Resurrected news articlesWritten by Richard Heyes, on 15th August 2020
Here are some old news articles that I originally wrote some time ago. For whatever reason, they were removed from the site but the information in them is still valid so I've decided to resurrect them.
Read all about dotted and dashed lines here
This is an article that I originally wrote in 2013 and is all about the then-new dotted and dashed lines feature of the
canvas tag. It's possible to create dotted and dashed lines even without
this setting but it's very clunky and curved lines aren't possible. So native dotted and
dashed lines are definitely the way to go if you have the choice.
Read about drag and drop between two canvas tags here
This article is also from 2013 and is an example of creating drag and drop between two
tags. Normally you might think that dragging between
canvas tags isn't possible but it is if
you add a bit of
How to measure the text height with the canvas tag
Also from 2013 is this article about measuring text height when you're working with
When you use the
measureText function you aren't given the text height - however,
this article details a method that will allow you to get both the width and the height of
The new features of the canvas v5 specification
Back in 2012, this was an article about the then-new features of the
canvas v5 specification.
Such new features include things like a new
and more. Now, 8 years on, a lot of the features still haven't been implemented (some have
Path object, for example, would be very useful but still hasn't
been implemented - however, RGraph has an alternative that can be used
which is detailed here.
A description of Path2D objects
From early 2014 this article goes into the then-new
Path2d object that had been
added to the
canvas v5 specification. It details the
API and gives you examples of its use.
RGraph has its own pathing function which turns paths into a single string (like
So you will see things similar to this in the RGraph codebase:
this.path( 'lw % b m % % l % % s %', linewidth, x, y, width, height, color );
You don't always have to use semi-colons at the end of lines in
can lead to better-minified code. This article explains why.