Over the weekend, I have started working on my CS-343 final project by creating a simple Angular application that I will use as a base to build the rest of the project off of. The application simply draws a rectangle with a length and width that are entered by the user. When the user enters a new width or height, they can click a button to update the rectangle without reloading the page or loading a new page. The application currently looks like this:

Although this application is extremely basic, writing it has greatly improved my understanding of TypeScript, CSS, and especially HTML. While the in-class activity on Angular helped introduce me to the basics of HTML, researching and working with HTML on my own has definitely made me more comfortable with it.

I started writing this program by creating elements to take user inputs with text fields and buttons, using the class activity as a reference. I researched the HTML tags I needed to create these elements, and I came across a site called w3schools.com that provides documentation of HTML tags (such as <form>) as well as executable example code to demonstrate their uses. This site proved to be a valuable resource for understanding HTML, and I will certainly continue to refer back to it as I continue work on my project. Once my input forms were created, I quickly discovered that submitting data in a form refreshes the page by default, which I did not want to happen. I found out through research that writing ‘onsubmit=”return false”’ in the <form> declaration overwrites this behavior, and I quickly added it to my forms.

Next, I researched how to draw a simple rectangle that I would resize according to the input. I found that I could create one using the <div> tag and specifying its dimensions in its style field. I also discovered that I could change these dimensions code by setting an id for the <div> and using the ‘document.getElementById’ function to edit it from the TypeScript code, allowing me to pass data from my input fields to my rectangle

At this point, I could successfully resize the rectangle using user input. However, the ‘Text’ label was not centered in the rectangle, and I decided I would try to fix that. I came across another page from w3schools that explained how to center text both horizontally and vertically using CSS. I decided I would make the rectangle into its own Angular component so that I could put all the necessary style information into a .css file, and I managed to figure out how to do this by referring back to the class activity.

So far, this project has taught me more about HTML, CSS, and Angular components. It has also led me to several helpful references, such as w3schools.com, which I am sure will help me going forward. Now that I am feeling more comfortable with HTML and Angular, I plan to work on creating more elements that take user input and organizing my components into a more interesting layout similar to my wireframe. I am really starting to enjoy working with HTML and TypeScript, so I am looking forward to making more progress on this project in the coming week.

From the blog CS@Worcester – Computer Science with Kyle Q by kylequad and used with permission of the author. All other rights reserved by the author.

With the semester coming to an end and the holidays, I’ve been busy and have not made as much progress as I would have liked on my SPA. I did find a better way of obtaining the evolution chains. The looped API calls were a sloppy solution, but I realized I could simply make multiple calls per input. After that I tried to find a way to visually organize the evolution families, but my nested Angular loops make it difficult to style and I haven’t found a satisfactory solution yet.

I have implemented the popup that displays the entire evolution family. The popup blocks interaction with the underlay and forces focus on the popup until dismissed.

A general issue I have ran into is the SPA updating as it fetches data. This causes the images to load at different times, affecting layout. I also have an issue where the page does not always grab the evolution family causing it to occasionally pass a null evolution chain. Searching a second time often fixes this but I am not sure of its cause.

My goals for this project now are to polish up what I have and find some new useful functions to add.

From the blog CS@Worcester – D’s Comp Sci Blog by dlivengood and used with permission of the author. All other rights reserved by the author.

Before creating a database, I needed a way to associate files with a user. This requires user authentication, which is thankfully provided by Google Firebase. In my experience, 3rd Normal Form (3NF) is the best compromise in database normalization, so I strive to achieve this when creating one. Therefore, instead of blindly implementing file storage for a single user, I put some thought in ahead of time of how I would store the data. Currently there are not many data to store, but 3NF is helpful in allowing for additions to a database in the future.

Google’s authentication provides a familiar, smooth interface for users to login or create a new account. In properly-designed, object-oriented software, it is a quick and secure way to implement authentication to quickly launch a product and still easily replace it with your own authentication implementation in the future. The API took a little getting used to (and again, their documentation is not easily converted to Typescript), but it only took a few hiccups to get everything working reliably.

The biggest of the hiccups was “this.”, (pronounced “this-dot”) when referring to member variables. I’ve heard legends of the horror of “this.” in JavaScript. I’ve seen Twitter posts lamenting the language for its strange behavior. But I never expected this.

