How to load a table, from another webpage, into an array?

问题

I am creating a Greasemonkey/Tampermonkey script that puts some stats into an array.

Using JavaScript, how would I make it so a page loads a URL (football.fantasysports.yahoo.com/f1/326198/pointsagainst?pos=QB) in the background and creates an array with the first two columns (Rank and Team)?

The problem I am having is doing all of this in the background, I presume I would be using AJAX. Any help would be appreciated.

回答1:

For a static page (like the one you linked), use GM_xmlhttpRequest() and DOMParser to extract the elements you want. See below.

For a dynamic page^{(AJAX driven)}, use the techniques from How to get an AJAX get-request to wait for the page to be rendered before returning a response?

Here's a complete script showing how to extract info from a third party page and make it into an array variable:

// ==UserScript==
// @name        _Grab stuff of a *static*, third-party web site.
// @include     https://stackoverflow.com/questions/*
// @require     http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js
// @grant       GM_xmlhttpRequest
// ==/UserScript==

GM_xmlhttpRequest ( {
    method:     "GET",
    url:        "http://football.fantasysports.yahoo.com/f1/326198/pointsagainst?pos=QB&ntid=",
    onload:     parseResponse,
    onerror:    function (e) { console.error ('**** error ', e); },
    onabort:    function (e) { console.error ('**** abort ', e); },
    ontimeout:  function (e) { console.error ('**** timeout ', e); }
} );

function parseResponse (response) {
    var parser  = new DOMParser ();
    /* IMPORTANT!
        1) For older browsers, see
        https://developer.mozilla.org/en-US/docs/Web/API/DOMParser
        for a work-around.

        2) jQuery.parseHTML() and similar is bad because it causes images, etc., to be loaded.
    */
    var ajaxDoc         = parser.parseFromString (response.responseText, "text/html");
    var statRows        = ajaxDoc.querySelectorAll ("#statTable0 > tbody > tr");
    var newStatTable    = $(statRows).map ( function () {
        var tblRow      = $(this);
        var teamRank    = parseInt (tblRow.find (".rank-indicator").text().trim(), 10);
        var teamName    = tblRow.find ("td:eq(1)").text().trim();

        return [ [teamRank, teamName] ];
    } ).get ();

    /*-- newStatTable, is a 2-D array like:
        [   [1, "Team A"],
            [2, "Team B"],
            [3, "Team C"],
            //etc...
        ]
    */
    console.log (newStatTable);
    //alert (newStatTable);
}

回答2:

I think you want to do something like:

// ==UserScript==

// @name          Fantasy Stuff

// @namespace     http://football.fantasysports.yahoo.com/f1/326198/pointsagainst?pos=QB&ntid=

// @description   An example of Fantasy Stuff

// @include       *

// ==/UserScript==

var doc = document;
function T(t){
  return doc.getElementsByTagName(t);
}
var tms = T('tbody')[0].getElementsByTagName('a'), teams = [];
for(var i=0,n=1,l=tms.length; i<l; i++,n++){
  teams[n] = tms[i].text;
}
// teams array should hold results
console.log(teams); // in FireFox

来源：https://stackoverflow.com/questions/32321979/how-to-load-a-table-from-another-webpage-into-an-array

标签

javascript

arrays

greasemonkey

tampermonkey