Moodle 3.1.1, PHP7 and clean theme
When open a formulas question it appears an image in the lower right part of the page when the mouse is over it shows the tooltip : Format check initialization fail (1/190)
It seems to be that the png image which is in the folder of question/type/formulas/pix cannot be initialized
I have purged all caches but don't know what to do more. Any ideas?
It is PHP7 to blame?
Hi,
Since this is not a theme related issue entirely, I am moving it over to Tim Hunt in the QUIZ Forum as he is the Questions Guru and certainly more knowledgeable about this, PHP7 and Moodle.
Thanks
Mary
I answer myself, it was a browser issue, it happens in Chrome only.
For the moment formulas question type works fine in Moodle3.1.1 & PHP7
Sorry for the inconvenience
I was thinking of fixing this if it is a bug, be it browser related, but could not find "formula" in the moodle/question/type/ directory.
See here: https://github.com/lazydaisy/moodle/tree/MOODLE_31_STABLE/question/type
Can you tell me which type you used exactly, please?
Thanks
Mary
This is an addon in the database.
Thanks for your effort.
This is the link to the plugin
https://moodle.org/plugins/qtype_formulas
It seems only happens with CHROME using a MAC. It happens I have recently upgraded to El Capitan, in older versions I didn't noticed it
See the red triangle in the right lower part of the image.
This icon is used for warning you are writing forbidden characters in an answer field, it appears beside the answer field. Obviously this feature doesn't work now
I have exactly the same problem.
It occurs in PHP 5.6 and in PHP 7.0 (I just did a short test).
The triangle is shown in Chrome, Opera and Vivaldi, but not in Firefox or Edge.
Thanks for reporting this.
It is strange thing, first only happened using Chrome with Mac (not in Safari and Firefox), later it appeared in Chrome with Windows. It seems that some browser actualization has created a CSS problem.
Any idea how to solve it would be appreciated
The error happens in line 756 of the file formatcheck.js
['algebraic_formula', false, 'a**b'],
If you remove this line, the error is gone. But also the extra formula check.
Does anyone has a clue why some browsers return true and other browsers false on evaluating a**b?
It works, thanks.
May I ask you what type of procedure do you use to detect where the error happens.
Thanks a lot for your clear explanation, I'm not a programmer but I can understand the procedure
On another note, I also have this error in Chrome but I can not complain too much because, for me, it's almost better if this routine is not working, although the red error triangle at the bottom right of the screen is a bit distracting.
In my use of the Formulas question, all the answers are either a number or a number and a unit. If {_0} and {_0}{_u} are used, the width of the input box indicates whether students must enter a number or a number and a unit. If {_0} and {_0} {_u} (separated by a space) are used, the fact that there are either one or two input boxes indicates even more clearly what students should enter. Hence the routine's recall of what should be entered is somewhat superfluous.
The syntax checking, for example for an input of 10e3 mm^2, also seems a bit superfluous, since in any case students have to be reminded of the syntax rules. Also since the verification is done as the answer is input, it may indicate an error while the input is not complete, for example when it is at 10e3 mm^. See the first screenshot below.
So assuming that the routine is not absolutely necessary, another advantage is to gain some space. Since my sub-questions are generally arranged one above the other in a table, I have to provide space between each sub-question when the routine is active, so that the message of a sub-question does not cover the input box of the next sub-question. The Enter key does not release from an input box and it is only natural to click the next box below to enter the next response, which is impossible if this box is hidden. With the routine inactive, the sub-questions can be moved closer together and the answer pages becomes shorter, reducing scrolling. The screenshots below illustrate the above points.
Thanks to Bernat Martinez for bringing this point up and to Renaat Debleu for showing how to disable the routine if wanted.
Dominique,
You can customize the display of the error checking to suit your needs by editing some lines at the beginning of the formatcheck.js file
And fortunately these lines are well commented so it's easy to see what they do:
var use_format_check = true; // If it is set to false, no format check will be used and initialized.
var show_hinting_type = null; // Show the type hinting under the input box, such as 'Number', 'Unit'. null means use the individual setting in variable types below.
var show_interpretation = null; // Show the interpretation of the formula under the input box. null means use the individual setting in variable types below.
var show_warning = null; // Show the warning sign if the input is wrong/not interpretable. null means use the individual setting in variable types below.
var unittest_fail_show_icon = true; // Show an icon at the low right corner if the format check testing fails
var unittest_fail_show_details = false; // Show the detail test case that it fails.
