David J McClelland

Experiences at the Intersection of Programming & Design

Archive for the ‘Practice’ Category

nvd3 Charts Knowledge Base


Flaky Features


Chart Type



Axis Visibility Line Chart
Toggles Axis Tick Labels Function should be .showYAxisLabels
Line with Focus Chart Toggles Axis Ticks and Labels should be separate functions

Helpful nvd3 Resources


Chart Type



Tic Misalignment with dates Line Stack Overflow For round dates
Tic Misalignment with times Line  same link, further down  Time Series with .useInteractiveGuideline
Styling Chart Elements Any Github Resizing changes colors
Drawing Lifecycle Any nvd3.org
Time Series example Line GitHub Good Starter
Time Series Done Right Line jsFiddle Very Good starter
Another Time Series Example Line nvd3
D3 Formatting Github
D3 Time Formats Bostock You can’t guess them all
Angular Directives All Github Lots of option settings – Angular not required
Responsive  All Stack Overflow d3.js
Responsive All Github d3.js oriented too
Reverse X and Y All Timely Portfolio Lots of other examples
Continuous Flow Time Plunker
Click Events Any Plunker
Stack Overflow

D3 Techniques




Assign multiple attributes efficiently Stack Overflow For round dates
Groups and Transforms Stack Overflow
Cool examples rCharts


  • Filed under: Practice
  • JavaScript D3-Based Data Visualization Libraries


    D3.js is the leading drawing library for creating svg-based scalar images in browsers because it is powerful and fast. The corollary that great power comes with great responsibility holds true: D3 is said to be very difficult to learn and use well, and rewards those who can specialize in developing with it. Writing out svg seems even harder/more special then D3, but I am considering any library that uses SVG really.

    Fortunately, many charting libraries have sprung up for those who can’t specialize in D3 or what it does, but need graphs and charts in browsers -like me. Probably too many, each with its own not-quite-generic approach to a subset of chart functionality it’s creator had in mind.

    There are quite a few comparison pages offering a list of the libraries with overviews and checklists of features. These are useful at eliminating some, such as non-open source packages, canvas-only libraries etc. Many comparison sites simply list the popular choices but lack any depth beyond a blurb and URL. I was unsatisfied and started my own rating table.

    My 5-6 libraries that supported all popular chart types:

    C3 Chartist Dygraph Dimple NVD3 Rickshaw


    5K Stars









    X X X X
    12 1.4 5.7 2.5



    canvas/svg hybrid





    fussy CSS

    No legend

    No tooltips

    No Touch

    unwanted sorting,

    fussy css

    D3 pokes through dead

    I tested speed by loading 30 charts displaying a single series of 40 values as a line chart in a single browser window in IE 10. Whatever each library decided to enable as defaults was accepted and displayed. Tooltips and axis overlay effects did not appear to tip the scale: the fastest and slowest library had the same features. Animation transitions were turned off/avoided.



    NVD3 for speed, C3 for features and documentation. Dimple could be great for interactivity and animation, but strangely, it sorted by y values.

    I hear a lot about High Charts and Chart Fusion, both commercial products. They were slow and dated, but offer support and many templates. Google charts is an API-driven service which is too restrictive for use in an application.

  • Filed under: Practice
  • How to Clear Input Fields in Thingworx Composer


    There are several ways to clear input fields:

    One: Using Widget ResetToDefaultValue Property


    The arrow pointing to ResetToDefaultValue is filled because it is bound to an event.

    When to use:

    • Use if there is a single input field
    • Also use when there are other fields that should not be reset at the same time, or by the same trigger

    Two: Using Panel ResetInputsToDefaultValue Property


    When to use:

    • If there are multiple, related input fields

    Three: Using Mashup ResetInputsToDefaultValue Property


    When to use:

    • If there are multiple related input fields in multiple panels, or even if some inputs are not in panels.

