dojo.provide("dojo.undo.browser");
dojo.require("dojo.io.common");
try{
if((!djConfig["preventBackButtonFix"])&&(!dojo.hostenv.post_load_)){
document.write("<iframe style='border: 0px; width: 1px; height: 1px; position: absolute; bottom: 0px; right: 0px; visibility: visible;' name='djhistory' id='djhistory' src='"+(dojo.hostenv.getBaseScriptUri()+'iframe_history.html')+"'></iframe>");
}
}catch(e){/* squelch */}
if(dojo.render.html.opera){
dojo.debug("Opera is not supported with dojo.undo.browser, so back/forward detection will not work.");
}
dojo.undo.browser = {
initialHref: (!dj_undef("window")) ? window.location.href : "",
initialHash: (!dj_undef("window")) ? window.location.hash : "",
moveForward: false,
historyStack: [],
forwardStack: [],
historyIframe: null,
bookmarkAnchor: null,
locationTimer: null,
/**
*
*/
setInitialState: function(/*Object*/args){
//summary: Sets the state object and back callback for the very first page that is loaded.
//description: It is recommended that you call this method as part of an event listener that is registered via
//dojo.addOnLoad().
//args: Object
// See the addToHistory() function for the list of valid args properties.
this.initialState = this._createState(this.initialHref, args, this.initialHash);
},
//FIXME: Would like to support arbitrary back/forward jumps. Have to rework iframeLoaded among other things.
//FIXME: is there a slight race condition in moz using change URL with the timer check and when
// the hash gets set? I think I have seen a back/forward call in quick succession, but not consistent.
addToHistory: function(args){
//summary: adds a state object (args) to the history list. You must set
//djConfig.preventBackButtonFix = false to use dojo.undo.browser.
//args: Object
// args can have the following properties:
// To support getting back button notifications, the object argument should implement a
// function called either "back", "backButton", or "handle". The string "back" will be
// passed as the first and only argument to this callback.
// - To support getting forward button notifications, the object argument should implement a
// function called either "forward", "forwardButton", or "handle". The string "forward" will be
// passed as the first and only argument to this callback.
// - If you want the browser location string to change, define "changeUrl" on the object. If the
// value of "changeUrl" is true, then a unique number will be appended to the URL as a fragment
// identifier (http://some.domain.com/path#uniquenumber). If it is any other value that does
// not evaluate to false, that value will be used as the fragment identifier. For example,
// if changeUrl: 'page1', then the URL will look like: http://some.domain.com/path#page1
// Full example:
// dojo.undo.browser.addToHistory({
// back: function() { alert('back pressed'); },
// forward: function() { alert('forward pressed'); },
// changeUrl: true
// });
//
// BROWSER NOTES:
// Safari 1.2:
// back button "works" fine, however it's not possible to actually
// DETECT that you've moved backwards by inspecting window.location.
// Unless there is some other means of locating.
// FIXME: perhaps we can poll on history.length?
// Safari 2.0.3+ (and probably 1.3.2+):
// works fine, except when changeUrl is used. When changeUrl is used,
// Safari jumps all the way back to whatever page was shown before
// the page that uses dojo.undo.browser support.
// IE 5.5 SP2:
// back button behavior is macro. It does not move back to the
// previous hash value, but to the last full page load. This suggests
// that the iframe is the correct way to capture the back button in
// these cases.
// Don't test this page using local disk for MSIE. MSIE will not create
// a history list for iframe_history.html if served from a file: URL.
// The XML served back from the XHR tests will also not be properly
// created if served from local disk. Serve the test pages from a web
// server to test in that browser.
// IE 6.0:
// same behavior as IE 5.5 SP2
// Firefox 1.0+:
// the back button will return us to the previous hash on the same
// page, thereby not requiring an iframe hack, although we do then
// need to run a timer to detect inter-page movement.
//If addToHistory is called, then that means we prune the
//forward stack -- the user went back, then wanted to
//start a new forward path.
this.forwardStack = [];
var hash = null;
var url = null;
if(!this.historyIframe){
this.historyIframe = window.frames["djhistory"];
}
if(!this.bookmarkAnchor){
this.bookmarkAnchor = document.createElement("a");
dojo.body().appendChild(this.bookmarkAnchor);
this.bookmarkAnchor.style.display = "none";
}
if(args["changeUrl"]){
hash = "#"+ ((args["changeUrl"]!==true) ? args["changeUrl"] : (new Date()).getTime());
//If the current hash matches the new one, just replace the history object with
//this new one. It doesn't make sense to track different state objects for the same
//logical URL. This matches the browser behavior of only putting in one history
//item no matter how many times you click on the same #hash link, at least in Firefox
//and Safari, and there is no reliable way in those browsers to know if a #hash link
//has been clicked on multiple times. So making this the standard behavior in all browsers
//so that dojo.undo.browser's behavior is the same in all browsers.
if(this.historyStack.length == 0 && this.initialState.urlHash == hash){
this.initialState = this._createState(url, args, hash);
return;
}else if(this.historyStack.length > 0 && this.historyStack[this.historyStack.length - 1].urlHash == hash){
this.historyStack[this.historyStack.length - 1] = this._createState(url, args, hash);
return;
}
this.changingUrl = true;
setTimeout("window.location.href = '"+hash+"'; dojo.undo.browser.changingUrl = false;", 1);
this.bookmarkAnchor.href = hash;
if(dojo.render.html.ie){
url = this._loadIframeHistory();
var oldCB = args["back"]||args["backButton"]||args["handle"];
//The function takes handleName as a parameter, in case the
//callback we are overriding was "handle". In that case,
//we will need to pass the handle name to handle.
