6.2 Release Notes

[jodeleeuw]

Note from @jodeleeuw: 6.2 is our first release that is made possible by support from a grant by Mozilla Open Source Support (MOSS). This award has allowed @becky-gilbert to join the team, and she has been essential to all of the work reflected here. So: thanks Mozilla, and thanks @becky-gilbert!

New Features

• The instructions plugin now has a page_label parameter that allows you to change the default "Page" text when showing the page number/total. This provides better support for non-English languages. Thanks @GEJ1! (Instructions plugin changes #1081, instructions plugin can't display 'Page' in another language / show_page_number' does not appear in the documentation #1082)
• By default, the survey-* plugins now turn off the autocomplete/autofill feature, so that participants won't see a list of their previous responses in text entry fields. This feature can be turned back on with the new autocomplete parameter. Thanks @chrisbrickhouse! (Default to autocomplete=off on form plugins, with parameter to turn on #1064, survey-*: stop autocomplete add param to enable #1073)
• The survey-html-form plugin now includes the autofocus parameter that allows you to specify the ID of the form field that you want the page to focus on when the trial loads. Thanks @chrisbrickhouse and @grocio! (survey-html-form: add autofocus parameter #1072, Can't set focus on input for survey-html-form #1062, Disable autocompletion of text forms #669, Disabled autocompletion of text form (issue #669) #671)
• In a survey-likert trial, you can now select a response by clicking on the label text. Thanks @kurokida! (Enable to respond by clicking string directly. #701)
• You can now set a minimum valid keyboard response time in your experiment using the new minimum_valid_rt parameter in jsPsych.init. This is useful for automatically ignoring key presses that are unreasonably fast. Thanks @andytwoods! (Merges minimum valid RT changes into master #1139, minimum_valid_rt #546, In rare cases, extremely fast RTs in RT task #542)
• All audio-*/video-* plugins now include the response_allowed_while_playing parameter. If false, the participant will not be able to respond until the media has finished playing. Before then, keyboard responses will be ignored, and buttons/sliders will be visible but disabled. (Add option to prevent response before media ends in audio-*/video-* plugins #1137, Add response_allowed_while_playing parameter to audio/video plugins - fixes #1137 #1145)
• New canvas-* plugins allow you to use a function to draw the stimulus on a HTML canvas element, and collect a keyboard, button, or slider response. A canvas stimulus can be useful for displaying dynamic, parametrically-defined graphics, and for controlling the positioning of multiple graphical elements (shapes, text, images). Thanks @cjungerius! (Canvas integration plugins #700)
• New maxdiff plugin displays a set of options to be selected as one of two mutually-exclusive categories, typically 'most' or 'least' on some criteria, e.g. importance, preference, similarity. The same option cannot be selected for both categories simultaneously. Thanks @awhug! (Maxdiff Plugin #1136)
• The free-sort plugin now has new parameters to control: sort area shape (square or circle), initial item positioning (inside or outside the sort area), border/background colors indicating when items are in/out of the area, magnification of items while dragging, and text indicating whether and how many items are left to be placed inside. Thanks @pjkohler! (updates to free-sort plugin, new functionality #1018, Updates to free-sort plugin #1203)
• The image-*, animation, and categorize-animation plugins now include a render_on_canvas parameter to fix the problem with brief blank screens (white flashes) between consecutive images/trials in Firefox and Edge. Setting render_on_canvas to true fixes this problem, and setting it to false presents the image(s) in an img element, as before. (Images don't present consecutively in jspsych-animation (for firefox only) #891 Present images conseuctively (no white flash) #969, add render_on_canvas option, fix maintain_aspect_ratio - #891 #969 #1172 #1174)
• New documentation pages in the Overview section on the jsPsych website: Browser and Device Support and Running Experiments.
• New 'safe mode' feature automatically prevents CORS errors when running experiments offline (e.g. by double-clicking the HTML file). This can be overridden with the new override_safe_mode parameter in jsPsych.init. For more info about CORS errors and safe mode, see https://www.jspsych.org/overview/running-experiments/#offline.

