我在 elasticsearch 之上使用 node.js 和 express.js 构建了一个应用程序。这是一个带有搜索框的非常简单的应用程序。当您搜索查询时，它会以 JSON 格式打印结果。例如，如果我搜索关键字“white”，输出如下所示:http://i.stack.imgur.com/VHuWl.png
现在我想将这个结果存储在一个文件中(例如 output.json)。这是我的 json 文件:
var fs = require('fs');
var path = "output.json";
var express = require('express'); //To make use of Express' routing capabilities you need to initiate a new Express Router.
var router = express.Router(); //To make use of Express' routing capabilities you need to initiate a new Express Router. get, put, post, delete, all
var searchModule = require('../search_module/search.js');
//There are two ways of using the router methods. You can define one route (for example /home) and attach the methods to it, or you can create a new method for each route.
/* GET home page. */
router.get('/', function(req, res) { //.get() - when you visit a website you make a GET request. You can get data from a URL in a GET request too.
res.render('index', { title: 'Express' });
});
router.post('/search-results', function(req, res) {//.post() is a method used everywhere for posting data to a server / app. You'll want to use this for submitting forms.
searchModule.search(req.body, function(data) {
res.render('index', { title: 'Express', results: data });
});
});
fs.writeFile(path,data,function(err){
if(err) console.error(err);
})
module.exports = router;
当我尝试使用 node.js 的 writeFile 方法时，我收到一个引用错误，显示“数据”未定义。我的错误如下所示:http://i.stack.imgur.com/lwXfW.png
我无法找出这个错误。有没有其他方法可以使用 node.js 和 express 将输出写入文件？
编辑:我编辑了我的 javascript
var fs = require('fs');
var path = "output.json";
var express = require('express'); //To make use of Express' routing capabilities you need to initiate a new Express Router.
var router = express.Router(); //To make use of Express' routing capabilities you need to initiate a new Express Router. get, put, post, delete, all
var searchModule = require('../search_module/search.js');
//There are two ways of using the router methods. You can define one route (for example /home) and attach the methods to it, or you can create a new method for each route.
/* GET home page. */
router.get('/', function(req, res) { //.get() - when you visit a website you make a GET request. You can get data from a URL in a GET request too.
res.render('index', { title: 'Express' });
});
router.post('/search-results', function(req, res) {//.post() is a method used everywhere for posting data to a server / app. You'll want to use this for submitting forms.
searchModule.search(req.body, function(data) {
fs.writeFile(path,data,function(err){
if(err) console.error(err);
})
res.render('index', { title: 'Express', results: data });
});
});
module.exports = router;
但是当我运行这个 javascript 时，我得到了这个输出: http://i.stack.imgur.com/rfBq0.png
我没有得到 JSON 输出。我的输出应如下所示:http://i.stack.imgur.com/VHuWl.png
我还在前端使用带有 javascript 的 ejs 文件 (index.ejs)，如下所示:
<!DOCTYPE html>
<html>
<head>
<title><%= title %></title>
</head>
<body>
<h1><%= title %></h1>
<form action='/search-results' method='post'>
<input type="text" name="searchTerm" placeholder="your search term here">
<button type="submit"> SEARCH </button>
</form>
<ul>
<% if(locals.results) { %>
<pre>
<%= JSON.stringify(results,null,2) %>
</pre>
<% results.forEach( function( result ) }) %>
<% } %>
</ul>
</body>
</html>
我需要从这个文件中获取输出吗？
最佳答案
此时未定义data 变量。
您可以像这样在 searchModule.search 调用中移动您的 fs.writeFile 函数:
searchModule.search(req.body, function(data) {
fs.writeFile(path,data,function(err){
if(err) console.error(err);
})
res.render('index', { title: 'Express', results: data });
});
或者之前声明你的变量并在 searchModule.search 调用中设置它，以便在写入你的文件的范围内之后不负责任:
var fileData;
searchModule.search(req.body, function(data) {
fileData = data;
res.render('index', { title: 'Express', results: data });
});
fs.writeFile(path,fileData,function(err){
if(err) console.error(err);
})
关于javascript - 如何使用 node.js 和 express 将结果写入文件？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37013532/