Week 8 at The Iron Yard

We continued our work in React JavaScript this week, with an introduction to Horizon and RethinkDB to facilitate placing data on a web page. Our exercise this week was to develop a chat application. At the end of class on Tuesday, I was feeling discouraged because I had worked all afternoon and not made much progress with the code. However, by the end of class Wednesday, I was making significant progress, and on Thursday I was seeing satisfactory results.

There are still some subtleties in the code that I am working to grasp. However, I realized that while I may not understand everything completely at this point, I am gaining more familiarity with the code the more I work with it.

I also had some difficulties uploading code to GitHub; again, because of not realizing the ways that GitHub handles uploaded files. Fortunately, Jim (our instructor) was able to suggest the appropriate instructions to get things working again.

I also discussed my idea for my project for “Demo Day” with Jim, and was able to define some realistic goals.

Jim says one more week of lecture, and then we begin work on our graduation projects for “Demo Day.” This promises to be exciting.

Week 7 at The Iron Yard

We continued our work on React this week. Our activities included splitting our previously written JavaScript code (in earlier assignments) into Component modules, and learning web navigation using the Router tag. We also learned how to set up scripts to install webpack functionality, and how to reference fonts within React components. I’m impressed with the results of our coding exercises: we are building more and more sophisticated web pages.

When discussing our progress for the week, one of my fellow students remarked that the times when we think, “Oh, yes, we’re getting this” are often accompanied by thoughts of, “oh, no, this is really hard and will we ever understand this?” Certainly I have felt this way, though I know from past coding experience that eventually, yes, I will understand this, and having moments when I wonder if I ever will are part of the process (though undoubtedly frustrating at the time).

In any event, looking forward to seeing what we can build next week.

Halfway There: Week Six at The Iron Yard

This week we worked on React, which is a JavaScript subset (or library) that makes coding applications more concise. In particular, it facilitates output to the web page (and input from the web page). At this stage, React seems more complex than the JavaScript it is based upon; however, as with most code, I presume this is just a matter of getting used to it.

During the week, we had a group exercise, which was enlightening not only due to the fact that working together helped us reached a result a bit faster than we might have done individually, but also because it demonstrated that those of us in the class are all pretty much at the same level in feeling challenged by the code. We are also all open to seeking out different ways of understanding and building the code, and sharing that information.

We also celebrated the fact that we’ve completed week six – halfway through the course – and took a class picture.

Star Trek Beyond review (2016)

The 50th Anniversary of Star Trek would not have been the same without an addition to the Trek universe, and Star Trek Beyond is a solid performance. It’s not the best, it’s not the worst, but it does have a lot to recommend it. (And yes, spoilers follow. Stop now if you don’t wish to see any.)

Early in the movie, Kirk and Spock are shown having second thoughts of continuing the five-year mission (it’s year three). Kirk wonders if he can live up to his father’s reputation; Spock learns of Ambassdor Spock’s death and wonders if he should continue his work on New Vulcan. The Enterprise visits a city in space called Yorktown (a spectacular special effect) and is assigned to assist a ship captain who has asked for help to get her crew back. However, this turns out to be a trap: the Enterprise is destroyed and the crew is stranded on a planet. Scott quickly encounters an ally (Jaylah), Kirk and Chekov try to get to the crashed saucer section to get technological assistance, Spock and McCoy try to find the others, Sulu and Uhura and the remainder of the crew are detained by Krall, who has a grudge against the Federation. The rest of the film finds the crew resisting Krall and preventing him from destroying the space city and its millions of inhabitants. (This involves finding and restoring an old starship which had crashed on the planet over a century before. The seatbelts on the bridge were welcome and needed in the escape. They also, interestingly, found a strategic use for music radio.)

The film has interesting references to events that had happened in previous Treks (particularly original Trek and Enterprise)—though Simon Pegg (a co-writer) seems to have forgotten about the Vulcan healing trance. The special effects are outstanding (particularly the space city and the Enterprise traveling through space at warp speed, which is brief but breathtaking). All of the the regulars have significant roles in resolving the issue, which makes Anton Yelchin’s loss keenly felt (the credits have an acknowledgement of him). I thought his Chekov was extremely well portrayed, both in the 2009 film and in this one.

Most of all, I was happy to see that Roddenberry’s overall Trek philosophy of Starfleet (and the Federation) as a representation of peaceful exploration (and not of war) was emphasized, and the point was made that resilience and strength can be developed without conflict. At the end, each member of the crew takes a line of “Space, the final frontier…,” and Uhura’s (Zoe Saldana’s) recitation of “to boldly go where no one has gone before” moved me to tears (it was wonderful!).

