c8fdb2541c9758c0db06e4cf7fff3e4a0160d54b
tdreszer
Fri May 2 16:48:41 2014 -0700
Took this one step further: moved methods to their own cart object and now append queued cart updates to any hgTracks ajax update. This will provide greater flexibilty for future cart update queuing. Redmone #13164.
diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index 1174e25..151344b 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -259,31 +259,31 @@
pos.chromStart+1, pos.chromEnd);
return newPosition;
},
handleChange: function (response, status)
{
var json = eval("(" + response + ")");
genomePos.set(json.pos);
},
changeAssemblies: function (ele) // UNUSED? Larry's experimental code
{ // code to update page when user changes assembly select list.
$.ajax({
type: "GET",
url: "../cgi-bin/hgApi",
- data: "cmd=defaultPos&db=" + getDb(),
+ data: cart.addUpdatesToUrl("cmd=defaultPos&db=" + getDb()),
dataType: "html",
trueSuccess: genomePos.handleChange,
success: catchErrorOrDispatch,
error: errorHandler,
cache: true
});
return false;
}
}
/////////////////////////////////////
//// Creating items by dragging /////
/////////////////////////////////////
var makeItemsByDrag = {
@@ -441,37 +441,113 @@
if ($(obj).hasClass('noLink')) // TITLE_BUT_NO_LINK
return false;
if (obj.href.match('#') || obj.target.length > 0) {
//alert("Matched # ["+obj.href+"] or has target:"+obj.target);
return true;
}
var thisForm=$(obj).parents('form');
if(thisForm == undefined || $(thisForm).length == 0)
thisForm=$("FORM");
if($(thisForm).length > 1 )
thisForm=$(thisForm)[0];
if(thisForm != undefined && $(thisForm).length == 1) {
//alert("posting form:"+$(thisForm).attr('name'));
- var href = vis.cartUpdatesAddToUrl(obj.href);
+ var href = cart.addUpdatesToUrl(obj.href);
return postTheForm($(thisForm).attr('name'),href);
}
return true;
}
}
+/////////////////////////
+//// cart updating /////
+///////////////////////
+var cart = {
+
+ updateQueue: {},
+
+ updatesWaiting: function ()
+ { // returns TRUE if updates are waiting.
+ return (Object.keys(cart.updateQueue).length !== 0);
+ },
+
+ addUpdatesToUrl: function (url)
+ { // adds any outstanding cart updates to the url, then clears the queue
+ if (cart.updatesWaiting()) {
+ var updates = "";
+ for (var track in cart.updateQueue) {
+ updates += "&" + track + "=" + cart.updateQueue[track];
+ }
+ if (updates.length > 0) {
+ if(url.length > 0 && url.lastIndexOf("?") == -1 && url.lastIndexOf("&") == -1)
+ url += "?" + updates.substring(1);
+ else
+ url += updates
+ }
+ cart.updateQueue = {};
+ }
+ return url;
+ },
+
+ // NOTE: could update in background, however, failing to hit "refresh" is a user choice
+ // updatesViaAjax: function ()
+ // { // Called via timer: updates the cart via setVars.
+ // if (!cart.updatesWaiting())
+ // return;
+ //
+ // var tracks = [];
+ // var newVis = [];
+ // for (var track in cart.updateQueue) {
+ // tracks.push(track)
+ // newVis.push(cart.updateQueue[track]);
+ // }
+ // if (tracks.length === 0)
+ // return;
+ // cart.updateQueue = {};
+ // setCartVars(tracks,newVis,async=false); // sync to avoid another race condition mess
+ // },
+
+ addUpdateToQueue: function (track,newVis)
+ { // creates a string of updates to save for ajax batch or a submit
+ cart.updateQueue[track] = newVis;
+
+ // NOTE: could update in background, however, failing to hit "refresh" is a user choice
+ // first in queue, schedule background update
+ // if (Object.keys(cart.updateQueue).length === 1)
+ // setTimeout("cart.updatesViaAjax();",10000);
+ },
+
+ setVars: function (names, values, errFunc, async)
+ { // ajax updates the cart, and includes any queued updates.