var tcb = function(handleName){
if(window.location.hash != ""){
setTimeout("window.location.href = '"+hash+"';", 1);
}
//Use apply to set "this" to args, and to try to avoid memory leaks.
oldCB.apply(this, [handleName]);
}
//Set interceptor function in the right place.
if(args["back"]){
args.back = tcb;
}else if(args["backButton"]){
args.backButton = tcb;
}else if(args["handle"]){
args.handle = tcb;
}
var oldFW = args["forward"]||args["forwardButton"]||args["handle"];
//The function takes handleName as a parameter, in case the
//callback we are overriding was "handle". In that case,
//we will need to pass the handle name to handle.
var tfw = function(handleName){
if(window.location.hash != ""){
window.location.href = hash;
}
if(oldFW){ // we might not actually have one
//Use apply to set "this" to args, and to try to avoid memory leaks.
oldFW.apply(this, [handleName]);
}
}
//Set interceptor function in the right place.
if(args["forward"]){
args.forward = tfw;
}else if(args["forwardButton"]){
args.forwardButton = tfw;
}else if(args["handle"]){
args.handle = tfw;
}
}else if(dojo.render.html.moz){
// start the timer
if(!this.locationTimer){
this.locationTimer = setInterval("dojo.undo.browser.checkLocation();", 200);
}
}
}else{
url = this._loadIframeHistory();
}
this.historyStack.push(this._createState(url, args, hash));
},
checkLocation: function(){
//summary: private method. Do not call this directly.
if (!this.changingUrl){
var hsl = this.historyStack.length;
if((window.location.hash == this.initialHash||window.location.href == this.initialHref)&&(hsl == 1)){
// FIXME: could this ever be a forward button?
// we can't clear it because we still need to check for forwards. Ugg.
// clearInterval(this.locationTimer);
this.handleBackButton();
return;
}
// first check to see if we could have gone forward. We always halt on
// a no-hash item.
if(this.forwardStack.length > 0){
if(this.forwardStack[this.forwardStack.length-1].urlHash == window.location.hash){
this.handleForwardButton();
return;
}
}
// ok, that didn't work, try someplace back in the history stack
if((hsl >= 2)&&(this.historyStack[hsl-2])){
if(this.historyStack[hsl-2].urlHash==window.location.hash){
this.handleBackButton();
return;
}
}
}
},
iframeLoaded: function(evt, ifrLoc){
//summary: private method. Do not call this directly.
if(!dojo.render.html.opera){
var query = this._getUrlQuery(ifrLoc.href);
if(query == null){
// alert("iframeLoaded");
// we hit the end of the history, so we should go back
if(this.historyStack.length == 1){
this.handleBackButton();
}
return;
}
if(this.moveForward){
// we were expecting it, so it's not either a forward or backward movement
this.moveForward = false;
return;
}
//Check the back stack first, since it is more likely.
//Note that only one step back or forward is supported.
if(this.historyStack.length >= 2 && query == this._getUrlQuery(this.historyStack[this.historyStack.length-2].url)){
this.handleBackButton();
}
else if(this.forwardStack.length > 0 && query == this._getUrlQuery(this.forwardStack[this.forwardStack.length-1].url)){
this.handleForwardButton();
}
}
},
handleBackButton: function(){
//summary: private method. Do not call this directly.
//The "current" page is always at the top of the history stack.
var current = this.historyStack.pop();
if(!current){ return; }
var last = this.historyStack[this.historyStack.length-1];
if(!last && this.historyStack.length == 0){
last = this.initialState;
}
if (last){
if(last.kwArgs["back"]){
last.kwArgs["back"]();
}else if(last.kwArgs["backButton"]){
last.kwArgs["backButton"]();
}else if(last.kwArgs["handle"]){
last.kwArgs.handle("back");
}
}
this.forwardStack.push(current);
},
handleForwardButton: function(){
//summary: private method. Do not call this directly.
var last = this.forwardStack.pop();
if(!last){ return; }
if(last.kwArgs["forward"]){
last.kwArgs.forward();
}else if(last.kwArgs["forwardButton"]){
last.kwArgs.forwardButton();
}else if(last.kwArgs["handle"]){
last.kwArgs.handle("forward");
}
this.historyStack.push(last);
},
_createState: function(url, args, hash){
//summary: private method. Do not call this directly.
return {"url": url, "kwArgs": args, "urlHash": hash}; //Object
},
_getUrlQuery: function(url){
//summary: private method. Do not call this directly.
var segments = url.split("?");
if (segments.length < 2){
return null; //null
}
else{
return segments[1]; //String
}
},
_loadIframeHistory: function(){
//summary: private method. Do not call this directly.
var url = dojo.hostenv.getBaseScriptUri()+"iframe_history.html?"+(new Date()).getTime();
this.moveForward = true;
dojo.io.setIFrameSrc(this.historyIframe, url, false);
return url; //String
}
}