The next step after learning javaScript is to start creating some actual projects, or at least some examples of basic features and modules. For todays new javaScript example post I thought I should write a quick post on having a long once method that often proves to be an important part of a basic debugging kit of sorts.

Learning to use the console.log method to log something to the javaScript console of a browser, or the standard output of a terminal in a nodejs environment is one of the first things to become aware of when learning javaScript for the first time. However just having console.logs all over ones source code is not always the best way to go about debugging code, often it might be better to have a custom log method that is used in place of doing something such as that. That is having a log function all over the source code of a project, and having everything pipe to this function first. Then in the body of that function I can use console.log to log out some kind of debug message, or I can comment that out with just one line. I can also have this kind of messaging piped to something other than console.log.

Anyway I also often find myself in situations in which if something happens I just want something to be logged once, not over and over again for each element in a loop. To create such a log function I would need to have a function that will return this kind of function, in other words a javaScript function closure.

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When working out what a path should be for some expressj middleware it is possible to make use of some parameters for paths. These parameters are a way to make it so that a part of a path is a kind of parameter, the value of which can then in turn be obtained in a request object property called req.params.

For example say that you have a folder that contains a whole collection of project folders. With that said lets say you want to create an express script where there will be an examples path, and then there can be a folder name that will correspond with s folder name in this examples folder. In each example folder there is a file that I would like to send for the project folder when that path is requested. One way to go about doing so would be to make use of these path parameters.

So then in todays express post I will be going over just a few quick, simple, examples of path parameters.

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I would like to make at least a few simple express.js examples just for the sake of making a few actual projects with the framework. There is learning the basics of working with express, or any framework for that matter, but sooner or later I have to make a few actual projects with it or move on to something else.

This express.js example aims to just be a simple little projects that is not intended to be used in production, but just a simple silly little thing to have up and running on a local network for a little while. The idea here is to make use of nodejs, express, ejs, and express session, to just have a simple little canvas powered client system with little pointer circles in it. Each circle in the canvas is a client currently connected to the server on the local network.

I am going to be keeping this example simple in the sense that I am not going to be doing anything fancy with authentication, making use of a database and so forth. When it comes to session storage I am just going to be using the default memory store. However I think that doing so is okay sense I intend for this to just be a simple little thing that will only have a few computers connected to it at any given time, and it is just going to be a simple little think where there is just serves as a crude starting point for something that will end up getting very complicated when it comes to making this into some kind of real project.

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When working out a simple expressjs project for the first time there is starting out with some very basic hello world type examples that involve just a single middleware function attached for a single path of a project. When doing so there is a request object and response object that are both given as arguments for the middleware function. These two objects are useful for working with an http request, as well as creating and sending a response for that request. However there is another typical parameter for these functions that is the express next middleware parameter. This parameter of a middleware function is a function that can be called to allow for express to continue to the next middleware function to be called. The next middileware function can be the next function in an array of functions rather than just a single function, however in other cases it can result in continuing to a whole other path pattern in the main app.js file also.

So then in this post I will be going over a few simple examples of the next argument that is used in middleware design for expressjs projects. In the process of doing so I will also be touching base on a whole bunch of other expressjs, and nodejs related topics.

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As of expressjs 4.17.x there is now an express text built in middleware function, that is one of a few built in middleware functions based off of body parser, which is also a built in middleware for parsing incoming http post request bodies. Using the body parser middleware directly might still be the best way to gain the highest degree of control over parsing incoming post request payloads, but there are a number of built in methods now for json, raw data, and plain text.

There is going over every little detail about the body parser middleware, but if I just want to parse text then there is the express text middleware. Using the function helps to keep the rest of my code a little more clean and readabule compared to suing the body parser directly.

So then in this post I will be going over soem basics of the express text middleware, and in the process of doing so I will also be touching on a wide range of other topics when it comes to parsing incoming post requests. In these examples I will be sticking to just using nodejs and express, and as such I will be using XMLHttpRequest as an http client in a single html file as a way to go about creating post requests. I will also be suing the express static built in middleware as a way to go about hosting the simple yet effective client systems for these examples.

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