How to translate DSL syntax to scripted syntax

Question

Below is the code snippet in groovy DSL:

plugins {
  id("com.github.johnrengelman.shadow") version "5.2.0"
}

that is difficult for me to understand, if below is the corresponding scripted syntax:

plugins({
  id(
      {
        "com.github.johnrengelman.shadow", 
        version("5.2.0")
      }
   )
})

How to translate a DSL syntax to scripted syntax? Because scripted syntax is more readable syntax for me.

What do you mean with "scripted syntax" do you mean kotlin script instead of groovy script? — Leonard Brünings, Mar 19 '20 at 01:13
@LeonardBrünings this query has scripted syntax: https://stackoverflow.com/q/59507030/3317808 — overexchange, Mar 19 '20 at 01:14
So you just add the redundant parentheses back in and call it scripted syntax? — Leonard Brünings, Mar 19 '20 at 01:18
@LeonardBrünings yes.. exactly, but am confused how to convert plugin syntax written in DSL(given in the above query, for example)? — overexchange, Mar 19 '20 at 01:19

Leonard Brünings · Accepted Answer · 2020-03-19T01:31:54.407

1

The id(String) method in the plugins block returns a PluginDependencySpecImpl which has the methods version(String) and apply(boolean). So you just need to write it like so:

plugins ({
  id("com.github.johnrengelman.shadow").version("5.2.0")
})

The pattern at work is called Command Chain.

Groovy lets you omit parentheses around the arguments of a method call for top-level statements. "command chain" feature extends this by allowing us to chain such parentheses-free method calls, requiring neither parentheses around arguments, nor dots between the chained calls. The general idea is that a call like a b c d will actually be equivalent to a(b).c(d). This also works with multiple arguments, closure arguments, and even named arguments.

MrHaki has a nice explanation why this works here.

edited Mar 19 '20 at 01:31

answered Mar 19 '20 at 01:25

Leonard Brünings

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How do you know that there is dot between `id("com.github.johnrengelman.shadow")` and `version("5.2.0")`? this is the problem for me – overexchange Mar 19 '20 at 01:27
Read the explanation I linked from MrHaki and take a look at the links I added and then you'll see. – Leonard Brünings Mar 19 '20 at 01:29
How would I convert the complete script? – overexchange Mar 19 '20 at 01:34
1

You'll have to go over every block and see how it is defined, but honestly I don't recommend it, just use the official syntax like it is documented, otherwise you are just making it difficult for everyone else and you can't use examples. – Leonard Brünings Mar 19 '20 at 01:36

score 0 · Answer 2 · answered Mar 19 '20 at 03:18

0

The plugins DSL is the preferred approach of applying plugins.

The legacy plugins application (scripted syntax) equivalent is:

buildscript {
  repositories {
    maven {
      url "https://plugins.gradle.org/m2/"
    }
  }
  dependencies {
    classpath "com.github.jengelman.gradle.plugins:shadow:5.2.0"
  }
}

apply plugin: "com.github.johnrengelman.shadow"

That is a lot more to write than the plugins DSL.

The Gradle team has documented this as legacy. So whether you like the new plugins { } syntax or not, the legacy method will eventually go away.

answered Mar 19 '20 at 03:18

Cisco

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I did not understand your answer. above code is scripted syntax? – overexchange Mar 19 '20 at 03:20
Gradle has many newer ways of applying configurations. Generally, the older way to configures things is generally known as "scripted" syntax. – Cisco Mar 19 '20 at 03:22
ok...am trying to write gradle syntax like this: https://stackoverflow.com/q/60750513/3317808 – overexchange Mar 19 '20 at 03:30

How to translate DSL syntax to scripted syntax

2 Answers2