Changes

• The *-slider-response plugins now automatically save the stimulus and slider start position in the data, and they return an integer rather than string as the response. Thanks @kupiqu! (systematically saving stimulus and slider start position in all slider plugins #736, image-slider-response doesn't log stimulus #689, Documentation type mismatch for slider response plugins #1058).
• In the *-slider-response plugins, the slider starting value parameter is now called slider_start (for consistency with video-slider-response plugin, where start refers to the video start time). The slider's starting value is now stored in the trial data, which is useful if the researcher is randomizing the slider's starting value. (Inconsistency in *-slider-response parameter names #1060, systematically saving stimulus and slider start position in all slider plugins #736)
• When require_movement is true in the *-slider-response plugins, the user will be allowed to continue after clicking on the cursor (rather than having to move the cursor and release it). This makes the sliders more user-friendly, especially when using a discrete/sparse scale, and when the participant wants to respond with the slider's starting position. Thanks @kupiqu! (Allow for less intrusive slider "require movement" behavior? #696)
• In the same-different-html and same-different-image plugins, the default values for first_stim_duration and second_stim_duration were changed from 1000 ms to null. This fixes a bug that prevented these parameters from being set to null. Thanks @dschreij! (Documentation of (at least) same-different-html appears out of date. #755)
• In all *-button-response plugins, the "button_pressed" data is now saved as an integer rather than a string, which is now consistent with the documentation. Thanks @vijaymarupudi! (Documentation type mismatch for *-button-response-plugins #682)
• By default, the image-*, animation, and categorize-animation plugins now draw the images on a canvas element, to fix a problem with brief blank screens (white flashes) between consecutive images in Firefox and Edge. Setting render_on_canvas to false will present the image(s) in an img element, as in previous versions of these plugins. (Images don't present consecutively in jspsych-animation (for firefox only) #891 Present images conseuctively (no white flash) #969, add render_on_canvas option, fix maintain_aspect_ratio - #891 #969 #1172 #1174)
• In the video-* plugins, the parameter for specifying the video file(s) is now called stimulus rather than sources, for consistency with other plugins. (video-* plugins: stim parameter name change and tests #1261, Fix stimulus parameter naming in video response plugins #1171)

