Question

我有一个函数可以执行某些逻辑，然后运行成功回调函数或失败回调函数。

以下是代码：

package com.demo.search.repository;

import com.demo.model.Book;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.notNullValue;
import static org.junit.Assert.assertThat;

    /**
     * Test things on {@link BookSearchRepository}
     */
    @RunWith(SpringJUnit4ClassRunner.class)
    @SpringBootTest
    public class BookSearchRepositoryTest {

        @Autowired
        private BookSearchRepository bookRepository;

        @Autowired
        private ElasticsearchTemplate elasticsearchTemplate;

        @Before
        public void before() {

            elasticsearchTemplate.deleteIndex(Book.class);
            elasticsearchTemplate.createIndex(Book.class);
            elasticsearchTemplate.putMapping(Book.class);
            elasticsearchTemplate.refresh(Book.class);
        }

        @Test
        public void shouldSaveBook(){

            Book book = new Book();
            book.setBookId("1");
            book.setTitle("Learning Scala");

            Book indexedBook = bookRepository.save(book);

            assertThat(indexedBook, is(notNullValue()));
            assertThat(indexedBook.getBookId(), is(book.getBookId()));
            assertThat(bookRepository.findOne("1"), is(notNullValue()));
        }
    }

如何将some_function() -> ArgumentsForCallback = [], check_some_condition(Input, fun success_callback/1, fun fail_callback/1).传递给回调？

Answer 1

有两种方法：

将参数传递给check_some_condition并使该函数将参数发送给回调：

check_some_condition(Input, ArgumentsForCallback, Success, Fail) ->
    Success(ArgumentsForCallback).

some_function() ->
    ArgumentsForCallback = [],
    check_some_condition(Input, ArgumentsForCallback, fun success_callback/1, fun fail_callback/1).

将匿名函数发送到check_some_condition：

check_some_condition(Input,
    fun() -> success_callback(ArgumentsForCallback) end,
    fun() -> fail_callback(ArgumentsForCallback) end).

如何将参数传递给Erlang中的回调？

1 个答案: