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@lfryc
Forked from jhuska/xhrhalter.js
Created June 9, 2014 17:12
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window.Graphene = window.Graphene || {};
window.Graphene.Page = window.Graphene.Page || {};
window.Graphene.Page.XHRHalter = (function() {
var STATE_CONSTRUCT = -3,
STATE_OPEN = -2,
STATE_SEND = -1,
STATE_UNITIALIZED = 0,
STATE_LOADING = 1,
STATE_LOADED = 2,
STATE_INTERACTIVE = 3,
STATE_COMPLETE = 4,
_instances = new Array(),
_associations = {},
_haltCounter = 0,
_enabled = true;
function HaltedXHR(xhr) {
if (this.id === undefined) {
_instances.push(this);
this.id = _instances.length - 1;
}
this.currentState = STATE_CONSTRUCT;
this.lastAvailableState = STATE_CONSTRUCT;
this.availableStates = new Array();
this.continueToState = STATE_CONSTRUCT;
this.xhr = xhr;
this.sendParams = {};
this.xhrParams = new Array();
this._proceeds = {};
this.tryProcessStates = function() {
while (this.currentState < this.continueToState && this.currentState < this.getLastAvailableState()) {
this.currentState += 1;
this.processState(this.currentState);
}
};
this.processState = function(state) {
if (this.currentState > 0 && this.availableStates[state] === undefined) {
return;
}
this.loadXhrParams(state);
if (this._proceeds[state]) {
this._proceeds[state]();
}
this.loadXhrParams(this.lastAvailableState);
};
this.getLastAvailableState = function() {
return this.availableStates.length - 1;
};
this.loadXhrParams = function(state) {
state = Math.max(state, STATE_UNITIALIZED);
var holder = this.availableStates[state];
this.xhr.readyState = state;
this.xhr.responseText = holder.responseText;
this.xhr.responseXML = holder.responseXML;
this.xhr.status = holder.status;
this.xhr.statusText = holder.statusText;
this.xhr.onreadystatechange = holder.onreadystatechange;
};
this.saveXhrParams = function() {
this.lastAvailableState = Math.max(this.lastAvailableState, this.xhr.readyState);
this.availableStates[this.xhr.readyState] = {};
var holder = this.availableStates[this.xhr.readyState];
holder.responseText = this.xhr.responseText;
holder.responseXML = this.xhr.responseXML;
holder.status = this.xhr.status;
holder.statusText = this.xhr.statusText;
holder.onreadystatechange = this.xhr.onreadystatechange;
};
this.isXhrCompleted = function() {
return this.currentState === STATE_COMPLETE;
};
this.wait = function() {
var that = this;
this.tryProcessStates();
if (!this.isXhrCompleted()) {
setTimeout(function() {
that.wait.call(that);
}, 100);
}
};
this.saveXhrParams();
}
return {
setEnabled: function(enabled) {
_enabled = enabled;
},
isEnabled: function() {
return _enabled;
},
getHandle: function() {
if (this.isHandleAvailable()) {
return _haltCounter++;
}
return -1;
},
isHandleAvailable: function() {
return _instances.length - 1 >= _haltCounter;
},
continueTo: function(id, state) {
var halter = _instances[id];
if (state < halter.continueToState) {
throw new Error("cannot continue to state (" + state + ") before the actual state (" + halter.continueToState + ")");
}
halter.continueToState = state;
},
isWaitingForSend: function(id) {
var halter = _instances[id];
return halter.currentState === STATE_OPEN && halter.continueToState === STATE_OPEN;
},
install: function() {
window.Graphene.xhrInterception.onConstruct( function(context) {
var xhr = context.proceed();
if (_enabled) {
var halter = _associations[xhr] = new HaltedXHR(xhr);
halter.wait();
}
return xhr;
});
window.Graphene.xhrInterception.onOpen( function(context) {
var halter = _associations[context.xhrOriginal];
if (halter !== undefined) {
halter.saveXhrParams();
halter._proceeds[STATE_OPEN] = context.proceed;
} else {
return context.proceed();
}
});
window.Graphene.xhrInterception.onSend( function(context) {
var halter = _associations[context.xhrOriginal];
if (halter !== undefined) {
halter.sendParams = arguments;
halter.saveXhrParams();
halter._proceeds[STATE_SEND] = context.proceed;
} else {
return context.proceed();
}
});
window.Graphene.xhrInterception.onreadystatechange( function(context) {
var halter = _associations[context.xhrOriginal];
if (halter !== undefined) {
halter.saveXhrParams();
halter._proceeds[context.xhrOriginal.readyState] = context.proceed;
} else {
return context.proceed();
}
});
}
};
})();
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