Let’s hope that the next film (already scheduled) does at least as well.

P.S. Though I’m standing in front of an IMAX poster for Star Trek: Beyond, I saw it in 3D. (Not because I wanted to, but because 3D was the only choice at the time I wanted to see it.)

P.P.S. Before the movie, the theater showed a brief clip of Simon Pegg (Scotty) thanking the audience for coming to see the film in a movie theater (as opposed to waiting until it was available on cable, DVD, or NetFlix, I suppose).

Web Documentation: Week Five at the Iron Yard

This week we had guest speakers. On Monday, the speaker covered the work environment for a developer (writing code for the web). Tuesday and Wednesday the speakers covered features of es6 (a 2015 update of JavaScript). Thursday the speaker covered debugging JavaScript code.

This week, a particular challenge I had was to place the code for an input box in the html file (and thus on the web page), capture the value entered into it on the web page, and transfer that value into JavaScript for processing. I spent hours (literally) searching the web for a procedure that would do it. I would follow the instructions and get error messages. I would repeatedly see comments saying “just do this” or “this would do it,” but they didn’t work, and the meaning was not clear to me. After numerous failures, I finally tried some simple input and capture code, as best as I could understand it. With the help of a classmate, Hunter Hawes, I finally got it working.

Here’s the process in brief:

In the html file, the following code places an input box with a submit button next to it on the web page. After the user enters data in that box and the user clicks on the submit button, the data is placed in the variable “number” and the function GuessNumber in the JavaScript file is called and run:

<form>
Enter number: <input type=”text” name=”number”>
<input type=”button” onClick=”GuessNumber()” value=”Submit”>
</form>

..which shows on the web page as:

Enter number:

 

In the JavaScript file, document.querySelector puts the value entered in the box on the web page (stored in the variable “number” from “input’) into the variable mybutton:

var mybutton = document.querySelector(“input”).value

..and one can proceed from there. Why this concept was nowhere explained in clear and concise language in the sites I visited is a mystery to me. I’m finding a lot of the coding documentation on the web is not well-written or clearly explained. It appears that a number of contributors may be proficient at writing code, but less proficient in writing explanatory prose. This can become a problem when researching information.

P.S. A direct, one-line JavaScript capture code does exist:

var guess = prompt(“Input number between 1 and 100”);

where guess captures the data entered into a pop-up box on the web page which is labeled “Input number between 1 and 100.” However, most users prefer to avoid a pop-up box, and there are other disadvantages as well. It will get the job done, but may not be the most efficient way to gather information on a web page.

API Examples

An API is a database kept by an entity which allows developers (programmers) to access its data through a particular protocol. Programmers can get a key that allows them entry into the API; they can then gather the data and display it.

Here are 3 APIs that I found:

1. The NASA API at https://api.nasa.gov/

The NASA API gives access to items such as the Astronomy Picture of the Day, Mars, and Earth pictures. There’s an API access endpoint, documentation, and a getting started guide. There’s an hourly limit of 1000 requests per hour. An API key is recommended but not required (no authentication needed). GitHub has 169 results on a NASA API search.

2. The Goodreads API at: http://www.goodreads.com/api

This API grants access to a lot of information about authors, book reviews, etc. There seems to be less information about single titles, but one can get lists of books as well as entire virtual bookshelf. One can acquire a developer key and there are instructions as to how to how to use the API. The site also has links to a developer’s forum. GitHub shows 95 results for the Goodreads API.

3. The United States Census Bureau API: http://www.census.gov/data/developers/data-sets.html

This site lists about a dozen categories of survey data. In each category, there’s a summary file and data file with sample calls. Users can get an API key. There’s an API forum and technical documentation. GitHub shows 125 results for the census API.

For more APIs, there’s a directory at: http://www.programmableweb.com/apis/directory

Reflections on the Fourth Week at The Iron Yard

This week we learned more techniques for using JavaScript code to place items onto a web page. The code we reviewed to do this seemed somewhat complicated, so I “diagrammed” the code and went over it with Jim (our instructor) to make sure that I understood the functionality correctly.

The class format on weekdays (Monday-Thursday) generally has a lecture in the morning, and lab (working on programming tasks) in the afternoon. Friday is entirely dedicated to the lab work. I’ve started to notice that I tend to reach an impasse about 2 pm, when I think to myself, “what the heck does all this mean, and am I ever going to be able to understand it?” Fortunately, Jim is available to answer my questions and point out what steps I can take next, at which time I’m able to continue with the assignment.

This is the main reason I prefer a classroom learning experience to an online learning experience. The lectures allow me to ask questions at the time the time the material is presented; later, in-person advice and guidance is equally valuable to me when I’m in the midst of processing new information.