+ if (cart.updatesWaiting()) {
+ for (var track in cart.updateQueue) {
+ names.push(track);
+ values.push(cart.updateQueue[track]);
+ }
+ cart.updateQueue = {};
+ }
+ setCartVars(names, values, errFunc, async);
+ },
+
+ setVar: function (names, values, errFunc, async)
+ { // wraps single var update to expected arrays
+ vis.setVars( [ name ], [ value ], errFunc, async );
+ }
+}
+
///////////////////////////////////////////////
//// visibility (mixed with group toggle) /////
///////////////////////////////////////////////
var vis = {
enumOrder: new Array("hide", "dense", "full", "pack", "squish"), // map cgi enum visibility codes to strings
cartUpdateQueue: {},
update: function (track, visibility)
{ // Updates visibility state in hgTracks.trackDb and any visible elements on the page.
// returns true if we modify at least one select in the group list
var rec = hgTracks.trackDb[track];
var selectUpdated = false;
$("select[name=" + escapeJQuerySelectorChars(track) + "]").each(function(t) {
$(this).attr('class', visibility == 'hide' ? 'hiddenText' : 'normalText');
@@ -515,97 +591,48 @@
return setTableRowVisibility(button, prefix, "hgtgroup", "group",false,arguments[2]);
else
return setTableRowVisibility(button, prefix, "hgtgroup", "group",false);
},
expandAllGroups: function (newState)
{ // Set visibility of all track groups to newState (true means expanded).
// This code also modifies the corresponding hidden fields and the gif's of the +/- img tag.
imageV2.markAsDirtyPage();
$(".toggleButton[id$='_button']").each( function (i) { // works for old img type AND new BUTTONS_BY_CSS
vis.toggleForGroup(this,this.id.substring(0,this.id.length - 7),newState); // clip '_button' suffix
});
return false;
},
- cartUpdatesWaiting: function ()
- { // returns TRUE if updates are waiting.
- return (Object.keys(vis.cartUpdateQueue).length !== 0);
- },
-
- cartUpdatesAddToUrl: function (url)
- { // adds any outstanding cart updates to the url, then clears the queue
- var updates = "";
- for (var track in vis.cartUpdateQueue) {
- updates += "&" + track + "=" + vis.cartUpdateQueue[track];
- }
- if (updates.length > 0) {
- if(url.length > 0 && url.lastIndexOf("?") == -1 && url.lastIndexOf("&") == -1)
- url += "?" + updates.substring(1);
- else
- url += updates
- }
- vis.cartUpdateQueue = {};
- return url;
- },
-
- // NOTE: could update in background, however, failing to hit "refresh" is a user choice
- // cartUpdatesViaAjax: function ()
- // { // Called via timer: updates the cart via setVars.
- // if (!vis.cartUpdatesWaiting())
- // return;
- //
- // var tracks = [];
- // var newVis = [];
- // for (var track in vis.cartUpdateQueue) {
- // tracks.push(track)
- // newVis.push(vis.cartUpdateQueue[track]);
- // }
- // if (tracks.length === 0)
- // return;
- // vis.cartUpdateQueue = {};
- // setCartVars(tracks,newVis,async=false); // sync to avoid another race condition mess
- // },
-
- cartUpdateAddToQueue: function (track,newVis)
- { // creates a string of updates to save for ajax batch or a submit
- vis.cartUpdateQueue[track] = newVis;
-
- // NOTE: could update in background, however, failing to hit "refresh" is a user choice
- // first in queue, schedule background update
- // if (Object.keys(vis.cartUpdateQueue).length === 1)
- // setTimeout("vis.cartUpdatesViaAjax();",10000);
- },
-
initForAjax: function()
{ // To better support the back-button, it is good to eliminate extraneous form puts
// Towards that end, we support visBoxes making ajax calls to update cart.
var sels = $('select.normalText,select.hiddenText');
$(sels).change(function() {
var track = $(this).attr('name');
if ($(this).val() == 'hide') {
var rec = hgTracks.trackDb[track];
if(rec)
rec.visibility = 0;
// else Would be nice to hide subtracks as well but that may be overkill
$(document.getElementById('tr_' + track)).remove();
imageV2.highlightRegion();
$(this).attr('class', 'hiddenText');
} else
$(this).attr('class', 'normalText');
- vis.cartUpdateAddToQueue(track,$(this).val());
+ cart.addUpdateToQueue(track,$(this).val());
return false;
});
// Now we can rid the submt of the burden of all those vis boxes
var form = $('form#TrackForm');
$(form).submit(function () {
$('select.normalText,select.hiddenText').attr('disabled',true);
});
$(form).attr('method','get');
},
restoreFromBackButton: function()
// Re-enabling vis dropdowns is necessarty because intiForAjax() disables them on submit.