    Events that usually trigger this:

    • SetProperties: it is the Composer equivalent to a form submit – after you submit a value, resetting the input signals that it is ready to take a new value
    • Reset Button click

    The click event of setProps button is wired to SetProperties. The ServiceInvokeCompleted event of SetProperties is wired to ResetToDefaultValue on the textInput Widget NumericEntry-21. A reset button could be wired directly to ResetToDefaultValue, or to the ResetInputsToDefaultValue handler of the panel or widget.


  • Filed under: Practice
  • Intellij IdeaCygWingitorange@2x

    I didn’t find much existing basic documentation on how to get started with scripting in earnest, so I decided to fill the gap with my own experience. I had never been an avid user of command windows or terminals or scripting, and I admit to complaining that Cygwin is be a confusing heap. But that hasn’t stopped me from realizing their benefits, and I am ready to give them the respect they deserve since they have saved me time and drudgery.

    Solving Script Amnesia

    A successful script automates some tedious activity on the OS and is soon forgotten. That’s my problem: when I need to write or edit a script its hard to pick up where I left off or remember arcane syntax that I don’t use anywhere else. I don’t write scripts all day, so I often don’t remember where I put it, what environment I edited in, let alone some arcane syntax and other context information.

    I should have realized a long time ago that if a script is worth writing, it is worth safeguarding and properly maintaining like any source code. But script editing happens in spurts as a means to an end – it’s hard to justify taking the time to build up an infrastructure and become more proficient. This post documents how I set up a script repository and IDE using Git, Bitbucket, IntelliJ, Cygwin and some assorted environmental variables. So this documents my effort to get a a scripting environment set up that I can get familiar with and rely on. I’ll know it’s successful if I start writing more scripts because I feel more confident that I will get a longer return from the effort.

    Before I set up my scripting environment I asked my self some questions to help determine what tools and techniques I would need, and I encourage you to do answer these as well:

    Scripting Environment Questions:

    • Portability: How portable does my script need to be?
      • What OS(s) will it run on? My case: Win/Mac/Linux
      • What user(s) will use it? Me/Coworkers/My boss/Continuous Integration
    • IDE? Can I edit my scripts in the same IDE I use for everything else? Yes (detailed follow)
    • Extensibility: If my script can’t do everything natively, is there a strategy to add functionality? (Yes, details follow)
      • For example, if your script needs to do a REST call, do you: script a browser? import a cURL library?
    • Conventions: Is there a convention I can follow to put my scripts where both the OS and I can find them without tweaking? (Yes, requires some care)
      • For example: home/user/bin

    My answers lead me to a create a setup that prioritizes flexibility across OS and users and tries to follow general conventions. So, it should work for anybody, but you can sacrifice some of the generalization for your own convenience if you want to.


    Once you combine Windows with another OS you are probably going to run into Cygwin as your go-to solution because you can write bash scripts that can run on Windows, MacOS and Linux. It is still very possible/maybe necessary to write Windows-only scripts in Cygwin. All my scripts are .sh except some narrow Windows cases.

    Portability also pertains to editing and running scripts on multiple machines in multiple user accounts. It means creating a project definition that can be put under version control to allow me to edit and run scripts on any machine as any user. To do this I followed conventions regarding where to house scripts (see Conventions below) and set my cygwin user folder as the project root and committed this to BitBucket using Git.

    IDE Support

    Maybe it should have been obvious, but it took me awhile to decide that I should strive to use my regular editor to edit scripts. I use IntelliJ, and I found a plugin called BashSupport that supports syntax highlighting, rename refactoring, documentation lookup, inspections, quickfixes and such. I can also run scripts from run configurations within IntelliJ- not sure if that is due to BashSupport or not honestly. Before that I used Notepad++, or simply Notepad. Another big advantage of using an IDE: it creates a project definition so you can reopen the project and see your scripts! Again, should have thought of this earlier, but my scripts were all small and scattered and this seemed like a heavyweight tank cracking a nut.