This week the data we used with JavaScript came from an API (application programming interface). The particular one we used was the Marvel interface at developer.marvel.com. An API is a database kept by an entity which allows developers (programmers) to access its data through a particular protocol. Programmers can get a key that allows them entry into the API; they can then gather the data and display it. In this case, the results can be visually spectacular with the large number of superhero and comic art available that Marvel offers to developers to use.

I’ve checked out other APIs (and browsed through a directory of APIs to see what’s out there), and I’m highly motivated to get to know how to use them, because there are a lot of exciting APIs out there, and I’m eager to try them out.

Running the code

When I was learning computer programming, before the internet, we learned that there were a couple of main ways to run the computer code: first in, first out, where the first instruction to the computer is the first one completed, and last in, first out, where the latest instruction to the computer is the one that is run first.

Now computer code is run with browsers (e.g. Chrome, Firefox), which makes things a little more complicated. The set of instructions are still put on a virtual “stack,” and in JavaScript, instructions are run one at a time. This is fine if the instructions are simple ones, such as console.log (which simply prints to the console). However, if the instructions are complicated and take a long time to run, this can hold up the rest of the code. Meanwhile, the browser is waiting for JavaScript instructions to complete so it can refresh the screen (at a preferred rate of 60 frames per second).

There’s a way to make things run faster. The browser has its own stack/storage for instructions called webapi, and there’s a secondary storage area called the task/callback queue. A programmer can help out by placing a function (or subroutine) within an instruction called setTimeout, which says wait a certain number of milliseconds (at minimum, it can take longer) before running this instruction. In addition, if a programmer knows that something will take a while, the code can be placed within a setTimeout of zero, which means essentially to hold the code until the stack is clear (and then run it).

The structure, then, is this: there’s a stack running the code (instructions). There’s a browser stack called webapi which holds code that is to be run later. There is another intermediate holding area called the task/callback queue. The stack is taking code and running it. The webapi holds code for a certain amount of time, and then places that code into the callback queue. A mechanism called the event loop checks the stack, and if the stack is empty, it places the item in the callback queue into the stack so that it can be run. (Items can also be placed in the callback queue directly for holding until the stack is empty.)

Essentially, we have webapi – – > callback queue – – > event loop – – >stack.

The goal of the programmer is not to “block the event loop” with code that takes a (relatively) long time to run, but to allow the faster instructions to go into the stack, and the more complex instructions to go into the callback queue or webapi to wait and run when the stack is clear.

This produces a web page which loads and responds quickly.

Reflections on the Third Week at The Iron Yard

We continued to learn JavaScript in week 3, focusing on functionality and constructing our own libraries of functions. We also got an introduction on how to place JavaScript on a web page so that the results of the code show up. There was also some review on html and css; I was particularly interested in constructing buttons. On Friday, we had an exercise in which we set up a web page using html and css (which we hadn’t used significantly since week one) from a diagram. The web page I made was less sophisticated than I had hoped for, but this is something I can work on in the coming weeks.

I got another chance to present my code to the class for discussion. We also worked on some team projects, and I’ve been impressed with the results from collaboration.

We were introduced to prototypes in JavaScript, which didn’t make sense to me until Jim went over one of the exercises, and I realized that prototypes are a way to associate a function with an object. It’s generally easier and more effective for me to understand an aspect of code when it is put into practice, beyond just reading about it.

I anticipate even more progress in the upcoming weeks.

Reflections on the second week at The Iron Yard

During week 2 we worked on JavaScript. I was glad that I went through the JavaScript exercises at Codecademy before class started, because we quickly went through the basics and into the more complex aspects of the programming language. If I had not already had experience with those basics, I might have felt lost.

We continued to read each other’s code, which was useful in that we were able to see that, in general, there are different ways for the code to accomplish the same task. Sometimes we paired up to compare methods; other times someone would get up in front of the class to show the code they had written and invite comments. I was able to do this earlier in the week.

On Friday, some of our assigned tasks involved using one function to call another. A particularly complicated assignment required us to write a function where one of the arguments was another function (referred to as a callback). This initially posed a dilemma for me, since I could not see how this could work unless I was able to add functionally within the callback—and, as it turned out, that’s what needed to be done and was actually possible, though not easy.

Along with this we covered “best practices” of coding, as well as the reasons why one style of coding might result in fewer problems than another style. In addition, we continued to learn more programming tools and techniques.

Overall, this continues to be a satisfying learning experience. It is intensive, but the intensity seems to give the tasks focus. Looking forward to seeing what’s next!