In your case you can set both show_hinting_type and show_interpretation to false.
Hon Wai Lau's code even permit to set some of these flags to true or false only for numbers or for algebraic formulas for instance, see the lines
var types = [
['unit', true, true, true], // For the unit input box.
['number', true, true, true], // For the number input box.
['number_unit', true, true, true], // Input box with number and unit together.
['numeric', true, true, true], // Allow the combination of numbers and operators + - * / ^ ( ).
['numeric_unit', true, true, true], // Input box with numeric and unit together.
['numerical_formula', true, true, true], // Allow the combination of numbers, operators and functions.
['numerical_formula_unit', true, true, true], // Input box with numerical formula and unit together.
['algebraic_formula', true, true, true], // Allow the combination of numbers, operators, functions and variables.
['editing_unit', false, true, true] // Used for the unit in editing interface.
];
Thanks (works!)
Yes, it is still happening in Chrome and now in Firefox too. But not in Safari.
Thanks for having a look at this issue, we are extremely happy with formulas question
Hello,
I just discovered this thread. What would be the best way to solve this issue ? Now in december 2017 with what browsers does it appear ( I tested with chrome latest version and can see the problem)
Hello,
Now in version 3.4 it happens in Chrome, Firefox and Safari
Well at least this is consistent
I wil try to study the problem. Comments welcome.
This is totally unrelated.
As Hon Wai said
"During the initialization formatcheck.js it will perform 190 checks to ensure the javascript works exactly the same as the PHP backend"
So you may wonder where are the tests for the php backend?
They are in the variables.php file (this file is the workhorse of the formulas question type where all the magic is done and I learned the hard way that you have to be very cautious when you make any change to it)
They are commented and you have to uncomment one line at the end to run the tests.
Since a long time my thinking was that today it would be better to have automated tests.
Now that each time I push a new commit at my github automated tests are run, see https://travis-ci.org/jmvedrine/moodle-qtype_formulas, but don't be frightened by all the orange and red here, most of the "errors" and "violations" are just coding style problems that are unimportant (and very risky) to fix.
So this morning I took the task to transform all Hon Wai Lau tests in variables.php into phpunit tests, the result is here :
https://github.com/jmvedrine/moodle-qtype_formulas/blob/master/tests/variables_test.php
Good news : most of the tests are passing, in fact all of them minus 4 (see Travis job, the phpunit section is all green)
So we know that the formulas engine is working, good for all formulas users
But 4 tests are falling (those that are currently commented in my file)
a=3 6; in the variable assignement test produces a parseerror unexpected '$a' (T_VARIABLE) here
https://github.com/jmvedrine/moodle-qtype_formulas/blob/master/variables.php#L946
and 3 tests are failing in the algebraic formula test (a- , *a and a**b)
But the good new is that all these tests have a false as their first element so it's the sign that the parser fails on expressions that are incorrect
So most probably correct answers from students are correctly parsed and graded.
But I still need to investigate what is causing these failures.
This rather funny, when I said "This is totally unrelated." I was completely wrong
It seems that in all modern browser's javascript engine that I have tested a**b is equivalent to a^b and this is why the Format check initialization was failing
just changing the line in formatcheck.js to ['algebraic_formula', true, 'a**b'],
solve the problem reported by the original poster of this thread.
I don't know when this change was decided but the same operator was introduced in php 5.6 (I seems to remember that ** have been used in Python for ages)
So this also solve one of my 4 problems in the variables tests.
Perfect!!! It works
Thanks a lot, Jean-Michel.
So I think we can consider this problem as solved.
The only problem would be for sites that want to support old browsers. in that case it is better to comment that line in formatcheck.js
Perfect!!!
THX
Just a note on this thread that the 2 remaining tests that had problems (a- and *a) are now fixed this was caused by a change in PHP 7.x for the eval function : before PHP 7.x if the expression to evaluate had a syntax error, the eval function just returned false. Now it throws an exception and stops the script.
Including this line in a try { } catch block resolved the issue.
See https://moodle.org/mod/forum/discuss.php?d=366549 for the details