XML file editing with the groovy XML library is unwieldy in kotlin

[JLLeitschuh]

Trying to do something like this:

http://mrhaki.blogspot.com/2016/03/gradle-goodness-add-spring-facet-to.html

idea {
    module {
        iml {
            withXml {
                // Get root of module as groovy.util.Node.
                def moduleRoot = it.asNode()
                 
                // Find if component with name 'FacetManager'
                // is already set.
                def facetManager = moduleRoot.component.find { component -> component.'@name' == 'FacetManager'}
                if (!facetManager) {
                    // Create new component with name 'FacetManager'
                    facetManager = moduleRoot.appendNode('component', [name: 'FacetManager'])
                }
                 
                // Find Spring facet it might already be there.
                def springFacet = facetManager.facet.find { facet -> facet.'@type' == 'Spring' && facet.'@name' == 'Spring' }
                if (!springFacet) {
                    // If not set create new facet node with name 'Spring'
                    // and type 'Spring' and apply a default configuration.
                    springFacet = facetManager.appendNode('facet', [type: 'Spring', name: 'Spring'])
                    springFacet.appendNode('configuration')
                }
            }
        }
    }
}

Is incredibly hard in kotlin because many of the methods rely on gradle's duck typing system.

[JLLeitschuh]

Here's another example:

fun getEclipseFormatterSettings() : Collection<Pair<String, String>> {
    val eclipseFormatterSettingsXml = file("${rootProject.projectDir}/eclipse-formatter-settings.xml")
    val eclipseFormatter = XmlParser().parse(eclipseFormatterSettingsXml)
    return ((eclipseFormatter["profile"] as NodeList)[0] as Node).children().map {
        val node = it as Node
        node.attribute("id").toString() to node.attribute("value").toString()
    }
}

[eskatos]

Hi @JLLeitschuh, thanks for the report.

XmlProvider exposes the underlying XML data in two useful flavors: groovy.util.Node and org.w3c.dom.Element. The former is meant to be used in Groovy build scripts and rely on Groovy's duck typing system like you said. The latter could be used with kotlinx.dom in a more Kotlin-way.

withXml {
  def moduleRoot = it.asElement() // instead of asNode()            
}

I didn't try that myself yet, I'll give it a shot soon, in the meantime I hope this helps.

[JLLeitschuh]

I did end up using that to solve the problem. Good suggestion.

[eskatos]

@JLLeitschuh would you mind sharing a snippet of the resulting build script?

[JLLeitschuh]

configure<IdeaModel> {
    module.apply {
        generatedSourceDirs.apply {
            add(generatedDaoFile)
            add(generatedJobFile)
        }
        iml.apply {
            withXml {
                val moduleRoot = it.asElement()
                val doc = moduleRoot.ownerDocument

                fun NodeList.asElementList() = asList().filterIsInstance<Element>()

                val facetManager = moduleRoot
                    .getElementsByTagName("component")
                    .asElementList()
                    .singleOrNull { it.getAttribute("name") == "FacetManager" }
                    ?: moduleRoot
                    .appendChild(doc.createElement("component").apply {
                        setAttribute("name", "FacetManager")
                    }) as Element

                // Add spring facet
                facetManager
                    .getElementsByTagName("facet")
                    .asElementList()
                    .singleOrNull { it.getAttribute("name") == "Spring" && it.getAttribute("type") == "Spring" }
                    ?: facetManager
                    .appendChild(doc.createElement("facet").apply {
                        setAttribute("name", "Spring")
                        setAttribute("type", "Spring")
                        appendChild(doc.createElement("configuration"))
                    })

                // Add AspectJ facet
                facetManager
                    .getElementsByTagName("facet")
                    .asElementList()
                    .singleOrNull { it.getAttribute("name") == "AspectJ" && it.getAttribute("type") == "AspectJ" }
                    ?: facetManager
                    .appendChild(doc.createElement("facet").apply {
                        setAttribute("name", "AspectJ")
                        setAttribute("type", "AspectJ")
                        appendChild(doc.createElement("configuration").apply {
                            appendChild(doc.createElement("option").apply {
                                setAttribute("name", "aspectPath")
                                appendChild(doc.createElement("projectLibrary").apply {
                                    appendChild(doc.createElement("option").apply {
                                        setAttribute("name", "name")
                                        setAttribute("value", "Gradle: org.springframework:spring-aspects:$springVersion")
                                    })
                                })
                            })
                        })
                    })
            }
        }
    }
}

// Helper Utilities
fun NodeList.asList() = (0..length).map { item(it) }

[baron1405]

I just started using kotlinx.dom and it results in much more succinct code. Great project and it is from JetBrains!

[eskatos]

Closing as answered.