{
$('select.normalText,select.hiddenText').attr('disabled',false);
}
@@ -647,31 +674,31 @@
highlightThisRegion: function(newPosition)
// set highlighting newPosition in server-side cart and apply the highlighting in local UI.
{
var start, end;
if (arguments.length == 2) {
start = arguments[0];
end = arguments[1];
} else {
var pos = parsePosition(newPosition);
start = pos.start;
end = pos.end;
}
hgTracks.highlight = getDb() + "." + hgTracks.chromName + ":" + start + "-" + end;
hgTracks.highlight += '#AAFFFF'; // Also include highlight color
// we include enableHighlightingDialog because it may have been changed by the dialog
- setCartVars(['highlight', 'enableHighlightingDialog'],
+ cart.setVars(['highlight', 'enableHighlightingDialog'],
[hgTracks.highlight, hgTracks.enableHighlightingDialog ? 1 : 0]);
imageV2.highlightRegion();
},
selectionEndDialog: function (newPosition)
// Let user choose between zoom-in and highlighting.
{
var dragSelectDialog = $("#dragSelectDialog")[0];
if (!dragSelectDialog) {
$("body").append("<div id='dragSelectDialog'>" + newPosition +
"<p><input type='checkbox' id='disableDragHighlight'>" +
"Don't show this dialog again and always zoom.<BR>" +
"(Re-enable highlight via the 'configure' menu at any time.)</p>");
dragSelectDialog = $("#dragSelectDialog")[0];
}
@@ -685,31 +712,31 @@
minWidth: 400,
buttons: {
"Zoom In": function() {
// Zoom to selection
$(this).dialog("option", "revertToOriginalPos", false);
if ($("#disableDragHighlight").attr('checked'))
hgTracks.enableHighlightingDialog = false;
if (imageV2.inPlaceUpdate) {
var params = "position=" + newPosition;
if (!hgTracks.enableHighlightingDialog)
params += "&enableHighlightingDialog=0"
imageV2.navigateInPlace(params, null, true);
} else {
$('body').css('cursor', 'wait');
if (!hgTracks.enableHighlightingDialog)
- setCartVars(['enableHighlightingDialog'],[0]);
+ cart.setVars(['enableHighlightingDialog'],[0]);
document.TrackHeaderForm.submit();
}
$(this).dialog("close");
},
"Highlight": function() {
// Highlight selection
$(imageV2.imgTbl).imgAreaSelect({hide:true});
if ($("#disableDragHighlight").attr('checked'))
hgTracks.enableHighlightingDialog = false;
dragSelect.highlightThisRegion(newPosition);
$(this).dialog("close");
},
"Cancel": function() {
$(this).dialog("close");
}
@@ -1141,31 +1168,31 @@
var dragReorder = {
setOrder: function (table)
{ // Sets the 'order' value for the image table after a drag reorder
var names = [];
var values = [];
$("tr.imgOrd").each(function (i) {
if ($(this).attr('abbr') != $(this).attr('rowIndex').toString()) {
$(this).attr('abbr',$(this).attr('rowIndex').toString());
var name = this.id.substring('tr_'.length) + '_imgOrd';
names.push(name);
values.push($(this).attr('abbr'));
}
});
if(names.length > 0) {
- setCartVars(names,values);
+ cart.setVars(names,values);
imageV2.markAsDirtyPage();
}
},
sort: function (table)
{ // Sets the table row order to match the order of the abbr attribute.
// This is needed for back-button, and for visBox changes combined with refresh.
var tbody = $(table).find('tbody')[0];
if(tbody == undefined)
tbody = table;
// Do we need to sort?
var trs = tbody.rows;
var needToSort = false;
$(trs).each(function(ix) {
@@ -1990,31 +2017,31 @@
}
}
if(imageV2.inPlaceUpdate) {
// XXXX This attempt to "update whole track image in place" didn't work for a variety of reasons
// (e.g. safari doesn't parse map when we update on the client side), so this is currently dead code.
