feat: inject php language into html text elements

Author: xepozz

src/main/kotlin/com/github/tempest/framework/views/PHPLanguageInjector.kt

@@ -0,0 +1,26 @@
+package com.github.tempest.framework.views.injection
+
+import com.intellij.extapi.psi.ASTWrapperPsiElement
+import com.intellij.lang.ASTFactory
+import com.intellij.lang.ASTNode
+import com.intellij.psi.LiteralTextEscaper
+import com.intellij.psi.PsiLanguageInjectionHost
+import com.intellij.psi.impl.source.html.HtmlRawTextImpl
+import com.intellij.psi.impl.source.xml.XmlTextImpl
+
+abstract class InjectionHostWrapper(node: ASTNode) : ASTWrapperPsiElement(node), PsiLanguageInjectionHost {
+    override fun isValidHost(): Boolean = true
+
+    override fun updateText(text: String): PsiLanguageInjectionHost {
+        this.node.treeParent.replaceChild(this.node, ASTFactory.leaf(this.node.elementType, text))
+        return this
+    }
+}
+
+class XmlTextInjectionHostWrapper(val myElement: XmlTextImpl) : InjectionHostWrapper(myElement.node) {
+    override fun createLiteralTextEscaper() = myElement.createLiteralTextEscaper()
+}
+
+class HtmlTextInjectionHostWrapper(val myElement: HtmlRawTextImpl) : InjectionHostWrapper(myElement.node) {
+    override fun createLiteralTextEscaper() = LiteralTextEscaper.createSimple(this, false)
+}

src/main/kotlin/com/github/tempest/framework/views/injection/InjectionHostWrapper.kt

@@ -0,0 +1,81 @@
+package com.github.tempest.framework.views.injection
+
+import com.intellij.lang.Language
+import com.intellij.lang.injection.MultiHostInjector
+import com.intellij.lang.injection.MultiHostRegistrar
+import com.intellij.lang.tree.util.children
+import com.intellij.openapi.util.TextRange
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiLanguageInjectionHost
+import com.intellij.psi.html.HtmlTag
+import com.intellij.psi.impl.source.html.HtmlRawTextImpl
+import com.intellij.psi.xml.XmlAttribute
+import com.intellij.psi.xml.XmlAttributeValue
+import com.intellij.psi.xml.XmlText
+import com.intellij.psi.xml.XmlToken
+
+class PHPLanguageInjector : MultiHostInjector {
+    override fun getLanguagesToInject(
+        registrar: MultiHostRegistrar,
+        element: PsiElement
+    ) {
+        when (element) {
+            is XmlAttributeValue -> {
+                val attribute = element.parent as? XmlAttribute ?: return
+
+                if (!attribute.name.startsWith(':') || attribute.name.startsWith("::")) return
+
+                val injectableHost = element as? PsiLanguageInjectionHost ?: return
+
+                registrar
+                    .startInjecting(Language.findLanguageByID("PHP") ?: return)
+                    .addPlace("<?=", "?>", injectableHost, TextRange(0, injectableHost.textLength))
+                    .doneInjecting()
+            }
+
+            is HtmlTag -> {
+                element.children
+                    .mapNotNull { it as? HtmlRawTextImpl }
+                    .forEach { child->
+                        injectIntoText(HtmlTextInjectionHostWrapper(child), registrar)
+                    }
+            }
+
+            is XmlText -> {
+//                println("element: ${element.text}, ${element.javaClass.name} ${element is PsiLanguageInjectionHost}")
+                val injectableHost = element as? PsiLanguageInjectionHost ?: return
+                injectIntoText(injectableHost, registrar)
+            }
+        }
+    }
+
+    private fun injectIntoText(
+        element: PsiLanguageInjectionHost,
+        registrar: MultiHostRegistrar
+    ) {
+        val children = element.node.children().toList()
+            .filter { it is XmlToken }
+            .apply { if (size < 2) return }
+
+//        println("children: $children")
+        val openTag = children.firstOrNull()?.psi ?: return
+        val closeTag = children.lastOrNull()?.psi
+
+//        println("openTag: ${openTag.text}, closeTag: ${closeTag?.text}")
+        if ((openTag.text == "{!!" && closeTag?.text == "!!}") || (openTag.text == "{{" && closeTag?.text == "}}")) {
+            val language = Language.findLanguageByID("PHP") ?: return
+
+            val textRange = TextRange(openTag.textRangeInParent.endOffset, closeTag.startOffsetInParent)
+//            println("injecting ${language} into $element, $textRange")
+            registrar.startInjecting(language)
+                .addPlace("<?=", "?>", element, textRange)
+                .doneInjecting()
+        }
+    }
+
+    override fun elementsToInjectIn() = listOf(
+        XmlAttributeValue::class.java,
+        XmlText::class.java,
+        HtmlTag::class.java,
+    )
+}

src/main/kotlin/com/github/tempest/framework/views/injection/PHPLanguageInjector.kt

@@ -11,7 +11,7 @@
 
     <extensions defaultExtensionNs="com.intellij">
         <multiHostInjector
-                implementation="com.github.tempest.framework.views.PHPLanguageInjector"/>
+                implementation="com.github.tempest.framework.views.injection.PHPLanguageInjector"/>
         <webSymbols.webTypes
                 source="META-INF/webTypes.json"
                 enableByDefault="true"/>