Intro to creating web apps with swmmReact

Creating web apps with swmmReact is simple. Developing environmental models and showing them off is easy with swmmReact. You can have people open your files, work with current versions, read results, focus on what you want them to focus on, add maps, and make responsive, interactive systems. swmmReact can help people feel engaged with your data, showing models and model results that abstract away finer details and improve communication.

About this example

This particular example is made for those that are very new to web programming. By the time you have completed this example, you will have a working web page that you can display the results of a running model on your own computer. You can then upload those files to a web server, or simply make a web page on Github and move on from there.

Setting up your computer for development

You won't need to do a lot of work to start programming with swmmReact. While you'll be working with Node.js, npm, React, and Github desktop, there's really only 2 programs that you will install in this example: Node.js and Github desktop. Of course I'll walk you through each one:

Node.js

Node.js® (https://nodejs.org/en/) is an open-source, cross-platform JavaScript runtime environment. Javascript has often been associated with programming for web browsers, but Node.js allows you to do all kinds of cool desktop and server-side programming that used to belong squarely in the domain of php, python, perl, and plenty of programming paradigms that probably aren't prepended with 'P'. JavaScript different because it starts with a 'J'. Check out some of the other details here: (https://nodejs.org/en/about/).

Download and install Node.js here: https://nodejs.org/en/

Github Desktop

Github Desktop (https://desktop.github.com/) isn't the only way or the best way to interact with Github, but it is a colorful GUI with plenty of fun buttons to push, and that's what's really important. You'll need to sign up for a Github account (https://github.com/) but they make the process as painless as possible.

Download and install Github Desktop here: https://desktop.github.com/

npm

npm (https://www.npmjs.com/) stands for Node Package Manager, and believe it or not, you already installed it. To make sure I'm not lying to you, open up a command prompt (search cmd in your desktop's search widget) and type

npm -v 

That will give you the version number of your current npm install. One last thing: their website will ask you to create an account or subscribe to the pro version. If you're into that sort of thing, don't let me stop you, but you really don't need to.

React

React (https://reactjs.org/) is an amazingly easy and fun programming system based upon JavaScript. React allows you to create websites incredibly quickly, and really one of the best ways to get acquainted with it is 'create-react-app'. Once you are done with this tutorial, it would be a good idea to check out how easy it is to use create-react-app to make simple (or complex) web apps.

Copying and running the demo

Once you have have finished your installs, use Github Desktop to make a copy of these files by selecting from the top menu: File->Clone Repository. A window should pop up and you can select 'URL', and enter

https://github.com/swmm-js/b20-editor-interface.git

inside of the text box. Keep note of or change the 'Local Path' text box, and then click 'Clone'. This will download the files to your computer.

Open up a File Explorer window and find the folder where you've copied these files.

To test that everything works, open up a command prompt. Navigate to the folder where you've copied the files by typing something like the following:

cd C:\Path\to\files\you\downloaded\b20-editor-interface

and then type:

npm install

This should get all of the depencencies for the program, which shouldn't take long. Once the install is finished, you should be ready to run the demo. Run the demo by typing:

npm start

After a few moments, your web browser will probably pop up and display the swmmReact UI. If your web browser doesn't open automatically, open one yourself and navigate to

http://localhost:3000/

in the address bar.

Modifying the demo

You can modify the demo to show off your own files. Keep in mind you are running in a web browser, so files with output greater than 4GB, and files that take a long time to run are not appropriate for this demo. You can learn later how to use swmmReact, swmmNode, and swmmLink to work with large or long-running files by sending your work to a server and having it notify you when your results are available. You can also pre-load your results within your website and allow swmmReact to work with the data without ever needing to run swmmReact's processing capabilities.

Building the files to run on your own web server

To build a set of files that you can run on your own web server, use the command window again and type:

npm run build

This will create a set of files that you can find in the following folder:

b20-editor-interface\build\

You can copy these files to a web server, or push your files to Github by opening Github Desktop and selecting 'Commit to Master' in the bottom left hand corner. The process for using Github to serve your swmmReact website is explained in excellent detail here: (https://github.com/gitname/react-gh-pages)

Structure of the traditional swmmReact UI

For editing, the swmmReact interface utilizes a large number of dialogs and forms. In general, the pattern for a dialog is:

• DialogInitiator: An element or event like a button click that calls the dialog.

• DialogWrapper: A set of common elements that a certain type of dialog will have. This can include styles, drag and drop/resize controls, 'Close' buttons, and ID editors.

• Dialog:

  • Separates the data that is to be edited from the primary data of the program. Separating the editing data allows for undo type operations without modifying the base data.
  • If the program is set to 'instant-run', the dialog can also protect the 'instant-run' effect by requiring a 'Save Edits' button to be clicked before the system calls 'instant-run'.
  • Some dialogs (e.g. node and link dialogs) modify several tables at once.
  • Dialogs can create new records with default values.

• Form: This is the editor for a specific dialog interface. The user can modify the data for parts of a model using the form controls. Some dialogs will modify several tables at once,

Conclusion

Now that you have a basic idea of how to utilize the swmmReact UI, you can move on to some of the demos for displaying results, modifying files, running simulations, and setting up and logging in to file processing servers. Thanks so much for taking the time to read this, and if you have any questions, you can contact me at [email protected].