Grails 5脚手架视图模板嵌入代码及自定义类导入失败问题求助

Hey there! Let's break down solutions to your two Grails 5 questions:

Grails 5 uses GSP (Groovy Server Pages) for scaffold templates, which supports several straightforward ways to embed Groovy code:

• Inline execution logic: Wrap code that runs during page rendering (without returning output) in <% %> tags:

  <% 
  // Example: Fetch a customer and run quick logic
  def customer = tst.Customer.get(params.id)
  if (!customer) {
      flash.message = "Customer not found"
  }
  %>
  

• Output expressions: Use ${ } to print variable values or evaluate expressions directly within HTML:

  <div class="customer-details">
      <p>Name: ${customer?.name ?: 'No name provided'}</p>
      <p>Email: ${customer?.email}</p>
  </div>
  

• Page-wide declarations: For reusable methods or global imports, use <%! %> (this code runs once when the page is initialized, not on every render):

  <%!
  // Import your custom class for use anywhere in the view
  import tst.Customer
  
  // Define a helper method to reuse across the page
  String formatStatus(Customer customer) {
      customer.active ? 'Active' : 'Inactive'
  }
  %>
  

Note that scaffold templates are stored in src/main/groovy/grails/scaffolding/templates by default. After modifying them, re-run your scaffold generation command (like grails generate-all tst.Customer) to apply changes to your actual views.

The error you hit comes from using outdated, incomplete JSP-style syntax (@ page import="tst.Customer") that Grails 5's stricter GSP engine no longer supports. Grails 2 had more lenient support for mixed JSP/GSP syntax, but Grails 5 relies on Groovy-native or proper GSP directives.

Here are the correct, supported ways to import your tst.Customer class:

• Inline Groovy import: For use within a specific code block:

  <% 
  import tst.Customer
  def newCustomer = new Customer(name: "Test User")
  %>
  

• Page-wide declarative import: Makes the class available anywhere in the view:

  <%!
  import tst.Customer
  %>
  

• Proper GSP page directive: If you prefer a JSP-like approach, ensure you use the full wrapper syntax:

  <%@ page import="tst.Customer" %>
  

Any of these options will fix the Unexpected input: '@ page import' error you encountered, as they align with Grails 5's GSP implementation rules.

内容的提问来源于stack exchange，提问作者Akram Esg