XBlade-style php injection

XBladeLanguageInjector.java

package com.jetbrains.php.blade.injection;

import com.intellij.openapi.util.TextRange;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.psi.*;
import com.intellij.psi.xml.XmlAttribute;
import com.intellij.psi.xml.XmlAttributeValue;
import com.jetbrains.php.blade.BladeFileType;
import com.jetbrains.php.lang.PhpLanguage;
import org.jetbrains.annotations.NotNull;

/**
 * Should be registered in plugin.xml with
 * {@code <languageInjector implementation="com.jetbrains.php.blade.injection.XBladeLanguageInjector"/> }
 */
public class XBladeLanguageInjector implements LanguageInjector {
  @Override
  public void getLanguagesToInject(@NotNull PsiLanguageInjectionHost host, @NotNull InjectedLanguagePlaces injectionPlacesRegistrar) {
    if (!(host instanceof XmlAttributeValue)) return;
    if (host.getTextLength() < 2) return;
    PsiElement parent = host.getParent();
    if (!(parent instanceof XmlAttribute)) return;
    if (!isXBladeAttribute((XmlAttribute)parent)) return;
    injectionPlacesRegistrar.addPlace(PhpLanguage.INSTANCE, new TextRange(1, host.getTextLength() - 1), "<?php ", ";?>");
  }

  private static boolean isXBladeAttribute(@NotNull XmlAttribute attribute) {
    String attributeName = attribute.getName();
    if (!attributeName.startsWith(":")) return false;
    PsiFile file = attribute.getContainingFile();
    if (file == null) return false;
    VirtualFile virtualFile = file.getVirtualFile();
    if (virtualFile == null) return false;
    return virtualFile.getFileType() == BladeFileType.INSTANCE; //todo: add additional conditions
  }
}

Could you help me with the following issue? import com.jetbrains.php.lang.PhpLanguage doesn't seem to work:

The PHP jar is added to the project though:

Roman pointed out that I should add php-openapi.jar, that issue is solved 👍