When cola.js fails, how do you find out what went wrong?
I don't have a minimal reproducible example, because that will likely take hours of debugging to make, and if I had it, then it wouldn't be an example of what I'm asking about. I'm hoping to hear of a way to quickly find out what's gone wrong. Presumably it's some bad data in my graph. But how can I tell what the bad data is?
The screenshot below illustrates a typical situation where something has gone wrong. Various NaNs are reported, there are a bunch of Uncaught TypeErrors, and an Assertion fails. There are a whole lot of local variables, all named with a single letter. Clicking and looking at them shows that a NaN got into a coordinate somewhere, as suggested by the previous error messages. It looks like sometime earlier, something got a null when it needed some sort of list-like data structure. How can I quickly find out what was the bad data that got into the graph?
I'm using cola.v3.min.js.
Details
I'm looking for a general approach to finding this kind of error, but here's the specific data that produced the errors in this example. Each line is the argument passed to cy.add() (as suggested by Stepan T.—and printing out everything passed to cy.add() might turn out to be the first step of the answer!).
{"group":"nodes","data":{"id":1,"label":"Workspace","parent":[]},"position":{"x":45,"y":0}}
{"group":"nodes","data":{"id":2,"label":"Target(121)","parent":[1]},"position":{"x":5,"y":0}}
{"group":"nodes","data":{"id":3,"label":"WantFullySourced","parent":[]},"position":{"x":50,"y":0}}
{"group":"nodes","data":{"id":4,"label":"Brick(120)","parent":[1]},"position":{"x":10,"y":0}}
{"group":"nodes","data":{"id":5,"label":"Avail","parent":[]},"position":{"x":55,"y":0}}
{"group":"nodes","data":{"id":6,"label":"Brick(1)","parent":[1]},"position":{"x":15,"y":0}}
{"group":"nodes","data":{"id":7,"label":"Avail","parent":[]},"position":{"x":60,"y":0}}
{"group":"nodes","data":{"id":8,"label":"Brick(2)","parent":[1]},"position":{"x":20,"y":0}}
{"group":"nodes","data":{"id":9,"label":"Avail","parent":[]},"position":{"x":65,"y":0}}
{"group":"nodes","data":{"id":10,"label":"Brick(3)","parent":[1]},"position":{"x":25,"y":0}}
{"group":"nodes","data":{"id":11,"label":"Avail","parent":[]},"position":{"x":70,"y":0}}
{"group":"nodes","data":{"id":12,"label":"Brick(4)","parent":[1]},"position":{"x":30,"y":0}}
{"group":"nodes","data":{"id":13,"label":"Avail","parent":[]},"position":{"x":75,"y":0}}
{"group":"nodes","data":{"id":14,"label":"Brick(5)","parent":[1]},"position":{"x":35,"y":0}}
{"group":"nodes","data":{"id":15,"label":"Avail","parent":[]},"position":{"x":80,"y":0}}
{"group":"nodes","data":{"id":16,"label":"NumericalRelationScout","parent":[1]},"position":{"x":40,"y":0}}
{"group":"nodes","data":{"id":17,"label":"OperandView","parent":[1]},"position":{"x":0,"y":0}}
{"group":"edges","data":{"id":"2.member_of.1.members","source":2,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"4.member_of.1.members","source":4,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"6.member_of.1.members","source":6,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"8.member_of.1.members","source":8,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"10.member_of.1.members","source":10,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"12.member_of.1.members","source":12,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"14.member_of.1.members","source":14,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"16.member_of.1.members","source":16,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"17.member_of.1.members","source":17,"source_port_label":"member_of","target":1,"target_port_label":"members","weight":0.5}}
{"group":"edges","data":{"id":"3.taggees.2.tags","source":3,"source_port_label":"taggees","target":2,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"2.support_from.3.support_to","source":2,"source_port_label":"support_from","target":3,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"3.support_from.2.support_to","source":3,"source_port_label":"support_from","target":2,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"5.taggees.4.tags","source":5,"source_port_label":"taggees","target":4,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"4.support_from.5.support_to","source":4,"source_port_label":"support_from","target":5,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"7.taggees.6.tags","source":7,"source_port_label":"taggees","target":6,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"6.support_from.7.support_to","source":6,"source_port_label":"support_from","target":7,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"9.taggees.8.tags","source":9,"source_port_label":"taggees","target":8,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"8.support_from.9.support_to","source":8,"source_port_label":"support_from","target":9,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"11.taggees.10.tags","source":11,"source_port_label":"taggees","target":10,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"10.support_from.11.support_to","source":10,"source_port_label":"support_from","target":11,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"13.taggees.12.tags","source":13,"source_port_label":"taggees","target":12,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"12.support_from.13.support_to","source":12,"source_port_label":"support_from","target":13,"target_port_label":"support_to","weight":2}}
{"group":"edges","data":{"id":"15.taggees.14.tags","source":15,"source_port_label":"taggees","target":14,"target_port_label":"tags","weight":0.5}}
{"group":"edges","data":{"id":"14.support_from.15.support_to","source":14,"source_port_label":"support_from","target":15,"target_port_label":"support_to","weight":2}}
The object passed to cy.layout() had a circular structure, so JSON.stringify() wouldn't print it. Adding the getCircularReplacer() function recommended here seemed to crash the browser. But manually removing elements from the layout object exposed the error: in a relative alignment constraint (documented under API here), I had an offset of '0' where I needed a 0, i.e. a string where a number was needed.