// However, this now works in all other browsers, so we may turn this on for non-safari browsers
// (see redmine #4667).
jQuery('body').css('cursor', '');
var data = "hgt.trackImgOnly=1&hgt.ideogramToo=1&position=" +
newPosition + "&hgsid=" + getHgsid();
if(name)
data += "&hgFind.matches=" + name;
$.ajax({
type: "GET",
url: "../cgi-bin/hgTracks",
- data: data,
+ data: cart.addUpdatesToUrl(data),
dataType: "html",
trueSuccess: imageV2.updateImgAndMap,
success: catchErrorOrDispatch,
error: errorHandler,
cmd: cmd,
loadingId: showLoadingImage("imgTbl"),
cache: false
});
} else {
// do a full page refresh to update hgTracks image
jQuery('body').css('cursor', 'wait');
var ele;
if(document.TrackForm)
ele = document.TrackForm;
else
@@ -2027,32 +2054,32 @@
}
}
} else if (cmd == 'zoomCodon' || cmd == 'zoomExon') {
var num, ajaxCmd, msg;
if(cmd == 'zoomCodon') {
msg = "Please enter the codon number to jump to:";
ajaxCmd = 'codonToPos';
} else {
msg = "Please enter the exon number to jump to:";
ajaxCmd = 'exonToPos';
}
rightClick.myPrompt(msg, function(results) {
$.ajax({
type: "GET",
url: "../cgi-bin/hgApi",
- data: "db=" + getDb() + "&cmd=" + ajaxCmd + "&num=" + results +
- "&table=" + args.table + "&name=" + args.name,
+ data: cart.addUpdatesToUrl("db=" + getDb() + "&cmd=" + ajaxCmd + "&num=" +
+ results + "&table=" + args.table + "&name=" + args.name),
trueSuccess: rightClick.handleZoomCodon,
success: catchErrorOrDispatch,
error: errorHandler,
cache: true
});
});
} else if (cmd == 'hgTrackUi_popup') {
popUp.hgTrackUi( rightClick.selectedMenuItem.id, false ); // Launches the popup but shields the ajax with a waitOnFunction
} else if (cmd == 'hgTrackUi_follow') {
var url = "hgTrackUi?hgsid=" + getHgsid() + "&g=";
var rec = hgTracks.trackDb[id];
if (tdbHasParent(rec) && tdbIsLeaf(rec))
@@ -2068,31 +2095,31 @@
} else if (cmd == 'viewImg') {
// Fetch a new copy of track img and show it to the user in another window. This code assume we have updated
// remote cart with all relevant chages (e.g. drag-reorder).
/* Here's how to do this more directly with hgRenderTracks:
if(window.open("../cgi-bin/hgRenderTracks?hgt.internal=1&hgsid=" + getHgsid()) == null) {
rightClick.windowOpenFailedMsg();
}
return;
*/
var data = "hgt.imageV1=1&hgt.trackImgOnly=1&hgsid=" + getHgsid();
jQuery('body').css('cursor', 'wait');
$.ajax({
type: "GET",
url: "../cgi-bin/hgTracks",
- data: data,
+ data: cart.addUpdatesToUrl(data),
dataType: "html",
trueSuccess: rightClick.handleViewImg,
success: catchErrorOrDispatch,
error: errorHandler,
cmd: cmd,
cache: false
});
} else if (cmd == 'openLink' || cmd == 'followLink') {
var href = rightClick.selectedMenuItem.href;
var vars = new Array("c", "l", "r", "db");
var valNames = new Array("chromName", "winStart", "winEnd");
for (var i in vars) {
// make sure the link contains chrom and window width info (necessary b/c we are stripping hgsid and/or the cart may be empty);
// but don't add chrom to wikiTrack links (see redmine #2476).
var v = vars[i];
@@ -2138,92 +2165,92 @@
var row = $( 'tr#tr_' + id );
var rows = dragReorder.getContiguousRowSet(row);
if (rows && rows.length > 0) {
var vars = new Array();
var vals = new Array();
for (var ix=rows.length - 1; ix >= 0; ix--) { // from bottom, just in case remove screws with us
var rowId = $(rows[ix]).attr('id').substring('tr_'.length);
//if (tdbIsSubtrack(hgTracks.trackDb[rowId]) == false)
// warn('What went wrong?');
vars.push(rowId, rowId+'_sel'); // Remove subtrack level vis and explicitly uncheck.
