trilium/src/public/app/widgets/dialogs/options/spellcheck.js

import utils from "../../../services/utils.js";
import server from "../../../services/server.js";
import toastService from "../../../services/toast.js";

const TPL = `
<style>
.disabled-field {
    opacity: 0.5;
    pointer-events: none;
}
</style>

<div>
    <h4>Spell check</h4>

    <p>These options apply only for desktop builds, browsers will use their own native spell check. App restart is required after change.</p>

    <div class="custom-control custom-checkbox">
        <input type="checkbox" class="custom-control-input" id="spell-check-enabled">
        <label class="custom-control-label" for="spell-check-enabled">Enable spellcheck</label>
    </div>

    <br/>

    <div class="form-group">
        <label for="spell-check-language-code">Language code(s)</label>
        <input type="text" class="form-control" id="spell-check-language-code" placeholder="for example &quot;en-US&quot;, &quot;de-AT&quot;">
    </div>

    <p>Multiple languages can be separated by comma, e.g. <code>en-US, de-DE, cs</code>. Changes to the spell check options will take effect after application restart.</p>
    
    <p><strong>Available language codes: </strong> <span id="available-language-codes"></span></p>
</div>`;

export default class SpellcheckOptions {
    constructor() {
        $("#options-spellcheck").html(TPL);

        this.$spellCheckEnabled = $("#spell-check-enabled");
        this.$spellCheckLanguageCode = $("#spell-check-language-code");

        this.$spellCheckEnabled.on('change', () => {
            const opts = { 'spellCheckEnabled': this.$spellCheckEnabled.is(":checked") ? "true" : "false" };
            server.put('options', opts).then(() => toastService.showMessage("Options change have been saved."));

            return false;
        });

        this.$spellCheckLanguageCode.on('change', () => {
            const opts = { 'spellCheckLanguageCode': this.$spellCheckLanguageCode.val() };
            server.put('options', opts).then(() => toastService.showMessage("Options change have been saved."));

            return false;
        });

        this.$availableLanguageCodes = $("#available-language-codes");

        if (utils.isElectron()) {
            const { webContents } = utils.dynamicRequire('@electron/remote').getCurrentWindow();

            this.$availableLanguageCodes.text(webContents.session.availableSpellCheckerLanguages.join(', '));
        }
    }

    optionsLoaded(options) {
        this.$spellCheckEnabled.prop("checked", options['spellCheckEnabled'] === 'true');
        this.$spellCheckLanguageCode.val(options['spellCheckLanguageCode']);
    }
}