    Cygwin has cultivated a large library of plugins that scratch the itch of various developer needs. It is likely to cover any requirement I will have. Install Cygwin to C:\ and don’t install any optional components. Save the installer (setup-x86_64.exe in my case) in the cygwin folder inside a folder you create called installer. Cygwin will create a cache of the plugins library in there. You will need the installer if you ever decide to install a plugin, so its a good idea to keep it with the project folder instead of losing in in the downloads folder like I have done.


    Tip: In Cygwin Shortcut select Preferences: Shortcut Pane: Click Run as Administrator


    Cygwin tries to follow conventions whenever possible. It puts a directory structure that mimics Linux root, but it is located inside the Cygwin installation folder. Instead of accepting the default “Program files” location, install cygwin at C:\ to avoid spaces in any paths. My user dir is therefore: C:\cygwin64\home\[windows username]\bin. I added bin to .bashrc so I can run scripts from anywhere in Cygwin.

    Running Scripts

    From Intellij: As I mentioned, you can run shell scripts from within Intellij using run configurations. This seems like a lot of work after getting past the cool idea factor. It doesn’t open up any debugging options as far as I can tell. It’s a good idea to check the “Show this page” box to fill in any necessary arguments before running a script.


    Intellij Script Run Configuration


    Script output in Run Output of Intellij

    From Cygwin: cd bin, then ./script.sh to execute. Or add bin to .bashrc and execute script.sh from any location. Add Cygwin to context menu in Windows.

    From Git Bash: Open it from your bin directory to run a script on a Windows dev box lacking Cygwin. Otherwise useless because it is not extensible and conventional.

    You can run Cygwin in the IntelliJ terminal or in a terminal emulator like Conemu as well – Google for details.

    Polymer Data Models/Templates in Custom Elements

    A custom element can contain it’s own data source and be its own data model, as this example shows. The script provides a JavaScript object “salutations” containing a list of 4 objects with properties “what” and “who”.

    The inner template sets a repeat property that processes each “who/what” object “s” in salutations. The contents of the template is a mix of html and mustachioed object notations that results in a repeater containing labels and text inputs as shown in the inset from the resulting page.

    Source Code Explainer


    My Feature Branch

    Polymer.org Example

    Live example

  • Filed under: Practice, Tools
  • Google Maps: Set Zoom to Fit All Markers


    Zoom to fit a group of Markers

    JsFiddle is a great tool to use for experiments with Google Maps. If you want to see the map displayed in the output frame, there are a few tweaks you need to know about

    Note: Using Google Maps API V3

    map options can be minimal:

    var mapOptions = {
    mapTypeId: google.maps.MapTypeId.ROADMAP

    Use bounds global to hold outermost marker coordinates:

    var bounds = new google.maps.LatLngBounds();

    Put locations in an array “locationArray”. Iterate through them as you create markers so that each coordinate can be compared to bounds via bounds.extend in case it increases the size. Map.fitBounds(bounds) will set the zoom.

    var coord;
    for (coord in locationArray) {
    var newMarker = new google.maps.Marker({
    position: locationArray[coord],
    map: map,
    draggable: false


    Google Maps in JSFiddle


    JsFiddle is a great tool to use for experiments with Google Maps. If you want to see the map displayed in the output frame, there are a few tweaks you need to know about, which I will cover here and share in a working example. I started with an example from the excellent developer resources Google provides.

    Note: Using Google Maps API V3

    Tweak One: The Google API Library include:

    The include must be modified from the following to work in JSFiddle:


    &dummy=.js is a workaround JSFiddle uses to recognize that this is a JavaScript library when it doesn’t end with a .js suffix – paste this in instead of the default URI:


    Tweak Two: The Google examples provide a initialization call that does not work in JSFiddle:

    google.maps.event.addDomListener(window, 'load', initialize);

    replace it with this:


    (Not Really a Tweak) You must have the CSS to see the map container div:

    The html and body entries are required, the map div can be set to pixel values if you want.

    html { height: 100% }
    body { height: 100%; margin: 0; padding: 0 }



    below requires your permission to display your current location in the map. Location information does not go to this website, it goes directly to Google Maps.