In typical Java fashion, I was using callbacks for the authentication service. The module would need to update member variables, which are bound to elements through the *ng-if directive. Coming from Java, I naturally assumed calling “this.variable” within the callback would change the value, and the console was printing the correct value, but only within the callback function. As soon as it finished, “this.variable” was the old value. As it turned out, I was referring to two different “this’s”.

The problem is that “this” refers to the context in which a variable is called, not the class in which it is defined. This Stack Overflow post has some good answers describing why and the proper way to use it. My solution was to use arrow functions to pass the correct context to the callback function when I subscribed to it, like so:

ngOnInit() {
    this.angularFireAuth.authState.subscribe((user) => {
        this.firebaseAuthChangeListener(user, this);
    });
}

Subscribing to the authState gives us a user object, which needs to be passed to the custom callback function. ngOnInit() is called to initialize the Component, so the context is the Component itself. Therefore, we can refer to it using “this”, which we do to refer to other services and methods. Modifying the callback function to also take the context means we can modify the member variables of the Component using this argument.

I tried a few other solutions, but this was the simplest and the only one that reliably worked. If there are better TypeScript solutions, I’d love to hear them. For now, I can reliably register users and use their unique IDs to associate them with their file uploads in the database.

From the blog CS@Worcester – Inquiries and Queries by ausausdauer and used with permission of the author. All other rights reserved by the author.

For my final project in CS 343, I have chosen to create a
Pokédex SPA that uses a public database, PokeAPI, with RESTful API. So, my
focus has been on page layout and how to search for data with limited methods
since the backend is all set.

I went through several different ways of trying to set up
the page layout, but eventually I settled on CSS grids. I found these grids to
be intuitive and easy to manipulate. It was not long until I was able to
successfully create a basic layout to work with. I used the grid-template-areas
CSS property to set a dynamically resizable layout.

CSS:       grid-template-areas:
     “header header”
                                                                “menu content”
                                                                “footer
footer”

I used the CSS fractional units to determine the width of
the columns (1:4) and static sizes for the height of the header and footer with
the content in-between filling the page. Now that I have a basic layout to work
with, I can focus on added functionality.

A function I have currently implemented is a search for Pokémon
by id number or name. For now, the page simply displays the name, image, and id,
but the API provides much more data that I haven’t included. The evolution tree
function is still a WIP. Connecting the evolution chains to the specified Pokémon
was a small issue. The API does not provide a way for an evolution chain to be
searched for by Pokémon. I eventually settled on creating a map, at page load, by
looping through all available chains and pairing them with their respected Pokémon.
The plan is to use the chain to render a pop-up that displays the entire evolutionary
tree. I also have a moves search that works similarly to the Pokémon search.

I am now trying to think of ways of using the pokeAPI in interesting ways. I will probably add some more search options to the menu as well as adding more options for linking relevant data. Even though my project is still fairly new, I have learned a great deal about HTML and CSS so far.

From the blog CS@Worcester – D’s Comp Sci Blog by dlivengood and used with permission of the author. All other rights reserved by the author.

I have have been working on a big term project lately for my all classes. I when me and my group were planning what to do I decided to try use a UML to do the planning like I had learned about in my class a few months ago. It was big help in figuring about how to structure the program and figure out how make it work. It also help a lot with being able to communicate with group members so we could all work on it at same and it would still be compatible.

From the blog CS@Worcester – Tim’s Blog by therbsty and used with permission of the author. All other rights reserved by the author.

As there are now just a few weeks left in the semester, it
is time to start working on my final project for CS-343. This project is to
develop a Single Page Application in TypeScript using the Angular framework,
which we have been learning in class over the past month. From now until the
end of the semester, I will be making weekly posts documenting my progress with
this project and what I learn while working on it.

My final project began with a proposal, for which I was to
create a conceptual design for a Single Page Application using a wireframe. This
helped teach me how to design a layout for an application’s components before
programming it. My idea was to design a layout for a customizable puzzle game. When
it comes to software development, my main interest is in making games. For this
reason, I thought that using this project to make a basic game while also
learning about creating Single Page Applications in TypeScript would be
something I’d enjoy.

My current concept involves some kind of grid-based puzzle game,
such as minesweeper. The user would be able to interact with a variety of components
in an options menu to change the size of the grid as well as other aspects of
the game, like the difficulty and time limit. Changes made to these options
would update the main play area in real time without the need to reload the
page. I also included a help menu that would contain instructions and potentially
a hint button for extra interactivity in my proposal.

