Wow.\u00a0 I think I got it.\u00a0 I’ve got a Firefox plugin that can suppress all alert() dialogs on a page if the user checks a “suppress” box on the second alert() dialog.<\/p>\n
The trick, was not to rely on the DOMContentLoaded event to fire to do the override.\u00a0 Instead, I used the DOMWillOpenModalDialog to detect the first alert().\u00a0 After detection, I overrode with an alertCheck which asked the user whether or not to “suppress more dialogs”.\u00a0 If the user answers in the affirmative, alert() is simply overwritten with an empty function.<\/p>\n
Piece of cake.<\/p>\n
A couple of issues though…<\/p>\n
In order to override the alert() function, I have to write to document.getElementById(‘content’).contentWindow.wrappedJSObject.alert.<\/p>\n
Remember how I mentioned the distance<\/em> between the Extension JavaScript, and the inline content JavaScript?\u00a0 I said it felt like a security layer.<\/p>\n I was totally right.<\/p>\n Check this out.<\/a> I’ll quote:<\/p>\n You should be aware of XPCNativeWrappers<\/a> when working with untrusted content<\/a>. With XPCNativeWrappers turned on (which is the default in Firefox 1.5+), your extension can safely access the DOM of the content document, but not the content JavaScript. Bypassing XPCNativeWrapper to work with content JavaScript directly can lead to security problems.<\/p><\/blockquote>\n Hrmph.\u00a0 So I seem to be violating some security rules here.\u00a0 So maybe my approach isn’t the greatest idea.\u00a0 “Mook” from irc.mozilla.net #extdev suggested looking into commonDialog.xul…but I can’t seem to wrap my head around that just yet.<\/p>\n Not sure why yet, but while I can suppress dialog floods like this:<\/p>\n It seems to fail on this:<\/p>\n For some reason, regardless of whether or not I choose to suppress the dialogs, they just keep coming.\u00a0 It works fine when I swap out the confirm() for a second alert().\u00a0 Not exactly sure why.\u00a0 Yet.<\/p>\n Ok, so I’m going to clean the code up, and post it soon.\u00a0 I’ll also post a link to a real, brutally annoying website where you can test the alertCheck extension.\u00a0 Just give me a bit.<\/p>\n","protected":false},"excerpt":{"rendered":" Wow.\u00a0 I think I got it.\u00a0 I’ve got a Firefox plugin that can suppress all alert() dialogs on a page if the user checks a “suppress” box on the second alert() dialog. The trick, was not to rely on the DOMContentLoaded event to fire to do the override.\u00a0 Instead, I used the DOMWillOpenModalDialog to detect […]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[380,5,220,44,68,51,79],"tags":[207,210,214,219,216,217,208,125,1212,35,209,212,218],"class_list":["post-387","post","type-post","status-publish","format-standard","hentry","category-alertcheck-firefox-extensions-technology","category-computer-science","category-firefox-extensions","category-internet","category-javascript","category-security","category-technology","tag-alert","tag-alertcheck","tag-contentalert","tag-contentwindow","tag-domcontentloaded","tag-domwillopenmodaldialog","tag-dos","tag-firefox","tag-javascript","tag-mozilla","tag-override","tag-windowalert","tag-wrappedjsobject"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/prmTy-6f","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/posts\/387","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/comments?post=387"}],"version-history":[{"count":5,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/posts\/387\/revisions"}],"predecessor-version":[{"id":669,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/posts\/387\/revisions\/669"}],"wp:attachment":[{"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/media?parent=387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/categories?post=387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mikeconley.ca\/blog\/wp-json\/wp\/v2\/tags?post=387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Imperfections<\/h2>\n
for (i = 0; i < 10; ++i) {\r\n alert(i);\r\n}<\/pre>\nfor (i = 0; i < 10; ++i) {\r\n alert(i);\r\n confirm(i);\r\n}<\/pre>\n