The Page Not Found Blog – Page 5 – Living life one line of code at a time

Easy automation of JavaScript form testing

If you are writing unit tests that provide coverage for HTML forms then there is an easy, pure JavaScript way to automate testing of the underlying code that works on modern browsers. The nice thing about this approach is you don’t have to manually load a file every time you run the tests. You still need to test the HTML interface components but that’s a topic for a different blog post.

The concept is straightforward in that you need to emulate the underlying functionality of an HTML form. The good news is you don’t have to programmatically create an HTML Form or Input element. Here’s the pattern you need to follow:

Create an xhr request to retrieve the file. Be sure to set the response type as blob.
Take the xhr.response and create a new File Object using the File API.
Inject the File Object into a fake Form Object or,
You can also use FormData() to create an actual Form Object.
The fake Form Object is now ready to pass into your unit tests. Cool!

Here’s how you create a JavaScript FormData Object. Depending on what data your code expects you can add additional key/value pairs using append():

var formData = new FormData();
formData.append("files",/* file array */files);

And, here’s what the basic pattern looks like to retrieve the file, process it and then make it available for your unit tests:


var formNode; // Unit tests can access form node via this global

function retrieveFile(){

    var xhr = new XMLHttpRequest();
    xhr.open("GET","images/blue-pin.png",true); //set path to any file
    xhr.responseType = "blob"; 

    xhr.onload = function()
    {
        if( xhr.status === 200)
        {
            var files = []; // This is our files array

            // Manually create the guts of the File
            var blob = new Blob([this.response],{type: this.response.type});
            var bits = [blob,"test", new ArrayBuffer(blob.size)];

            // Put the pieces together to create the File.
            // Typically the raw response Object won't contain the file name
            // so you may have to manually add that as a property.
            var file = new File(bits,"blue-pin.png",{
                lastModified: new Date(0),
                type: this.response.type
            });

            files.push(file);

            // In this pattern we are faking a form object
            // and adding the files array to it.
            formNode = {
                elements:[
                    {type:"file",
                        files:files}
                ]
            };

            // Last, now run your unit tests
            runYourUnitTestsNow();
        }
        else
        {
            console.log("Retrieve file failed");
        }
    };
    xhr.onerror = function(e)
    {
        console.log("Retrieved file failed: " + JSON.stringify(e));
    };

    xhr.send(null);
}

HTML5 Geolocation API: Getting the best single location

The Geolocation API is built into all modern mobile browsers and it lets you take either a quick, onetime snapshot, or you can get continuous location updates. Using the browser to get your approximate location is very, very cool, but it’s also fraught with many challenges. The vast majority of blog posts on this API talk about what it can do, this blog post focuses on how to best use it and understanding the data provided by the API.

To start things out, let’s take a quick look at a short list of some of the challenges when using the Geolocation API.

Challenge 1. You will not know where the location information is coming from. There’s no way to tell if it’s from the GPS, the cellular provider or the browser vendors location service. If you care about these things then the native Android SDK, for example, gives you a huge amount of control over what they call ‘location providers.’

Challenge 2. You cannot force the app to stay open. This means that the typical user has to keep tapping the app to keep it alive otherwise the screen will go to sleep and minimize your app.

Challenge 3. Speaking about minimizing apps, when the browser is minimized the geolocation capabilities stop working. If you have a requirement for the app to keep working in the background then you’ll need to go native.

Challenge 4. You’ll have very limited control over battery usage. Second only to the screen on your phone or tablet, the current generation of GPS chips are major energy hogs and can suck down your battery very quickly. Since the Geolocation API gives you very little control over how it works you cannot build much efficiency into your apps.

Challenge 5. Most smartphones and tablets use a consumer-grade GPS chip and antenna, and that limits the potential accuracy and precision. On average, the best possible accuracy is typically between 3 and 10 meters, or 10 – 33 feet. This is based on my own extensive experience building GPS-based mobile apps and working with many customers who are also using mobile apps. Under the most ideal scenario, the device will be kept stationary in one location until the desired accuracy number is achieved.

What’s it good for? Okay, you may be wondering what is browser-based geolocation good for? It’s perfect for very simple use cases that don’t require much accuracy. If you need to map manhole covers, or parking spaces, or any other physical things that are close together you’ll need a GPS device with professional-level capabilities.

Here are a few generic examples that I think are ideal for HTML5 Geolocation:

Simply getting your approximate location in latitude/longitude and converting it to a physical address.
Finding an approximate starting location for searching nearby places or things in a database or for getting one-time driving directions.
Determining which zip code, city or State you are in to enable specific features in the app.
Getting the approximate location of a decently sized geological feature such as a park, a building, a pond, a parking lot, a driveway, a group of trees, an intersection, etc.

What’s the best way to get a single location? The best way to get a single location is to not use getCurrentPosition() but to use watchPosition() and analyze the data for a minimum set of acceptable values.

Why? Because getCurrentPosition() simply forces the browser to barf up the best available raw, location snapshot right now. It literally forces a location out of the phone. Accuracy values can be wildly inaccurate, especially if the GPS hasn’t warmed up, or if you aren’t near a WiFi with your WiFi turned on, or if your cellular provider can’t get a good triangulation fix on your phone, or it returns a cached value from a different location altogether. There are many, many “what ifs?”

So, I recommend using watchPosition() and firing it off and letting it run until the return values meet some minimum criteria that you set. You need to know that while this is happening the location values returned may cover a fairly wide geographic area…remember our best accuracy values are 10 – 30 meters. Here’s a real-world example of Geolocation API location values that I captured over a 5 minute period while standing stationary in front of a building.

