This course introduces students to the fundamental concepts and techniques of web development and computer programming through web mapping. Students will become familiar with current web standards and proficient in manipulating the structural, stylistic and behavioral elements of web maps through programming. Students will translate these practices to achieve objectives in web cartography such as the display of a basemap, the thematic representation of data, and the employment of interaction to enhance visual communication and the presentation of information.
After completing this course, the student will be able to:
This lesson will provide you with an introduction to the foundational technology stack used in web map development. We will introduce you to 3 separate coding technologies (HTML, CSS, and JavaScript), which work together to produce a web page and map application. The module suggests that web map design is achieved using these three technologies to structure content (HTML), and give form (CSS) and behavior (JavaScript) to this content. Design is then the convergence of content, form, and behavior.
Additionally, we’ll practice writing these technologies within our powerful text editor, Brackets, as well as using in browser development tools to inspect the Document Object Module (DOM) and debug our code.
In the previous module learned how to use HTML tags to structure our content within a webpage, and how to apply CSS style rules to modify the form of this content, or how that content looks (e.g., color, size, etc). These two elements, content and form, and the relationship between them, constitute two fundamental aspects of traditional design. Within the web environment we are able to introduce a third aspect to this classic understanding of design: that of behavior, which helps promote user interaction. In web mapping and web development in general today, the behavior of a web page or entities within it are controlled by the programming language JavaScript.
This module begins developing a foundation in computer programming using JavaScript. While we will quickly apply these practices to web mapping, you first need to gain an understanding of the basics of JavaScript, which can be largely applied to web development in general. If you already know a programming language, then you may find these easy to pick up, though you’ll gain from learning the specific syntax with which we write JavaScript, as well as its nuances. If JavaScript is your first programming language, you’ll be pleased to know that these programming fundamentals are not unique to JavaScript, but can be applied to the other programming languages as well.
In the previous module, when we ran our script within our web browser (such as by hitting page refresh), our JavaScript executed from the top of the script to the bottom. This is to say, the “flow of program execution” moved in one direction, from top to bottom. However, often we want to interrupt this flow of execution in various ways. This is where the idea of control structures come into play. Within this lesson, we’ll learn how we control of flow of our JavaScript program.
Often when we’re programming, there are certain chucks of code (groups of JavaScript statements) that are all related and work together to accomplish specific functionality within the overall program. And often, we want to execute these at specific times, than once, or even repeatedly. Within this lesson, we’ll learn how we make our programs more efficient through the use of functions. We’ll first learn how we declare and define functions. Then we’ll make functions more powerful by passing information to them and receiving information in return.
This lesson introduces you to another JavaScript data structure (a data type used for storing accessing, and updating various values): the JavaScript Object. You’ll learn how to create these, populate them with key/value pairs, access these values, and update the object with new properties. We’ll also learn how to loop through objects, as well as how objects make use of a special kind of function known as a method.
This lesson will begin to get us acquainted with the Leaflet JavaScript mapping library. We’ll learn how to read and understand the Leaflet API Reference documentation, which tells us how to access and use all the awesome Leaflet JavaScript functionality. We’ll then work on creating a basic Leaflet map, including:
Most importantly, we’ll want to learn how Leaflet employs Scalable Vector Graphics (SVG) to draw representations of geographic features on a map.
Within this lesson we sharpen our understanding of the GeoJSON specification and how data are encoded within it. We will use a useful web tool at http://geojson.io/ to create and display GeoJSON data, and then we’ll use this GeoJSON-encoded data within Leaflet to draw new data layers. To better understand how to use GeoJSON in Leaflet, we go into more depth exploring the Leaflet options and methods available to a Leaflet GeoJson layer.
This week’s lab will offer you a guided tutorial on storing GeoJSON data in an external file, loading it into the script, and representing those data thematically with Leaflet.
This lesson continues our study of creating and using the Leaflet L.GeoJson object. Beyond the powerful options available when we create layers using this method (pointToLayer, filter, oneEachFeature), we’re going to invoke Leaflet methods on layer groups and individual layers after creation. We’ll create additional layers in support of making a bi-variate promotional symbol map. We’ll also learn how to use a Leaflet layer control to manage multiple data layers, and practice setting universal styles and layer-specific styles using the L.GeoJson style option. We’ll finish up by introducing some advanced techniques for code refactoring.
This lesson will instruct you how to create a dynamically generated choropleth map in Leaflet with an accompanying legend. It also explains how to use the jQuery JavaScript library to load an external data file using AJAX.
As in MAP 671, let your creativity soar to new heights with a project of your choice. You will create an public, interactive mapping project in a new repository with a theme of your choice. Requirements will be detailed when the module is released.