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Daniel Deng
Courses Plus Student 4,322 PointsgetContext()
I have asked this question to Andrew--the JQuery instructor. If I get his answer, I will post it here.
In the JQuery's simple drawing app, this line of code: var context = $canvas.getContext("2d"); always complaints that getContext is not defined.
Even I used jquery 2.1.1., the problem still exists. If I comment out this line of code, then it compiles.
Any idea?
2 Answers
Jason Anello
Courses Plus Student 94,610 PointsHi Daniel,
$canvas is a jQuery object, not the actual canvas element. Accessing the 1st element (index 0) of this jQuery object will get you the canvas element
$canvas[0]
I'm not sure if this was omitted from the video but it seems to be in the downloadable project files.
var context = $canvas[0].getContext("2d");
Daniel Deng
Courses Plus Student 4,322 PointsThat's why. Thanks for your clear explanation.
Jason Anello
Courses Plus Student 94,610 PointsYou're welcome.
Daniel Deng
Courses Plus Student 4,322 PointsDaniel Deng
Courses Plus Student 4,322 Points(from Andrew) If you do $canvas[0] rather than $canvas that should do it. :) [0] grabs he plain old JavaScript representation of the canvas so you can draw context.