What steps do you recommend? Here are five basic steps to help guide you towards one approach for getting the best location. This is a very simplistic approach and may not be appropriate for all use cases, but I think it’s adequate to demonstrate the basic concepts for working towards determining the best possible location.

Step 1. Immediately reject any values that have accuracy above a certain threshold that you determine. For example, let’s say we’ll reject any values with an accuracy reading greater than 50 meters.

Step 2. Create three arrays, one for accuracy, latitude and longitude. If the accuracy is below your threshold, or in this case < 50 meters, then push the values to the appropriate arrays. You will also need to set a maximize size for the array and create a simple algorithm for adding new values and removing old ones.

The array length could be 10, 20 or even 100 or more entries. Just keep in mind that the longer the array, the longer it will take to fill up and the longer the user will have to wait for the end result.

Step 3. Start calculating the average values for accuracy, latitude and longitude.

Step 4. Start calculating the standard deviation for accuracy, latitude and longitude.

Step 5. If your arrays fill up to the desired length and the average accuracy meets your best-possible criteria, and the standard deviation is acceptable then you can take the average latitude, longitude values as your approximate location.

For an example of this simple algorithm at work visit the following URL on your phone and step outside to get a clear view of the sky: https://esri.github.io/html5-geolocation-tool-js/field-location-template.html. [Updated link: Oct. 27, 2015]

How to know a company takes your online security seriously.

After the news last summer about a measly 1.2 billion usernames and passwords being stolen I started doing my own research on Fortune 1000 companies that I do business with. I say measly because many large companies have downplayed the importance of protecting passwords. As far as basic password security the vast majority of them failed. By password security I mean how well will it hold up when it goes head-to-head with a super-powerful, cloud-based password cracker.

There is a very easy test that you can do as well. Simply go to the company’s website and attempted to reset your password.

The main problem is that login-based security enforcement is random and everyone does it somewhat differently. Some companies may do an excellent job of login and password security and other may not. And, yes, passwords are an antiquated, 20th century invention that’s unfortunately lived well past its useful lifespan. However, the usage of them is still so widely accepted that we as consumers are stuck with them for now. So I believe it’s up to us, the consumer, to also voice our opinions of what’s acceptable and what’s not rather than leave companies to go about their business without any feedback.

Companies with failing grades will have the following password characteristics:

Allow fewer than 15 characters
Limited you to letters only
Don’t allow upper and lower case letters
Limited you to alpha-numeric only with no special characters
Provided no password strength meter. Good ones are not security theater and consumers appreciate the instant feedback
Provided no hints on how to create a strong password
Blocked the pasting of passwords. This really discourages having longer passwords.
Don’t offer two-factor authentication
Don’t provide you the option to view your password that you typed. The vast majority of us are in the privacy of our office or home when type passwords. Seeing what you typed, especially if you get it wrong is a huge time and frustration saver.
Don’t track which computer you use and log IP addresses, dates and times of access.
Don’t allow you to register a specific computer or device.
Don’t enforce HTTPS. Any company that houses your secure data should enforce secure HTTP. It’s very rare these days, but it does happen.
?? If you have other characteristics not listed here let me know.

Most of the Fortune 1000 companies I do business easily have some (or most) of the above characteristics. The problem is this creates a honey pot for bad guys who know that a company allows very-easy-to-crack passwords. In my opinion, it’s certainly an advertisement for would-be criminals looking for easy pickings especially if they can simply steal a huge chunk of the company’s database.

Where did I get the 15 character minimum number? It’s basic math. The longer and more complex a password the harder it is to crack. At 15 characters you are talking about some serious and expensive computing power. For example, a simple all lower case password of “abcdefghijklmno” could take a few months to hack using a super massive password cracker according to https://www.grc.com/haystack.htm. That’s potentially a very expensive proposition for cracking large numbers of passwords. In comparison, a complex six-character password combing lower case letters, upper case letters, numbers and special characters “a1C&qZ” might take all of a few seconds to crack. Hmmm, if there are a decent percentage of short passwords in a database that might make it a viable target for the bad guys and certainly easy pickings.

Who cares about passwords? I’ve seen many comments from large companies poo-pooing the need for complex passwords and saying they have far more important security issues to worry about. My retort is I totally disagree. Password security is the least common dominator in today’s world. It’s common knowledge that many crimes happen because there was an easy opportunity. Easy to crack passwords are no different than leaving your car or house door unlocked, or leaving your car window open with a laptop sitting on the front seat.

What type of information are we talking about here that hackers are getting access to? I’m not trying to over dramatize this but we are talking about very personal information as proven in recent data breaches that include but are not limited to: your social security number, date and place of birth, bank login information, private conversations with a doctor or hospital, credit card account information, information on when you’ll be out of town, business dealings, corporate secrets, investments and oh so much more.

And, yeah, I know that consumers can whine about having to be bothered with complex passwords. I too hate having to manually create long, complex passwords especially on a site that enforces what seem like ridiculously twisted rules. However, there is a great solution…password vault apps! PC Magazine, for one, reviews these apps and they range from free to approximately $60. You can also share some of these apps between your laptop, phone and tablet.

Conclusion. Whom do you think a bad guy would target first, a large company that allows easy and short passwords or a large company that enforces good password security and they encrypt their passwords on the database server?

My recommendation is if your company has weak user password security then write the CEO of the company and tell them that password strength does matter and that’s it’s one more piece of armor to help protect all of their systems. Don’t waste your time on filling out the standard blah-blah feedback form. Complain to the top management since they have the power to make changes.

And use a password vault when you can. It will make managing complex passwords oh so much easier.

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