Fix issues with asynchronous scraping and XMLHttpRequest

This commit is contained in:
Simon Kornblith 2006-06-02 23:53:42 +00:00
parent c42991a5bf
commit 93652a137c
3 changed files with 106 additions and 62 deletions

View file

@ -211,31 +211,36 @@ Scholar.Ingester.Interface._deleteDocument = function(browser) {
* Callback to be executed when scraping is complete
*/
Scholar.Ingester.Interface._finishScraping = function(documentObject) {
Scholar.Ingester.Interface.scrapeProgress.changeHeadline(Scholar.getString("ingester.scrapeComplete"));
var fields = Scholar.ItemFields.getItemTypeFields(documentObject.item.getField("itemTypeID"));
if(documentObject.item) {
Scholar.Ingester.Interface.scrapeProgress.changeHeadline(Scholar.getString("ingester.scrapeComplete"));
var titleLabel = Scholar.getString("itemFields.title") + ":"
Scholar.Ingester.Interface.scrapeProgress.addResult(titleLabel, this.item.getField("title"));
var creators = documentObject.item.numCreators();
if(creators) {
for(var i=0; i<creators; i++) {
var creator = documentObject.item.getCreator(i);
var label = Scholar.getString("creatorTypes."+Scholar.CreatorTypes.getTypeName(creator.creatorTypeID)) + ":";
var data = creator.firstName + ' ' + creator.lastName;
Scholar.Ingester.Interface.scrapeProgress.addResult(label, data);
}
}
for(i in fields) {
var data = documentObject.item.getField(fields[i]);
if(data) {
var name = Scholar.ItemFields.getName(fields[i]);
if(name != "source") {
var label = Scholar.getString("itemFields."+ name) + ":";
var fields = Scholar.ItemFields.getItemTypeFields(documentObject.item.getField("itemTypeID"));
var titleLabel = Scholar.getString("itemFields.title") + ":"
Scholar.Ingester.Interface.scrapeProgress.addResult(titleLabel, this.item.getField("title"));
var creators = documentObject.item.numCreators();
if(creators) {
for(var i=0; i<creators; i++) {
var creator = documentObject.item.getCreator(i);
var label = Scholar.getString("creatorTypes."+Scholar.CreatorTypes.getTypeName(creator.creatorTypeID)) + ":";
var data = creator.firstName + ' ' + creator.lastName;
Scholar.Ingester.Interface.scrapeProgress.addResult(label, data);
}
}
for(i in fields) {
var data = documentObject.item.getField(fields[i]);
if(data) {
var name = Scholar.ItemFields.getName(fields[i]);
if(name != "source") {
var label = Scholar.getString("itemFields."+ name) + ":";
Scholar.Ingester.Interface.scrapeProgress.addResult(label, data);
}
}
}
} else {
Scholar.Ingester.Interface.scrapeProgress.changeHeadline(Scholar.getString("ingester.scrapeError"));
Scholar.Ingester.Interface.scrapeProgress.addDescription(Scholar.getString("ingester.scrapeErrorDescription"));
}
setTimeout(function() { Scholar.Ingester.Interface.scrapeProgress.fade() }, 2000);
@ -311,6 +316,19 @@ Scholar.Ingester.Interface.Progress.prototype.addResult = function(label, data)
this.table.appendChild(tr);
}
Scholar.Ingester.Interface.Progress.prototype.addDescription = function(description) {
var descriptionNode = this.document.createTextNode(description);
var tr = this.document.createElement("tr");
var descriptionTd = this.document.createElement("td");
descriptionTd.style.fontSize = '10px';
descriptionTd.style.colspan = '2';
descriptionTd.appendChild(descriptionNode);
tr.appendChild(descriptionTd);
this.table.appendChild(tr);
}
Scholar.Ingester.Interface.Progress.prototype.fade = function() {
// Icky, icky hack to keep objects
var me = this;