vals.push('[]', 0);
$(rows[ix]).remove();
}
if (vars.length > 0) {
- setCartVars( vars, vals );
+ cart.setVars( vars, vals );
}
imageV2.afterImgChange(true);
}
} else if (cmd == 'hideComposite') {
var rec = hgTracks.trackDb[id];
if (tdbIsSubtrack(rec)) {
var row = $( 'tr#tr_' + id );
var rows = dragReorder.getCompositeSet(row);
if (rows && rows.length > 0) {
for (var ix=rows.length - 1; ix >= 0; ix--) { // from bottom, just in case remove screws with us
$(rows[ix]).remove();
}
var selectUpdated = vis.update(rec.parentTrack, 'hide');
- setCartVar(rec.parentTrack, 'hide' );
+ cart.setVar(rec.parentTrack, 'hide' );
imageV2.afterImgChange(true);
}
}
} else if (cmd == 'jumpToHighlight') { // If highlight exists for this assembly, jump to it
if (hgTracks.highlight) {
var newPos = parsePositionWithDb(hgTracks.highlight);
if (newPos && newPos.db == getDb()) {
if ( $('#highlightItem').length == 0) { // not visible? jump to it
var curPos = parsePosition(genomePos.get());
var diff = ((curPos.end - curPos.start) - (newPos.end - newPos.start));
if (diff > 0) { // new position is smaller then current, then center it
newPos.start = Math.max( Math.floor(newPos.start - (diff/2) ), 0 );
newPos.end = newPos.start + (curPos.end - curPos.start);
}
}
if (imageV2.inPlaceUpdate) {
var params = "position=" + newPos.chrom+':'+newPos.start+'-'+newPos.end;
imageV2.navigateInPlace(params, null, true);
} else {
genomePos.setByCoordinates(newPos.chrom, newPos.start, newPos.end);
jQuery('body').css('cursor', 'wait');
document.TrackHeaderForm.submit();
}
}
}
} else if (cmd == 'removeHighlight') {
hgTracks.highlight = null;
- setCartVars(['highlight'], ['[]']);
+ cart.setVars(['highlight'], ['[]']);
imageV2.highlightRegion();
} else { // if ( cmd in 'hide','dense','squish','pack','full','show' )
// Change visibility settings:
//
// First change the select on our form:
var rec = hgTracks.trackDb[id];
var selectUpdated = vis.update(id, cmd);
// Now change the track image
if(imageV2.enabled && cmd == 'hide')
{
// Hide local display of this track and update server side cart.
// Subtracks controlled by 2 settings so del vis and set sel=0. Others, just set vis hide.
if(tdbIsSubtrack(rec))
- setCartVars( [ id, id+"_sel" ], [ '[]', 0 ] ); // Remove subtrack level vis and explicitly uncheck.
+ cart.setVars( [ id, id+"_sel" ], [ '[]', 0 ] ); // Remove subtrack level vis and explicitly uncheck.
else if(tdbIsFolderContent(rec))
- setCartVars( [ id, id+"_sel" ], [ 'hide', 0 ] ); // supertrack children need to have _sel set to trigger superttrack reshaping
+ cart.setVars( [ id, id+"_sel" ], [ 'hide', 0 ] ); // supertrack children need to have _sel set to trigger superttrack reshaping
else
- setCartVar(id, 'hide' );
+ cart.setVar(id, 'hide' );
$(document.getElementById('tr_' + id)).remove();
imageV2.afterImgChange(true);
} else if (!imageV2.mapIsUpdateable) {
jQuery('body').css('cursor', 'wait');
if(selectUpdated) {
// assert(document.TrackForm);
document.TrackForm.submit();
} else {
// add a hidden with new visibility value
var form = $(document.TrackHeaderForm);
$("<input type='hidden' name='"+id+"'value='"+cmd+"'>").appendTo(form);
document.TrackHeaderForm.submit();
}
} else {
imageV2.requestImgUpdate(id, id + "=" + cmd, "", cmd);
@@ -2614,31 +2641,31 @@
myLink += "&descriptionOnly=1";
var rec = hgTracks.trackDb[trackName];
if (!descriptionOnly && rec != null && rec["configureBy"] != null) {
if (rec["configureBy"] == 'none')
return;
else if (rec["configureBy"] == 'clickThrough') {
jQuery('body').css('cursor', 'wait');
window.location = myLink;
return;
} // default falls through to configureBy popup
}
myLink += "&ajax=1";
$.ajax({
type: "GET",
- url: myLink,