OK, happily that problem is now fixed. That still leaves the original question: is there a faster way to find errors like that? (The static-typing advocates are surely cackling by now.)
I am trying to create a new GUI element within DrRacket's text window, like picts or syntax objects. As far as I can tell, the most standard way of doing this is with a snip%.1
Unfortunately, the documentation for creating new snips, while comprehensive, is a bit impenetrable and leaves some questions to be answered.
For starters, what is the difference between a snip% and a snip-class%? Why do these need to be separated out into two classes, rather than simply being combined into one class? Is it because multiple snips will use one snip class?
Second off, what is snip-reader<%>? Not only why does it need to be a separate class, but why is the module providing it supposed to be installed?2 If it does need to be a new class, why can't it just be referred to directly. Why go through this whole process of constructing and then parsing a string of the form: "(lib ...)\n(lib ...)"?
I mean, there might now be any reason for this design, and it might just be a remnant of an old API. If so, has anyone thought of making a new more consistent API? Or if there is a reason for this design, can you please tell me what it is, as the docs don't seem to make that clear.
I mean, as of right now, I can copy/paste the sample given in the docs on creating a new snip. But I'm having a hard time understanding the design going on here, so I can use them properly.
1I know there are other ways to do it, but I also want to have interactive buttons and whatnot.
2I know it doesn't need to be installed as a library per se, but the documentation seems to strongly push you in that direction.
Okay, I think I finally found the answer. Broadly speaking:
The snip% class includes the methods for drawing the snip, telling the editor how much space to reserve for the picture, and handling events such as mouse clicks.
Next, the snip-class% class is used for encoding and decoding snips. This must be a separate class because when saved to a file, the editor needs to encode what type of snip it is, and for obvious reasons it can't just put the literal snip% class in there. The value it stores in the file is the snip-class%'s 'class name'. This can be anything, and as long as the editor has the classname associated to a snip-class%, it can be loaded. Additionally, if it is of the form "(lib ...)" or "(lib ...) (lib ...)" Racket will just automatically load it into the list for you.
Nothing 'needs' to be installed per se, its just the easiest way to go about it. Otherwise you manually need to tell the editor how to handle the snip before actually loading the file.
We're using Freemarker version 2.3.16, and I've just tracked down a weird bug in one of our apps. It came down to there now being hyphens in some of our product code strings. The codes are used to pull hashes of localized text from the global scope using .vars.
Reducing the issue brought me to an example that anyone can try:
${.vars["foo-bar"]} in a template outputs 0
${.vars["foo+bar"]} outputs nullnull
${.vars["foobar"]} correctly triggers an InvalidReferenceException
All three should trigger exceptions. Instead, it appears the .vars parameter string is being evaluated! :-(
http://freemarker.sourceforge.net/docs/app_faq.html#faq_strange_variable_name implies this should work.
I saw mention of a similar issue a few weeks ago on the Freemarker mailing list, and it was suggested to prefix the parameter string with "#". That might work with other hashes, but it does NOT work with .vars. I just took a working example (.vars["resources_title"]) and changing it made it throw an InvalidReferenceException (.vars["#resources_title"]). I also tried it on the hyphenated reference, and it also threw the exception.
Upgrading to 2.3.18 did not seem to make a difference.
