I add 10 functions to a code, I don't even cal

问题:

Alone, this code works:

CustomButton = {

1: function () {
  alert("Just testing") 
  },

}

I add the code below and the code above stops working:

function getvisitingnow() {
    return document.location;
}
function getcontents(uri) {
    var req = new XMLHttpRequest();
    req.open('GET', uri, true);
    req.onreadystatechange = function (aEvt) {
        if (req.readyState == 4) {
            if(req.status == 200) {
                return req.responseText;
            }
        }
    };
    req.send();
}
function regexforsitefound(uri, searchcontents) {
    var re = new RegExp("\\<div class=g\\>.*?(?:\\<a href=\\\"?(.*?)\\\"?\\>.*?){2}\\</div\\>", "mi");
    var sitefound = searchcontents.match(re);
    if (sitefound[0]) return sitefound[0] else return null;
}
function regexforcategoryfound(uri, searchcontents) {
    var re = new RegExp("\\<div class=g\\>.*?(?:\\<a href=\\\"?(.*?)\\\"?\\>.*?){2}\\</div\\>", "mi");
    var categoryfound = searchcontents.match(re);
    if (categoryfound[1]) return categoryfound[1] else return null;
}
function regexfordomainname(uri) {
    var re = new RegExp("http://(?:[A-Za-z0-9-]+\\.)?[A-Za-z0-9-]+\\.[A-Za-z0-9-]+/?", "si");
    var domainname = uri.match(re);
    if (domainname) return domainname;
}
function regexforparentdir(uri) {
    var re = new RegExp("http://(?:[A-Za-z0-9-]+\\.)?[A-Za-z0-9-]+\\.[A-Za-z0-9-]+/?", "si");
    var parentdir = uri.match(re);
    if (parentdir) return parentdir;
}
function getcomparisonlink(visitingnow) {
    var searchuri = null;
    var searchcontents = null;
    var uri = visitingnow;
    while(true) {
        searchuri = 'http://www.google.com.br/search?';
        searchuri += 'q='+ uri +'&btnG=Search+Directory&hl=en&cat=gwd%2FTop';
        searchcontents = getcontents(searchuri);
        var sitefound = regexforsitefound(searchcontents);
        if (sitefound) {
            var categoryfound = regexforcategoryfound(searchcontents);
            if (categoryfound) {
                return categoryfound;
            }
        } else {
            var domainname = regexfordomainname(uri);
            if (!domainname) {
                var parentdir = regexforparentdir(uri);
                uri = parentdir;
            } else {
                return null;
            }
        }
    }
}
function clickedlink(event){
    var visitingnow = getvisitingnow(); 
    if (visitingnow) {
        getcomparisonlink(visitingnow);
        if (comparisonlink) {
            tab.open(comparisonlink);
        };
    }
}
function createBookmarkItem() {
    const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
    var item = document.createElementNS(XUL_NS, "toolbarbutton");
    item.setAttribute("id", "Testing-Doit-Button2");
    item.setAttribute("class", "bookmark-item pagerank");
    item.setAttribute("tooltiptext", "Do it!");
    item.setAttribute("oncommand", "testing_doit();");
    return item;
}
function placeBookmarkItem() {
    var toolbar = document.getElementById("PersonalToolbar");
    var button = createBookmarkItem();
    toolbar.appendChild(button);
}

Why?

回答1:

if (sitefound[0]) return sitefound[0] else return null;

This syntax is invalid.

Try:

if (sitefound[0])
    return sitefound[0];
else 
    return null;

回答2:

try adding your functions one by one. see at which function your code stops working. then empty the function contents only to put it back with pieces at a time. check again where your code stops working. about there should be a syntax error.

But as Bobby suggests, the easier way is to try Firefox Errorlog, or maybe Firebug.

回答3:

One little JavaScript-error can break a lot of things. You have forgotten to add semicolons in two places.

There needs to be a semicolon after sitefound[0] here:

function regexforsitefound(uri, searchcontents) {
    var re = new RegExp("\\<div class=g\\>.*?(?:\\<a href=\\\"?(.*?)\\\"?\\>.*?    ){2}\\</div\\>", "mi");
    var sitefound = searchcontents.match(re);
    if (sitefound[0]) return sitefound[0] else return null; 
}

and one after categoryfound[1] here:

function regexforcategoryfound(uri, searchcontents) {
    var re = new RegExp("\\<div class=g\\>.*?(?:\\<a href=\\\"?(.*?)\\\"?\\>.*?){2}\\</div\\>", "mi");
    var categoryfound = searchcontents.match(re);
    if (categoryfound[1]) return categoryfound[1] else return null;
}

回答4:

If you are a Mac user, open (a recent version) of Safari and hit

⌥⌘ + i,

which opens up a great panel with lots of charts and data about the client-server interaction. You can also see and locate javascript errors, or debug javascript in a console directly. neat.

For Firefox, try the excellent firebug to see, what went wrong where .. in their own words: [with Firebug] .. you can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

回答5:

The comma after the function in CustomButton can break code the code in IE. Also, if you are using CustomButton the first time here, you should introduce it with var. I know these are not the issues you asked for, but otherwise, everything seems correct.