CODEWITHSUNDEEP
regexmavenmaven-replacer-plugin
FrustratedWithFormsDesigner
FrustratedWithFormsDesigner

Reputation: 27496

Maven replacer plugin - repeat while matches exist

I am using the maven replacer plugin and I've run into a situation where I have a regular expression that matches across lines which I need to run on the input file until all matches have been replaced. The configuration for this expression looks like this:

<regexFlags>
    <regexFlag>DOTALL</regexFlag>
</regexFlags>
<replacements>   
    <replacement>
        <token>\@([^\n\r=\@]+)\@=([^\n\r]*)(.*)(\@default\.\1\@=[^\n\r]*)(.*)</token>
        <value>@$1@=$2$3$5</value>
    <replacement>
<replacements>

The input could look like this:

@d.e.f@=y
@a.b.c@=x
@h.i.j@=aaaa
@default.a.b.c@=QQQ
@asdfasd.fasdfs.asdfa@=23423
@default.h.i.j@=234
@default.RR.TT@=393993

and I want the output to look like this:

@d.e.f@=y
@a.b.c@=x
@h.i.j@=aaaa

@asdfasd.fasdfs.asdfa@=23423

@default.RR.TT@=393993

The intention is to re-write the file, but without the tokens with a @default prefix, where another token without the prefix has already been defined.

@default.a.b.c@=QQQ and @default.h.i.j@=234 have been removed from the output because other tokens already contains a.b.c and h.i.j.

The current problem I have is that the replacer plugin only replaces the first match, so my output looks like this:

@d.e.f@=y
@a.b.c@=x
@h.i.j@=aaaa

@asdfasd.fasdfs.asdfa@=23423
@default.h.i.j@=234
@default.RR.TT@=393993

Here, @default.a.b.c=QQQ is gone, which is correct, but @default.h.i.j@=234 is still present.

If I were writing this in code, I think I could probably just loop while attempting to match on the entire output, and break when there are no matches. Is there a way to do this with the replacer plugin?

Edit: I may have over simplified my example. A more realistic one is: 

@d.e.f@=y
@a.b.c@=x
@h.i.j@=aaaa
@default.a.b.c@=QQQ
@asdfasd.fasdfs.asdfa@=23423
@default.h.i.j@=234
@default.RR.TT@=393993
@x.y.z@=0
@default.q.r.s@=1
@l.m.n@=8.3
@q.r.s@=78
@blah.blah.blah@=blah

This shows that it's possible for a default.x.x.x=y to precede a x.x.x=y token (as @default.q.r.s@=1 preceedes @q.r.s@=78`), my prior example wasn't clear about this. I do actually have an expression to capture this, it looks a bit like this:

\@default\.([^\n\r=@|]+)@=([^\n\r|]*)(.*)@\1@=([^\n\r|]*)(.*)

I know line separators are missing from this even though they were in the other one - I was experimenting with removing all line separators and treating it as a single line but that hasn't helped. I can resolve this problem simply by running each replacement multiple times by copying and pasting the configurations a few times, but that is not a good solution and will fail eventually.

Upvotes: 1

Views: 1905

Answers (2)

FrustratedWithFormsDesigner
FrustratedWithFormsDesigner

Reputation: 27496

It doesn't look like the replacer plugin can actually do what I want. I got around this by using regular expressions to build multiple filter files, and then applying them to the resource files.

My original goal had been to use regular expressions to build a single, clean, and tidy filter file. In the end, I discovered that I was able to get away with just using multiple filters (not as clean or tidy) and apply them in the correct order.

Upvotes: 0

alpha bravo
alpha bravo

Reputation: 7948

I don't believe you could solve this problem as is, a work-around is to reverse the order of the file top to bottom, perform lookahead regex and then reverse the result order
pattern = @default\.(.*?)@[^\r\n]+(?=[\s\S]*@\1@) Demo

another way (depending on the capabilities of "Maven") is to run this pattern 

@(.*)(@[\s\S]*)@default\.\1.*

and replace with @$1$2 Demo in a loop until there are no matches

then run this pattern 

@default\.(.*)@.*(?=[\s\S]*\1)

and replace with nothing Demo in a loop until there are no matches

Upvotes: 1

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