View file

@ -200,46 +200,55 @@ Scholar.Ingester.Utilities.prototype.collectURLsWithSubstring = function(doc, su
// essential components for Scholar and would take a great deal of effort to
// implement. We can, however, always implement them later.
// It looks like these are simple front-ends for XMLHttpRequest. They're a
// component of the Piggy Bank API, so they're implemented here.
Scholar.Ingester.Utilities.HTTPUtilities = function() {}
Scholar.Ingester.Utilities.HTTPUtilities.prototype.doGet = function(url, onStatus, onDone) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.open('GET', url, true);
xmlhttp.overrideMimeType("text/xml");
xmlhttp.onreadystatechange = function() {
Scholar.Ingester.Utilities.HTTPUtilities.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(null);
// These are front ends for XMLHttpRequest. XMLHttpRequest can't actually be
// accessed outside the sandbox, and even if it could, it wouldn't let scripts
// access across domains, so everything's replicated here.
Scholar.Ingester.HTTPUtilities = function(contentWindow) {
this.window = contentWindow;
}
Scholar.Ingester.Utilities.HTTPUtilities.prototype.doPost = function(url, body, onStatus, onDone) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.open('POST', url, true);
xmlhttp.overrideMimeType("text/xml");
xmlhttp.onreadystatechange = function() {
Scholar.Ingester.Utilities.HTTPUtilities.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(body);
Scholar.Ingester.HTTPUtilities.prototype.doGet = function(url, onStatus, onDone) {
var xmlhttp = new this.window.XMLHttpRequest();
xmlhttp.open('GET', url, true);
xmlhttp.overrideMimeType("text/xml");
var me = this;
xmlhttp.onreadystatechange = function() {
me.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(null);
}
Scholar.Ingester.HTTPUtilities.prototype.doPost = function(url, body, onStatus, onDone) {
var xmlhttp = new this.window.XMLHttpRequest();
xmlhttp.open('POST', url, true);
xmlhttp.overrideMimeType("text/xml");
var me = this;
xmlhttp.onreadystatechange = function() {
me.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(body);
}
Scholar.Ingester.Utilities.HTTPUtilities.prototype.doOptions = function(url, body, onStatus, onDone) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.open('OPTIONS', url, true);
xmlhttp.overrideMimeType("text/xml");
xmlhttp.onreadystatechange = function() {
Scholar.Ingester.Utilities.HTTPUtilities.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(body);
Scholar.Ingester.HTTPUtilities.prototype.doOptions = function(url, body, onStatus, onDone) {
var xmlhttp = new this.window.XMLHttpRequest();
xmlhttp.open('OPTIONS', url, true);
xmlhttp.overrideMimeType("text/xml");
var me = this;
xmlhttp.onreadystatechange = function() {
me.stateChange(xmlhttp, onStatus, onDone);
};
xmlhttp.send(body);
}
// Possible point of failure; for some reason, this used to be a separate
// class, so make sure it works
Scholar.Ingester.Utilities.HTTPUtilities.prototype.stateChange = function(xmlhttp, onStatus, onDone) {
Scholar.Ingester.HTTPUtilities.prototype.stateChange = function(xmlhttp, onStatus, onDone) {
switch (xmlhttp.readyState) {
// Request not yet made
@ -307,6 +316,8 @@ Scholar.Ingester.Utilities.HTTPUtilities.prototype.stateChange = function(xmlhtt
*/
Scholar.Ingester.Document = function(browserWindow){
this.browser = browserWindow;
this.appSvc = Cc["@mozilla.org/appshell/appShellService;1"]
.getService(Ci.nsIAppShellService);
this.scraper = null
this.model = new Scholar.Ingester.Model();
this._generateSandbox();
@ -379,10 +390,11 @@ Scholar.Ingester.Document.prototype.scrapePage = function(callback) {
Components.utils.evalInSandbox(this.scraper.scraperJavaScript, scraperSandbox);
} catch(e) {
throw e+' in scraperJavaScript for '+this.scraper.label;
this._scrapePageComplete();
}
// If synchronous, call _scrapePageComplete();
if(!scraperSandbox._waitForCompletion) {
if(!this._waitForCompletion) {
this._scrapePageComplete();
}
}
@ -411,7 +423,7 @@ Scholar.Ingester.Document.prototype.scrapePage = function(callback) {
* function before returning
*/
/*`
/*
* Called when scraping (synchronous or asynchronous) is complete
*/
Scholar.Ingester.Document.prototype._scrapePageComplete = function() {
@ -420,17 +432,23 @@ Scholar.Ingester.Document.prototype._scrapePageComplete = function() {
this._scrapeCallback(this);
}
}
/*
* Generates a sandbox for scraping/scraper detection
*/
Scholar.Ingester.Document.prototype._generateSandbox = function() {
this.sandbox = new Components.utils.Sandbox(this.browser.contentDocument.location.href);
this.sandbox.browser = this.browser;
this.sandbox.doc = this.sandbox.browser.contentDocument;
this.sandbox.utilities = new Scholar.Ingester.Utilities;
this.sandbox.utilities.HTTPUtilities = new Scholar.Ingester.HTTPUtilities(this.appSvc.hiddenDOMWindow);
this.sandbox.window = this.window;
this.sandbox.model = this.model;
this.sandbox.XPathResult = Components.interfaces.nsIDOMXPathResult;
this.sandbox.wait = function(){ this._waitForCompletion = true; };
this.sandbox.done = function(){ this._scrapePageComplete(); };
var me = this;
this.sandbox.wait = function(){ me._waitForCompletion = true; };
this.sandbox.done = function(){ me._scrapePageComplete(); };
}
/*
@ -453,9 +471,15 @@ Scholar.Ingester.Document.prototype._updateDatabase = function() {
newItem.setField("publisher", this.model.data[uri][prefixDC + 'publisher']);
}
if(this.model.data[uri][prefixDC + 'year']) {
data.date = this.model.data[uri][prefixDC + 'year'].substring(
this.model.data[uri][prefixDC + 'year'].lastIndexOf(" ")+1,
this.model.data[uri][prefixDC + 'year'].length);
if(this.model.data[uri][prefixDC + 'year'].length == 4) {
newItem.setField("year", this.model.data[uri][prefixDC + 'year']);
} else {
try {
newItem.setField(this.model.data[uri][prefixDC + 'year'].substring(
this.model.data[uri][prefixDC + 'year'].lastIndexOf(" ")+1,
this.model.data[uri][prefixDC + 'year'].length));
} catch(e) {}
}
}
if(this.model.data[uri][prefixDC + 'edition']) {
newItem.setField("edition", this.model.data[uri][prefixDC + 'edition']);

View file

@ -24,4 +24,6 @@ creatorTypes.contributor = Contributor
creatorTypes.editor = Editor
ingester.scraping = Scraping Page...
ingester.scrapeComplete = Scraping Complete
ingester.scrapeComplete = Scraping Complete
ingester.scrapeError = Could Not Scrape
ingester.scrapeErrorDescription = An error occurred while scraping this page. Please try again. If this error persists, contact the scraper author.