Function for extracting the asker, question, and question details from Yahoo Answer question pages.

getYahooQuestion.js

/** Pass an object with `asker`, `question`, and `details` properties for the given Yahoo Answers
 * question page URL to the callback function.
*/
(function getYahooQuestion(url, callback) {

    /** Error to throw when a user data ID cannot be found. */
    class NoUserDataIdError extends Error {
        constructor() {
            super();
            this.name = 'NoUserDataIdError';
        }
    }

    /** Resolve promise if response is OK, otherwise, reject with an error. */
    const checkStatus = function checkResponseStatus(res) {
        return res.ok ?
            Promise.resolve(res) :
            Promise.reject(new Error(`${res.url} returned ${res.status} (${res.statusText})`));
    };

    /** Convenience function for creating a DOM from HTML text. */
    const makeDOM = function makeDomFromHTMLString(htmlString) {
        const domTree = document.createElement('html');
        domTree.innerHTML = htmlString;
        return domTree;
    };

    /** Resolve promise if a data ID of the question asker exists in the provided DOM, otherwise
     * reject with a NoUserDataIdError.
    */
    const getUserDataId = function getUserDataIdFromDOM(dom) {
        if (dom.querySelector('#yq-question-detail-profile-img .profileImage') !== null) {
            const askerDataId = dom
                .querySelector('#yq-question-detail-profile-img .profileImage')
                .getAttribute('data-id');
            return Promise.resolve(askerDataId);
        }

        return Promise.reject(new NoUserDataIdError('Unable to find asker data ID'));
    };

    /** Return a URL query string from a given object. */
    const buildQueryString = function buildQueryStringFromObject(params) {
        // Shorten this function name for convenience
        const enc = encodeURIComponent;
        return Object.keys(params)
            .map(key => `${enc(key)}=${enc(params[key])}`)
            .join('&')
    }

    /** Return a fetch promise for the URL containing profile information for the given user
     * data ID.
    */
    const fetchProfileCard = function fetchProfileCard(dataId) {
        const requestParams = {name: 'YAProfileCardModule', show: dataId};
        const requestUrl = `https://answers.yahoo.com/_module?${buildQueryString(requestParams)}`;
        return fetch(requestUrl);
    };

    /** Return the user name from the profile information returned by `fetchProfileCard()`. */
    const getNameFromProfileCard = function getNameFromProfileCard(profileCardJson) {
        return makeDOM(profileCardJson.YAProfileCardModule.html)
            .querySelector('#profile-nickname').textContent;
    };

    /** Resolve promise with the question title from the DOM of a Yahoo Answers question page. */
    const getQuestionFromDom = function getQuestionFromDom(dom) {
        return Promise.resolve(dom.querySelector('#ya-question-detail h1').textContent.trim());
    };

    /** Resolve promise with the question details from the DOM of a Yahoo Answers question page.
     *
     * If no question details found, reject promise with Error.
    */
    const getQuestionDetailsFromDom = function getQuestionDetailsFromDom(dom) {
        if (dom.querySelector('#ya-question-detail .ya-q-show-more') !== null) {
            return Promise.resolve(
                dom.querySelector('#ya-question-detail .ya-q-full-text').textContent.trim()
            );
        }

        if (dom.querySelector('#ya-question-detail .ya-q-text') !== null) {
            return Promise.resolve(
                dom.querySelector('#ya-question-detail .ya-q-text').textContent.trim()
            );
        }

        return Promise.reject(new Error('No question details found'));
    };

    /** Return the question asker name from the DOM of a Yahoo Answers question page.
     *
     * If the user is anonymous, return "Anonymous".
     *
     * If the user no longer exists, return "<Error: User not found>"
    */
    const getAskerNameFromDom = function getAskerNameFromDom(dom) {
        return getUserDataId(dom)
            .then(fetchProfileCard)
            .then(checkStatus)
            .then(response => response.json())
            .then(getNameFromProfileCard)
            .catch(error => (
                error.name === 'NoUserDataIdError' ?
                    'Anonymous' :
                    '<Error: User not found>'
            ));
    };

    // Don't even try to run this function on a non-Yahoo Answers page
    const yahooRegex = /^https:\/\/answers\.yahoo\.com\/question\/index\?qid=\w+/g;
    if (!yahooRegex.test(url)) {
        throw new Error('This script only accepts Yahoo Answer URLs');
    }

    // Fetch the page HTML and extract the information
    fetch(url)
        .then(checkStatus)
        .then(response => response.text())
        .then(makeDOM)
        .then(pageDom => (
            Promise.all([
                getAskerNameFromDom(pageDom),
                getQuestionFromDom(pageDom),
                getQuestionDetailsFromDom(pageDom).catch(''),
            ])
        ))
        .then((promises) => {
            const [asker, question, details] = promises;
            return {asker, question, details}
        })
        .then(callback);
}(window.location.href, console.log));

Sample URLs:

• Known User: https://answers.yahoo.com/question/index?qid=20080921134525AAiNaF0
• Anonymous User: https://answers.yahoo.com/question/index?qid=20170408122251AAqeUbg
• Deleted User: https://answers.yahoo.com/question/index?qid=20071201141309AA5iRQv