Bug Fixes

• The rdk plugin now appropriately changes the fixation cross color based on the fixation_cross_color parameter. Thanks @cthorey and @lukasshannon! ([FIX] fixation_cross_color in the rdk plugin #643 jspsych-rdk fixation_cross_color not functional #1217)
• Incorrect error message no longer displayed when using jsPsych.randomization.shuffleNoRepeats() (Incorrect warning message in jsPsych.randomization.shuffleNoRepeats #659)
• jsPsych.randomization.repeat() now fails gracefully when the items and repetitions parameters are ambiguous. Thanks @Hrcn ! (Variable name error? #667)
• The start and slider_start parameters now work as expected in the video-slider-response plugin. Thanks @vijaymarupudi! (video-slider-response plugin: start and slider_start parameters not working #713, slider_start and video duplicate id fixes. #714)
• The website's tutorials and the library's example HTML files no longer include the unnecessary closing link tag (</link>) after loading the default CSS file. Thanks @vijaymarupudi! (Removed closing </link> tag #721)
• The labels and radio buttons/checkboxes in survey-multi-choice and survey-multi-select plugins are now properly formatted. Thanks @dillonplunkett! (return checkboxes to within label elements #676)
• We've fixed several documentation errors, such as out-of-date parameter names and broken links. Thanks @akochari, @CarolynBuck-Gengler, @dschreij, @alisdt, and @gorkang! (Update jspsych-same-different-html.md #677, change timing_response to trial_duration in docs #1096, broken links in documentation to plugin data #827, Documentation of (at least) same-different-html appears out of date. #755, Input to submitToTurk must be non-empty #668, Website: Wrong link to data-collected-by-plugins #1225)
• The rdk plugin no longer shows scroll bars on the page. Thanks @wsr017 and @vijaymarupudi! (scroll bars with RDK #881, Scroll Bars with RDK #787)
• jsPsych.addNodeToEndOfTimeline no longer produces an error when the optional callback function is omitted. Thanks @oliveralonzo, @bjmeagher, and @vijaymarupudi! (callback not optional on jsPsych.addNodeToEndOfTimeline function #688, jsPsych.addNodeToEndOfTimeline() bug #918, Fixed undefined type check with typo #690)
• Data collection .first and .last functions now handle the case where the n argument is greater than the total number of trials in the collection, and they throw a descriptive error when n is zero or negative. Thanks @aridyckovsky! (Graceful failure on DataCollection.first and .last #976, data.last(n) should gracefully fail is n > total data size #751)
• The image-button-response and image-keyboard-response plugins now produce a console warning when the trial might be deadlocked because a response does not end the trial (response_ends_trial: false) and no trial duration is set (trial_duration: null). Thanks @chrisbrickhouse and @celstark! (Deadlock possible in image-keyboard-response or image-button-response #1014, Warn about possible deadlock per #1014 #1028)
• Incorrect error message "Uncaught TypeError: Cannot read property 'style' of null at update_loading_progress_bar" no longer displayed when playing HTML5 audio. (bug with audio playing and progress bar #648, Fixes #648 - bug with audio and progress bar #1115)
• Fixed out-of-date Github URLs in package.json file to improve npm install compatibility. Thanks @aridyckovsky! (Update package.json to reflect organization #971)
• Added a more informative error message when the timeline parameter is empty in jsPsych.init() (throw a useful error message when the timeline is empty #853)
• In the case of a timeline with a loop function nested inside a timeline with timeline variables, the timeline variables can now be referenced inside the loop function. (Make nested timeline variables available in loop functions #664)
• The serial-response-time-mouse plugin now works properly when a prompt is added to the screen. Thanks @takat0-ch (Adding prompt to serial-response-time-mouse destroys event listeners #840, can't not use prompt for serial-reaction-time-mouse plugin. #837)
• Fixed a bug where an error was thrown if the Array.prototype had been extended and parameters with COMPLEX types were used in plugins. Thanks @egaudrain! (Inappropriate looping technique throws error when attributing default parameters #989, Patching for issue #989 #990)
• jsPsych.init() will now delay execution until the document is fully loaded (Delay init() execution until the document is ready #948). This fixes an issue where jsPsych would create two sets of <body> tags on the document if none existed in the markup (fix duplicate body tags #316). Thanks @bjoluc!
• Fixed bug on touchscreen-only devices (phones/tablets) that caused the last button that was touched to remain highlighted on successive *-button-response trials. (Investigate button highlight persisting on mobile devices #977)
• The preloading progress bar correctly centers when the experiment_width property is set in jsPsych.init(). (Preloading progress bar not centered when experiment_width property is set in jsPsych.init #1160)
• For all video-* plugins in Firefox, if a non-zero video start time is specified, then the first frame of the video is no longer briefly visible when the trial first loads. (non-zero video start time causes video to jump in Firefox #712, Fix FF video issue with non-zero start time - fixes #712 #1162)
• Fixed alignment problems between slider positions and labels in all *-slider-response plugins. (fix slider label positioning with custom CSS - fixes #695 #1193, Offset between slider labels and positions  #695)
• In the image-* plugins, the maintain_aspect_ratio parameter now works as intended: when only one image dimension is specified and maintain_aspect_ratio is false, the unspecified dimension will be the image's original dimension, and the image will stretch or compress accordingly. (add render_on_canvas option, fix maintain_aspect_ratio - #891 #969 #1172 #1174, maintain_aspect_ratio parameter not working in image-* plugins #1172)
• Fixed a bug in video-* plugins that was preventing videos from automatically preloading. Thanks @mgorenstein! (Fix stimulus parameter naming in video response plugins #1171)
• Fixed a bug in audio-button-response that was producing an "undefined startTime" error. Thanks @esolitos! ([audio-button-response] Fix undefined startTime #1194)
• The audio-button-response plugin now calculates RTs based on the WebAudio clock when WebAudio is used, which is consistent with the other audio-* plugins.