DuckDuckGoogle

Try to search DuckDuckGo, and if it fails, use Google instead.

Tính đến 31-08-2018. Xem phiên bản mới nhất.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(Tôi đã có Trình quản lý tập lệnh người dùng, hãy cài đặt nó!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name DuckDuckGoogle
// @description Try to search DuckDuckGo, and if it fails, use Google instead.
// @author ForgottenUmbrella
// @namespace https://greasyfork.org/users/83187
// @version 1.0.1
// @match https://duckduckgo.com
// ==/UserScript==

// Some schools' proxy servers interfere with DDG's privacy measures, so
// students have to resort to Google. This userscript seeks to automate
// that process.
// It is recommended that users don't sign in to Google, or use a
// container to protect their privacy.

// Return a URL for searching Google.
function googleSearchUrl(query) {
    const base = "https://www.google.com";
    return `${base}/search?q=${query}`;
}

// Return the search query on DuckDuckGo.
function ddgQuery(searchUrl) {
    const params = new URLSearchParams(searchUrl);
    return params.get("q");
}

// Return whether Firefox has encountered a HTTP error.
function firefoxError() {
    const errors = document.getElementsByClassName("error-message");
    return errors.length !== 0;
}

// Navigate to a URL.
function goto(url) {
    location.href = url;
}

(() => {
    // TODO: Handle Chrome failures.
    const failed = firefoxError();
    if (failed) {
        goto(googleSearchUrl(ddgQuery(location.href)));
    }
})();