trilium/src/public/javascripts/services/server.js

import protectedSessionHolder from './protected_session_holder.js';
import utils from './utils.js';
import infoService from "./info.js";

function getHeaders() {
    let protectedSessionId = null;

    try { // this is because protected session might not be declared in some cases - like when it's included in migration page
        protectedSessionId = protectedSessionHolder.getProtectedSessionId();
    }
    catch(e) {}

    // headers need to be lowercase because node.js automatically converts them to lower case
    // so hypothetical protectedSessionId becomes protectedsessionid on the backend
    return {
        protected_session_id: protectedSessionId,
        source_id: glob.sourceId
    };
}

async function get(url) {
    return await call('GET', url);
}

async function post(url, data) {
    return await call('POST', url, data);
}

async function put(url, data) {
    return await call('PUT', url, data);
}

async function remove(url) {
    return await call('DELETE', url);
}

let i = 1;
const reqResolves = {};

async function call(method, url, data) {
    if (utils.isElectron()) {
        const ipc = require('electron').ipcRenderer;
        const requestId = i++;

        return new Promise((resolve, reject) => {
            reqResolves[requestId] = resolve;

            console.log(utils.now(), "Request #" + requestId + " to " + method + " " + url);

            ipc.send('server-request', {
                requestId: requestId,
                headers: getHeaders(),
                method: method,
                url: "/" + baseApiUrl + url,
                data: data
            });
        });
    }
    else {
        return await ajax(url, method, data);
    }
}

async function ajax(url, method, data) {
    const options = {
        url: baseApiUrl + url,
        type: method,
        headers: getHeaders()
    };

    if (data) {
        try {
            options.data = JSON.stringify(data);
        }
        catch (e) {
            console.log("Can't stringify data: ", data, " because of error: ", e)
        }
        options.contentType = "application/json";
    }

    return await $.ajax(options).catch(e => {
        const message = "Error when calling " + method + " " + url + ": " + e.status + " - " + e.statusText;
        infoService.showError(message);
        infoService.throwError(message);
    });
}

setTimeout(() => {
    if (utils.isElectron()) {
        const ipc = require('electron').ipcRenderer;

        ipc.on('server-response', (event, arg) => {
            console.log(utils.now(), "Response #" + arg.requestId + ": " + arg.statusCode);

            reqResolves[arg.requestId](arg.body);

            delete reqResolves[arg.requestId];
        });
    }
}, 100);

export default {
    get,
    post,
    put,
    remove,
    ajax,
    // don't remove, used from CKEditor image upload!
    getHeaders
};