Sorry for the delay. After some good mailing-list help on places to put breakpoints, here's I wrote back to the list on June 10th:
Short story: It's not a Freemarker issue. Rather the Struts team chose to hard-wire Freemarker to treat .vars names as OGNL expressions, and there seems no way to tell OGNL to not parse them. So under Struts, "-" and "+" (and possibly other characters) cannot appear in .vars names.
Long story...
freemarker.core.BuiltinVariable (line 192) is where Freemarker starts to process .vars expressions
freemarker.core.Environment (line 1088) hands control over to the "rootDataModel" which the Struts team hard-wired to be an instance of org.apache.struts2.views.freemarker.ScopesHashModel
line 70 of that class (using version 2.1.8.1 of Struts) calls "stack.findValue"; "stack" has been wired to be an instance of com.opensymphony.xwork2.ognl.OgnlValueStack
at line 236 this class in turn asks an instance of OgnlUtil to find the object, and that's where the name is assumed to be an OGNL expression and is parsed, turning "foo-bar" into ( foo - bar )
At no point along the way does there seem to be a choice to NOT treat the .vars name as an expression (a comment in FreemarkerResult hints at the possibility, but the code doesn't follow through). In theory I could have my implementation of FreemarkerManager create a variant of ScopesHashModel, but that would take a lot of work to change all the associated classes with it.
(Nor does there seem to be a way to escape "-" characters in OGNL expressions. Seems there was discussion 5-6 years ago to do this, but.... .vars( "foo\\-bar" ) fails on finding "-" after "\", so presumably "-" isn't escapable?)
:-(
I'm not clear what the use-case is for treating .vars names as expressions... but I don't think Struts is going to change, now. Rather than override a half dozen Struts classes, I instead changed the code that loads our ResourceBundles into the value stack: it now changes the names to replace "-" and "_", and likewise my .vars names are changed the same way in the template and... tada. It works. Woo.
Works for me. And like already mentioned on the freemarker-user mailing list: maybe you use a strange data model, or even a fancy ObjectWrapper. But a discussion like this is probably better suited for the freemarker-user mailing list...
It works if it added with escape foo\-bar.
"Only single backslash"
Since freemarker version 2.3.22 is it possible to use dot (.), minus sign (-) or colon (:) in a variable name (details here).
In my case, it fails if I tried to use with freemarker 2.3.21 variables like :
api["x-link"]
If I change freemarker to version 2.3.22 it works.
I'm relatively new to Watir but can find no good documentation (examples) regarding how to check if an element exists. There are the API specs, of course, but these make precious little sense to me if I don't find an example.
I've tried both combinations but nothing seems to work...
if browser.image (:src "/media/images/icons/reviewertools/editreview.jpg").exists
then...
if browser.image (:src "/media/images/icons/reviewertools/editreview.jpg").exists?
then...
If anyone has a concrete suggestion as per how to implement this, please help! Thanks!
It seems you are missing a comma between parameters.
Should be
if browser.image(:src, "/media/images/icons/reviewertools/editreview.jpg").exists?
Also you can find this page useful in future to know what attributes are supported.
The code you posted should work just fine.
Edit: Oops, wrong. As Katmoon pointed out, there is a missing comma.
browser.image(:src "/media/images/icons/reviewertools/editreview.jpg").exists?
One problem you may get caught up in is if the browser variable you specified is actually an element that doesn't exist.
e.g.
b = Watir::IE.start(ipAddress)
b.frame(:name, "doesntExist).image(:src "/media/images/icons/reviewertools/editreview.jpg").exists?
The above code will throw a Watir::UnknownFrameException. You can get around this by first verifying the frame exists or by surrounding the code in a begin/rescue block.
Seems like you are using it correctly. Here is an old RDoc of Watir.
Does it not work because Watir cannot find it? Hard to tell because there is no source or link to the page that is being tested. I think that I only use image.exists?. In general, errors that come from when the image exists but is not found are:
The how is not compatible with the element type. There is a cheatsheet to help you see which object types can be found with different attributes here.
The what is not correct. You may have to play with that a little bit. Consider trying a regex string to match it such as browser.image(:src, /editreview.jpg/). As a last resort, maybe use element_by_xpath, but there are maintenance costs with that.
The location is not correct. Maybe the element is in a frame or something like that. browser.frame("detail").image(:src, /editreview.jpg/).
Try those, but please let me know what worked. One more thing, what are you checking for? If it's part of the test criteria, you can handle it that way. If you need to click on it, then forget the .exists? and just click on it. Ruby will let you know if it's not there. If you need it to be grace, learn about begin/rescue.
Good luck,
Dave