How to set JAR version with variable in Gradle?

Question

If I write

ext.nd4j_version = "1.0.0-beta2"
ext.nd4j_backend = "nd4j-native-platform"

dependencies {

    compile group: 'org.nd4j', name: '${nd4j_backend}', version: '${nd4j_version}'

it is unable to find artifacts.

And if I write

nd4j_version = "1.0.0-beta2"
nd4j_backend = "nd4j-native-platform"

dependencies {

    compile group: 'org.nd4j', name: '${nd4j_backend}', version: '${nd4j_version}'

then it is able to find artifact, but issues a warning

Could not set unknown property 'nd4j_version' for root project

UPDATE

The following also doesn't work

ext.nd4j_version = "1.0.0-beta2"
ext.nd4j_backend = "nd4j-native-platform"


dependencies {

    compile group: 'org.nd4j', name: '${project.ext.nd4j_backend}', version: '${project.ext.nd4j_version}' // works

and the following

ext.nd4j_version = "1.0.0-beta2"
ext.nd4j_backend = "nd4j-native-platform"


dependencies {

    compile group: 'org.nd4j', name: '${rootProject.ext.nd4j_backend}', version: '${rootProject.ext.nd4j_version}'

and the following

ext {
    nd4j_version = "1.0.0-beta2"
    nd4j_backend = "nd4j-native-platform"
}


dependencies {

    compile group: 'org.nd4j', name: '${project.nd4j_backend}', version: '${project.ext.nd4j_version}'

Please give an answer with an explanation, not just random working syntax.

Possible duplicate of [How to set a version of dependencies on Gradle?](https://stackoverflow.com/questions/53000509/how-to-set-a-version-of-dependencies-on-gradle) — Martin Zeitler, Oct 27 '18 at 20:21
`"${project.ext.nd4j_version}"` should work (the location of the variable definition in the `build.gradle` matters, because it either has refer to `project` or to `rootProject`). — Martin Zeitler, Oct 27 '18 at 20:24
@MartinZeitler how would I know this from Gradle doc without reading it in it's entirety? — Dims, Oct 27 '18 at 20:28
much of that only gets obvious while working with it. would suggest to add `ext {nd4j_version = "1.0.0-beta2"}` to the root project's `build.gradle` and then reference it within a module as `"${rootProject.ext.nd4j_version}"` ...which makes sense, when occasionally having to update several modules. — Martin Zeitler, Oct 27 '18 at 20:34
eg. `compile "org.nd4j:nd4j-native-platform:${rootProject.ext.nd4j_version}"` ...but this only makes sense with several modules; for a single module, it's sufficient to define it at the module level. the `"` is important there, else there won't be any string substitution. — Martin Zeitler, Oct 27 '18 at 20:40

Kushagra Goyal · Answer 1 · 2018-10-27T20:32:11.843

2

Remove the '{$}' and use the variable as it is.

ext.nd4j_version = "1.0.0-beta2"
ext.nd4j_backend = "nd4j-native-platform"

dependencies {
   compile group: 'org.nd4j', name: nd4j_backend, version: nd4j_version

EDIT: You can also use double-quotes with ${}:

dependencies {
   compile group: 'org.nd4j', name: "${nd4j_backend}", version: "${nd4j_version}"

edited Oct 27 '18 at 20:32

answered Oct 27 '18 at 20:26

Kushagra Goyal

252
1
8

Okay, but what if I want to use `$`? – Dims Oct 27 '18 at 20:27
Edited my answer! :) – Kushagra Goyal Oct 27 '18 at 20:32
Ok it doesn't work for me: if variables prepended by `ext`, it can't find them with `${variable_name}` – Dims Oct 27 '18 at 20:34
What version of `Gradle` are you using? – Kushagra Goyal Oct 27 '18 at 20:35
Why version can matter? Can you explain why `nd4j_backend` works and `'${nd4j_backend}'` doesn't? Why it takes names from different contexts? – Dims Oct 28 '18 at 08:17
2

note that `'${nd4j_backend}'` cannot work as you need to use `"` character to enable string interpolation, see more details here : http://groovy-lang.org/syntax.html#_double_quoted_string – M.Ricciuti Oct 28 '18 at 08:48

How to set JAR version with variable in Gradle?

1 Answers1