+ url: cart.addUpdatesToUrl(myLink),
dataType: "html",
trueSuccess: popUp.uiDialog,
success: catchErrorOrDispatch,
error: errorHandler,
cmd: rightClick.selectedMenuItem,
cache: false
});
},
hgTrackUi: function (trackName,descriptionOnly)
{
waitOnFunction( popUp._uiDialigRequest, trackName, descriptionOnly ); // Launches the popup but shields the ajax with a waitOnFunction
},
uiDialogOk: function (popObj, trackName)
@@ -3008,31 +3035,31 @@
requestImgUpdate: function (trackName,extraData,loadingId,newVisibility)
{
// extraData, loadingId and newVisibility are optional
var data = "hgt.trackImgOnly=1&hgsid=" + getHgsid() + "&hgt.trackNameFilter=" + trackName;
if(extraData != undefined && extraData != "")
data += "&" + extraData;
if(loadingId == undefined || loadingId == "")
loadingId = showLoadingImage("tr_" + trackName);
var getOrPost = "GET";
if ((data.length) > 2000) // extraData could contain a bunch of changes from the cfg dialog
getOrPost = "POST";
$.ajax({
type: getOrPost,
url: "../cgi-bin/hgTracks",
- data: data,
+ data: cart.addUpdatesToUrl(data),
dataType: "html",
trueSuccess: imageV2.updateImgAndMap,
success: catchErrorOrDispatch,
error: errorHandler,
cmd: 'refresh',
loadingId: loadingId,
id: trackName,
newVisibility: newVisibility,
cache: false
});
},
fullReload: function()
{
// force reload of whole page via trackform submit
@@ -3255,31 +3282,31 @@
if(keepCurrentTrackVisible) {
var item = rightClick.currentMapItem || imageV2.lastTrack;
if(item) {
var top = $(document.getElementById("tr_" + item.id)).position().top;
if(top >= $(window).scrollTop()
|| top < $(window).scrollTop() + $(window).height()) {
// don't bother if the item is not currently visible.
currentId = item.id;
currentIdYOffset = top - $(window).scrollTop();
}
}
}
$.ajax({
type: "GET",
url: "../cgi-bin/hgTracks",
- data: vis.cartUpdatesAddToUrl(params +
+ data: cart.addUpdatesToUrl(params +
"&hgt.trackImgOnly=1&hgt.ideogramToo=1&hgsid=" +
getHgsid()),
dataType: "html",
trueSuccess: imageV2.updateImgAndMap,
success: catchErrorOrDispatch,
error: errorHandler,
cmd: 'wholeImage',
loadingId: showLoadingImage("imgTbl"),
disabledEle: disabledEle,
currentId: currentId,
currentIdYOffset: currentIdYOffset,
cache: false
});
},
@@ -3372,33 +3399,33 @@
// TODO: move elsewhere?
// With history support it is best that most position changes will ajax-update the image
// This ensures that the 'go' and 'refresh' button will do so unless the chrom changes.
$("input[value='go'],input[value='refresh']").click(function () {
var newPos = genomePos.get().replace(/,/g,'');
var newChrom = newPos.split(':')[0];
var oldChrom = genomePos.getOriginalPos().split(':')[0];
if (newChrom == oldChrom) {
imageV2.markAsDirtyPage();
imageV2.navigateInPlace("position="+encodeURIComponent(newPos), null, false);
window.scrollTo(0,0);
return false;
}
// If chrom changed AND there are vis updates waiting...
- if (vis.cartUpdatesWaiting()) {
+ if (cart.updatesWaiting()) {
var url = "hgTracks?db=" + getDb() + "&position=" + newPos + "&hgsid="+getHgsid();
- url = vis.cartUpdatesAddToUrl(url)
+ url = cart.addUpdatesToUrl(url)
window.location.assign(url)
return false;
}
return true;
});
// Have vis box changes update cart through ajax. This helps keep page/cart in sync.
vis.initForAjax();
// We reach here from these possible paths:
// A) Forward: Full page retrieval: hgTracks is first navigated to (or chrom change)
// B) Back-button past a full retrieval (B in: ->A,->b,->c(full page),->d,<-c,<-B(again))
// B1) Dirty page: at least one non-position change (e.g. 1 track vis changed in b)
// B2) Clean page: only position changes from A->b->|
var curPos = encodeURIComponent(genomePos.get().replace(/,/g,''));