Category: javascript

Error handling for failed network requests with service workers

Most service worker code samples show only the happy path where the fetched resource will eventually be available, eg: self.addEventListener('fetch', event => { // Skip cross-origin requests, like those for Google Analytics. if (event.request.url.startsWith(self.location.origin)) { event.respondWith( caches.match(event.request).then(cachedResponse => { if (cachedResponse) { return cachedResponse; } return caches.open(RUNTIME).then(cache => { return fetch(event.request).then(response => { // Put … Continue reading Error handling for failed network requests with service workers →

Secure messaging in the browser

By observing news and public discussions I feel that there is a growing awareness of data privacy and an increasing demand for secure person-to-person communication. In order to address my communication needs, I plugged together a few Javascript libraries and started the Webencryption [1] project on Github. What is Webencryption? Webencryption is a rather crude … Continue reading Secure messaging in the browser →

Advanced web security topics

(Last update 28 February 2018) This post discusses web security issues that I come across - so far thankfully mostly by reading about them. It is a work in progress which I'll keep updating. The post title includes "advanced" because the topics discussed here involve clever, non-trivial hacks, are novel at the time of their … Continue reading Advanced web security topics →

Heisenbugs with angular.js and Internet Explorer 9 or: missing console.log

I'm developing a proof of concept web application based on angular.js for corporate users, which - as so often in my career - means that they are using Internet Explorer. Several users complained about sporadic failures which were really hard to pin down, but during debugging sessions boiled down to a simple observation: the errors … Continue reading Heisenbugs with angular.js and Internet Explorer 9 or: missing console.log →

AngularJS, Internet Explorer 9 and watch error

While working on an enterprise project (of course...) I run into an error with Angular (1.3.13), Internet Explorer 9 and $watch-ing a scope when programming a directive:   TypeError: Object doesn't support property or method 'watch' I'll never find out what the reason is. The collective wisdom of Angular users claims that including JQuery solves … Continue reading AngularJS, Internet Explorer 9 and watch error →

Programmatically selecting a tab with angularjs and bootstrapui

Let's say you want to programmatically select a tab with angularjs and bootstrap ui: [CODE MISSING] According to the documentation for 3.1.1 it should be enough to modify the model; here controller.tabUsers or controller.tabGroups. Only: it doesn't work. We'll never know why. The way out is simulating the click with jquery: $("#tab_users a").trigger("click");

Replacing social sharing buttons with javascript-less alternatives

Social sharing widgets slow down page loading For every public facing site there comes the moment where its content has to be shared in social media. We all know the dreaded "Like" or "Tweet" buttons on many sites or blogs. They not only compete for the reader's attention but also for screen real estate and … Continue reading Replacing social sharing buttons with javascript-less alternatives →

Internet Explorer, zooming and resize events

My current project (cat4trad) for the European Parliament, which involves heavily GWT and javascript in bringing a seamless user experience to translators, we frequently run into issues with different browsers. The one I run into today was about a window resize event not being detected by IE8 and IE9. This simple test should always print … Continue reading Internet Explorer, zooming and resize events →