbs = '';
    
        for (const pnode of path) {
            breadcrumbs += '/' + pnode;
    
            if (!result.elements) {
                if (!isOptional) {
                    fail(breadcrumbs + ' - expected element ' + pnode + ' not found. Make sure that the XLF file schema is correct.');
                } else {
                    return null;
                }
            }
    
            result = result.elements.find(e => e.name === pnode);
            if (!result) {
                if (!isOptional) {
                    fail('Element ' + breadcrumbs + ' not found. Make sure that the XLF file schema is correct.');
                } else {
                    return null;
                }
            }
        }
    
        return result;
    }
    
    function getContent(src) {
        const result = ((src && src.elements) || []).find(e => e.type === 'text');
        return result ? result.text : '';
    }
    
    function* getTransUnits(root) {
        if (!root.elements) {
            console.log('Skipping ', fileName, '- no trans-units found.');
            return;
        }
    
        for (const el of root.elements) {
            if (el.name === 'trans-unit') {
                yield el;
            }
        }
    }

    const transPath = ['xliff', 'file', 'body'];
    const srcRoot = getElement(first, transPath);
    const tgtRoot = getElement(second, transPath);
    const tgtTransUnits = [...getTransUnits(tgtRoot)];
    let numMergedTransUnits = 0;

    function findTgtById(id) {
        return tgtTransUnits.find(t => t.attributes && t.attributes.id === id);
    }

    for (const srcTransUnit of getTransUnits(srcRoot)) {
        const id = srcTransUnit.attributes.id;
        const content = getContent(getElement(srcTransUnit, ['target'], true));

        const matchingTgt = findTgtById(id);
        if (matchingTgt) {
            const tgtContent = getContent(getElement(matchingTgt, ['target'], true));
            if (content !== tgtContent) {
                console.log(`"${content}"`, ' <- ', id, ' -> ', `"${tgtContent}"`);
            }
        } else {
            tgtRoot.elements.push(srcTransUnit);
            numMergedTransUnits++;
        }
    }

    console.log(fileName, ' -> ', numMergedTransUnits, 'translations merged');
    return second;
}

package.json

// Add following scripts to package.json file
// Asume
{
  "merge-i18n": "node ./tools/xlf-merge/ src/i18n/tool/*.en.xlf -o src/i18n/messages.xlf",
  "gen-i18n": "yarn shx rm -rf src/i18n/tool && yarn locl extract -s=dist/web/*.js -f=xlf -o=src/i18n/tool/ && yarn merge-i18n",
  "extract-i18n": "ng build --prod && yarn gen-i18n && ng run my-app:xliffmerge && yarn shx rm -rf src/i18n/tool",
}