[solved] Characters < and > not correctly displayed by sketchpad

jjstekelenburg

Hi,

There is some strange bug in OS 0.27.3 that was not there in 0.26.
In a flanker task I present this kind of stimuli: >>>>>, >><>> etc. by using the text tool of the sketch pad.
However, the output to the screen is totally different >>>>, >>>><>. So OS messes up my stimuli.
I guess in the latest version of OS it cannot handle characters < and > anymore?

Jeroen

sebastiaan

Hi Jeroen,

It sounds like OpenSesame tries to interpret these characters as part of HTML tags. As of 0.27, a subset of HTML tags can be used to add text formatting, as described here:

• http://osdoc.cogsci.nl/usage/text-formatting/

However, the specific examples that you give are displayed fine for me. Presumably, the problem occurs with strings that are syntactically (but unintentionally) valid HTML. Do you have an example script? Or example strings that trigger the problem?

Right now, you cannot disable HTML parsing in the sketchpad, although you can do so in inline_scripts, using the html keyword:

from openexp.canvas import canvas
my_canvas = canvas(exp)
my_canvas.text('Do not make <b>this</b> bold', html=False)
my_canvas.show()

Cheers!
Sebastiaan

sebastiaan

Hi Jeroen,

I looked at the experiment, and the <> characters are indeed interpreted as HTML tags. What makes things a bit unpredictable is that there are carry-over effects from one string to the next (issue).

The obvious solution is simply to replace the sketchpad by an inline_script:

from openexp.canvas import canvas
my_canvas = canvas(exp)
my_canvas.text(self.get('Stimulus'), html=False)
my_canvas.show()

If you think this complicates things to much for students (is it part of a course?) then another workaround would be to use {} or [] characters in the sketchpad.

Hope this helps!
Sebastiaan

jjstekelenburg

Hi Sebastiaan,

It is the final experiment the students have to program in the course. Since it is a first year course, we do not want them to do any scripting.
Meanwhile there may be a work around, inserting a space in front and at the back of the stimulus prevents the unpredictable effects and the stimulus is now presented correctly.
So for now that will be our solution.

Jeroen