// the functions in this file require the supplementary library lib.js

onload=function()
{
  var txt=document.getElementById("AAL")
  txt.innerHTML = "<div id='askalib-links'><div id='aal-link'><a href='http://www.cod.edu/library/research/askalib.htm' title='Get help by phone, e-mail, chat, or text message' target='_new'>Ask A Librarian</a></div><div id='chat-launch'><a target='_blank' href='http://www.cod.edu/library/global/includes/chatwindow.html' onclick='link_popup(this);return false'>Launch chat</a></div></div>";
  }


// These defaults should be changed the way it best fits your site
var _POPUP_FEATURES = 'location=0,statusbar=0,menubar=0,width=300,height=300';

function raw_popup(url, target, features) {
    // pops up a window containing url optionally named target, optionally having features
    if (isUndefined(features)) features = _POPUP_FEATURES;
    if (isUndefined(target  )) target   = '_blank';
    var leftPos = screen.width - 500;
	var  topPos = window.pageYOffset+ 109;
    var theWindow = window.open(url, target, features + ',top='+topPos+',left='+leftPos);
    theWindow.focus();
    return theWindow;
}

function link_popup(src, features) {
    // to be used in an html event handler as in: <a href="..." onclick="link_popup(this,...)" ...
    // pops up a window grabbing the url from the event source's href
    return raw_popup(src.getAttribute('href'), src.getAttribute('target') || '_blank', features);
}

function event_popup(e) {
    // to be passed as an event listener
    // pops up a window grabbing the url from the event source's href
    link_popup(e.currentTarget);
    e.preventDefault();
}

function event_popup_features(features) {
    // generates an event listener similar to event_popup, but allowing window features
    return function(e) { link_popup(e.currentTarget, features); e.preventDefault() }
}


// DOM

function getElem(elem) {
    if (document.getElementById) {
        if (typeof elem == "string") {
            elem = document.getElementById(elem);
            if (elem===null) throw 'cannot get element: element does not exist';
        } else if (typeof elem != "object") {
            throw 'cannot get element: invalid datatype';
        }
    } else throw 'cannot get element: unsupported DOM';
    return elem;
}

function hasClass(elem, className) {
    return getElem(elem).className.split(' ').has(className);
}

function getElementsByClass(className, tagName, parentNode) {
    parentNode = !isUndefined(parentNode)? getElem(parentNode) : document;
    if (isUndefined(tagName)) tagName = '*';
    return filter(parentNode.getElementsByTagName(tagName),
        function(elem) { return hasClass(elem, className) });
}


// DOM EVENTS

function listen(event, elem, func) {
    elem = getElem(elem);
    if (elem.addEventListener)  // W3C DOM
        elem.addEventListener(event,func,false);
    else if (elem.attachEvent)  // IE DOM
        elem.attachEvent('on'+event, function(){ func(new W3CDOM_Event(elem)) } );
        // for IE we use a wrapper function that passes in a simplified faux Event object.
    else throw 'cannot add event listener';
}

function mlisten(event, elem_list, func) {
    map(elem_list, function(elem) { listen(event, elem, func) } );
}

function W3CDOM_Event(currentTarget) {
    this.currentTarget  = currentTarget;
    this.preventDefault = function() { window.event.returnValue = false }
    return this;
}


// MISC CLEANING-AFTER-MICROSOFT STUFF

function isUndefined(v) {
    var undef;
    return v===undef;
}