    Taming Localization Resources


    I have been working in the “legacy” portion of an application lately. It is state-of-the-art Java Struts from 2000. In their zeal to separate logic and presentation, Sun made it fairly difficult to trace out the origins of specific elements on a web page back to code in the project.

    Its not that hard to find all the localization bundles that need updating using a search tool, but testing that everything got translated and put in place is going to be tough for QA and bug fixing.

    Problem: .properties files are used for localization strings but also for lots of other things in Java. How do I find just the localization ones? Nobody thought to include a marker comment like #l18n in files that require translation.

    Solution: manually check the files and update a perl script with filenames and directory names to skip. Later, write a perl script to add the comment marker to each valid string resource .property file.

    Problem: I found all the localization strings, now how do I know which ones have to be updated? How many revisions do I have to go back to get all the changes needed without paying for translating strings that were already done last time?

    Solution: If someone had thought to add a comment to the Perl script that gathers the properties deltas with the SVN revision, I would have just done a diff to that – easy. I made that my final step. But what I did was check the translated files for revision numbers and then compare them to the revision numbers of the English source. This allowed me to account for  potential changes that may have been added when the last batch of resources were still being translated.

    Key Learning: The automation of the Perl script to gather the properties and then run a diff back to an earlier commit was a timesaver, but not a replacement for manual inspection and checking of the resources. I found some properties that had never been translated and never came up as a bug in the software. I avoided getting system properties needlessly translated.

  • Filed under: Practice
  • Microsoft WebMatrix Review


    How do you respond to Free and Open Source software eating your market?

    One way is to create a user-friendly package of bite-size meals for novices to follow like a breadcrumb trail back to your nest. Include the better FOSS add-ons and make it go down easier with a polished toolset. In other words, spend money seducing developers with the aspect FOSS is weakest at- the developer experience.

    I stumbled over WebMatrix while attempting to create an API site to help with some technical editing I am doing on a book. I started out using another Microsoft tool called Web Platform Installer 4.5. WPI is a utility for managing the task of installing various parts of the Microsoft solution stack along with some FOSS that it plays with. In my opinion it suffers from the Dictionary Paradox: I don’t know what the things are it lists as I browse it: conversely, don’t know what the things are that I will need to build a particular solution. Somehow it installed WebMatrix, but I didn’t know what it was or that I had it. Here’s a synopsis. I discovered that it had installed WebMatrix after I found it via another search and started installing it.

    The most powerful aspect of WebMatrix it combines many activities that normally straddle several separate applications into a unified experience that focuses on learning and accomplishment. Instead of hunting down IIS manager, IP addresses, port numbers, default browsers, database manager, tables, Javascript libraries, Java versions, firewall settings, .NET runtimes etc. you create a simple Hello World. MySQL, IIS and a stripped-down IDE are just right for getting from 0 to trouble in an afternoon – I highly recommend it. Especially to Java tool developers.

  • Filed under: Practice
  • Install Tomcat on Mac OS


    Getting a local Tomcat server instance running on Windows was simple: install it and configure it as part of XAMPP.  Not so on Macintosh OS.

    Looking for an alternative, Googling turned up a well-written step-by-step recipe. It includes all of the steps required, from getting Java SDK, getting the right Tomcat package, changing configuration settings, to pointing out a nice little control panel to manage startup and shutdown- similar to the XAMPP control panel for Mac. Well done Wolf Paulus!

    Once I got Tomcat running I wanted to post a webapp to get a Hello World page up. This was not covered in the previous recipe, but I found a decent one that worked for me. It also covers installation for Mac, Windows and Ubuntu Linux.

  • Filed under: Practice
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