How do I do printf debugging?

[joearms]

How do I do printf debugging?

In all programming langauages I know I stick print statements all over the

place to see what's going on - then I remove them when the program works.

What's the equivalent in developing TW plugins?

Specifically I've made a button like this:

<$button actions={{CommentButtonActions}}> Press Me To add a comment </$button>

Which I hope will do something when I click it

I now need to define CommentButtonActions

If this was regular Javascript I'd just write console.log(...) in my

JS and stare at the output.

What's the equivalent in TW code? What would I print out inside CommentButtonActions?

Cheers

/Joe

[Eric Shulman]

On Tuesday, January 8, 2019 at 8:47:29 AM UTC-8, joearms wrote:

How do I do printf debugging?

Specifically I've made a button like this:

<$button actions={{CommentButtonActions}}> Press Me To add a comment </$button>

Which I hope will do something when I click it

I now need to define CommentButtonActions

Try using <$action-setfield> to write your printf output to a tiddler.

-e

[PMario]

hi,

the dumpvariables macro may be an option

https://tiddlywiki.com/#dumpvariables%20Macro

-m

[joearms]

In general, what do you do when something goes wrong.

On several occasions, I've written some code (an action to be performed when something happens)

but I see nothing - I expect some output but there is none.

A typical case is an incorrect filter which returns nothing but I'd expected it to

return something  - the trouble is that I don't know it's the filter that has failed

it might be something else.

I don't know where or how to start debugging.

If it were C or JS I'd just start adding print statements at appropriate places printing out

variables

I guess I'd like a <$log ....> widget that did something like console.log(...) in Javascript

or printf in C -- just to know my code has been run.

I don't know how the code that evaluates a widget works - if a widget "fails" (meaning that it

breaks some rules of well-formed or something) I seem to get a silent error (meaning that there is no output)

It would be nice to have some kind of error tiddler - that logged silent errors - so I could read it

when debugging.

Do any of these things (logs, error tracing, etc.) exist?

Is there a tutorial on "How to debug a faulty TW program?"

Cheers

/Joe

[TonyM]

Joe,

The I think two most common debug methods, 

1. ask smaller questions. Put a filter in a list-links and check the results (use advanced Search Filter tab as well)
   
2. Use the browser inspect to see what was generated

You can also provide a single tiddler name or title rather than a more complex filter to test the result if that tiddler name was generated by the filter.

Regards

Tony

[TonyM]

Sorry, 

I cant advise for in Java script :(

tony

[alain.bo...@gmail.com]

For my plugin development (syncadaptor for node-solid-server) I use alert() to replace console.log()
It is a .js plugin