Accept default value in placeholders for unresolved property values

[diamondT]

Hi,

Here is a patch for accepting default values when a property key is not resolved.
Default value (if present) will be returned if all other resolution attempts fail (i.e. properties -> system properties -> env variable -> default value).

A few examples:

Given these initial values

("host", "example.com")
("port", "9090")
("fallback", "fallback value")

the following replacements will happen

raw value	replacement
${unknown:}	${unknown}
${unknown:defaultValue}	defaultValue
http://${uhost:localhost}:${uport:8080}	http://localhost:8080
http://${host:localhost}:${port:8080}	http://example.com:9090
${unknown:${fallback}}	fallback value
${unknown:${double.unknown}}	${double.unknown}
${unknown:with space}	with space
${unknown:with extra :}	with extra :
${malformed:defVal	${malformed:defVal
${malformed:with space	${malformed:with space
${malformed:with extra :	${malformed:with extra :
${unknown::}	:

Let me know what you think.

Thanks,

[khmarbaise]

If i correctly understand your code this will handle all the time the default values...I would say to add a flag which controls this behaviour and don't make it the default. Furthermore it would be nice having a documentation on the site with an example...

[diamondT]

Done.
I assume by "site" you meant the "index.apt" file. I've added a few lines there along with the examples mentioned in my previous comment.

Thanks,

[borisbrodski]

This is a really cool feature! I vote for it.

Just one note: In my opinion, ${test:} should be considered as a property with empty default (default="").
So the expansion may look like this:

raw value	replacement
${unknown}	${unknown}
${unknown:}

What do you think?

[vguna]

Sounds nice. Any news on this?

[OrangeDog]

Can this be revisited?

[oliverlockwood]

This would be incredibly useful. Perhaps one of the project maintainers could advise what's necessary to be able to merge this in and start using it? I'd rather not have to maintain a fork of this plugin for something which ought to be common usage!

[hinorashi]

hi guys, how about this, i'm still waiting for it :D

[eugenepaniot]

Me too, still waiting for it -(

[ProIcons]

bump

[drekbour]

2022 and still waiting...

[diamondT]

well after all this time there had to be a few conflicts :)
resolved.

[drekbour]

Hmmm. I actually wanted this behaviour for vanilla <properties> in the pom.xml. Does this plugin enable that in any way?

[diamondT]

resolved some more conflicts with the base branch 🔀

[slawekjaranowski]

@diamondT thanks for PR and for patience
This one is the oldest PR I was merged as I remember 😄

[diamondT]

better late than never :)
cheers!