I drew my wireframe layout for this application concept on
paper. You can take a look at it right here:

I still am not certain that this is the idea I want to go
with for my project. I think it is a rather simple idea due to its lack of
communication with a back-end server. I also have yet to decide on the details
about the puzzle game itself, and I don’t know if such a game is even possible
to make with angular components. I will have to do more research about Angular
and TypeScript to help solidify my plan. Despite my doubts, I am looking forward
to learning more about writing applications in TypeScript, and I will definitely
get development started during Thanksgiving break.

From the blog CS@Worcester – Computer Science with Kyle Q by kylequad and used with permission of the author. All other rights reserved by the author.

After completing the file upload portion of the project last week, I found myself in fear of committing my changes. I have always had this problem: I want each commit to be concise, change as little as possible, and even have perfect whitespace. This minimizes changes and makes it easier to track down commits where bugs are introduced, but moving forward like this will slow me down, as it has in the past.

But once I made that first commit, things starting progressing quicker. It was time to start adding more Components. Once I could interact with the files I was uploading, it was time to be able to delete files. With more functionality and interaction with the cloud storage, it was best to remove this behavior from the Components and move them to a Service. This custom service class handles all interaction with the cloud storage service, so there aren’t some components adding files and others deleting files. Everything is nicely encapsulated, and user interaction only needs to forward actions to the Service.

I do wonder if there are downsides to this design, and whether Angular might have features I’m missing that may be better suited. However, I definitely believe that UI Components in any framework should delegate user interaction to another class that contains the logic. Even so, is importing a Service class the proper avenue? I have also considered passing commands in each Component up to the main app Component, which would have a single reference to the custom Service I created. This would quickly complicate the application architecture, however, because changes in the cloud storage will require updates in the children Components. For example, the list of Files will have to update, and a file shouldn’t be removed from the UI unless the delete action is successful, requiring a callback to be passed down to children.

The software engineering practices I’ve studied and written about this past semester are at the front of my mind. My current solution is rather simple, and although I am anticipating possible problems, I am not over-engineering and adding unnecessary complexity. I am following Clean Code principles from Robert C. Martin; making code easy it read, making it work, and refactoring when necessary.

The overall design of my final project is beginning to solidify. I naively thought I would download all file metadata from the cloud storage when loading the web page and then maintain them from there, but I’ve realized that all of this data is going to have to be stored in another database, which I will access using a REST API. This will store all the file data and URLs to the files themselves and will be a good chance to practice with data synchronization between databases.

Through the next week I will implement the database. Once I have this synced client-side, I can add Components to search/filter the files and load the files that are selected by the user.

From the blog CS@Worcester – Inquiries and Queries by ausausdauer and used with permission of the author. All other rights reserved by the author.

I will be completing a final project for my CS-343 class. I plan to implement a workout planner using angular and webstorm. The general idea of the website will start with the homepage. On the home page there will be any workout that the user has created. Here it will show the workout types, how many reps/sets and what each workout is. Along the side bar there will be a list of muscle groups. The user will be able to click on these side bars to display a list of different exercises that they could choose from. When the user clicks on an exercise, the tab will open up to a display a picture or video of the workout. From here the user will also be able to set their reps and sets count in which they want to add to the workout. To get started on this process I will be designing each of the slides for each workout. Once these slides are created, I will host them together in a folder. These will then be able to be used and manipulated by implementing a new component called workouts. This will contain and html file for designing the basic template of the slides and their layout. The next will be a css file. This file will allow for me to implement more stylistic changes to the pages. The last two components in the workout section will be .spec and a typescript file. The typescript file is where all the code that will allow for the user to manipulate and change pages. This will also include the code which will allow for the user to take add their reps and sets to the workout. For the first week I have been working putting together each of the slides that will be used for the site.

The tentative plan for these slides will be to make them
images and incorporate the other elements on top of the image. Each image will
have a unique ID which will allow for the code to distinguish what workout the
user is currently looking at. Once this large section has been completed, I
plan on moving onto the homepage design where the workout will be displayed. On
the homepage the user will be able to remove workouts that they no longer want
or remove their whole workout plan entirely and start from scratch. Due to the
set up of the app, the workouts will not save once disconnected because that
would require saving the data somewhere, while the app is offline.

From the blog CS@Worcester – Journey Through Technology by krothermich and used with permission of the author. All other rights reserved by the author.