[英]500 TypeError: Cannot read property 'name' of undefined WHILE transferring data from html form to Node js server?
我正在嘗試將數據從html頁面發送到NodeJS服務器。
我的html代碼是：
<body>
<nav>
<ul>
<li>
<a href="#" class="button add">Add Product</a>
<div class="dialog" style="display:none">
<div class="title">Add Product</div>
<form action="addevent" method="get">
<input id = "name" name="name" type="text" placeholder="Product Name"/>
<input name="code" type="text" placeholder="Product Code"/>
<input name="category" type="text" placeholder=" Category"/>
<input name="brand" type="text" placeholder="Brand"/>
<input type="submit" value="Ok"/>
</form>
</div>
</li>
<li class="radio">
<a href="#" class="button active"></a>
<a href="#" class="button"></a>
<a href="#" class="button"></a>
</li>
</ul>
</div>
</nav>
<p></p>
<script src='http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js'></script>
<script src="js/index.js"></script>
</body>
我的服務器代碼是：
server.js
var express = require("express"),
app = express(),
bodyParser = require('body-parser'),
errorHandler = require('errorhandler'),
methodOverride = require('method-override'),
hostname = process.env.HOSTNAME || 'localhost',
port = parseInt(process.env.PORT, 10) || 4004,
publicDir = process.argv[2] || __dirname + '/public';
var exec = require('child_process').exec;
var fs = require('fs');
//Show homepage
app.get("/", function (req, res) {
res.redirect("/index.html");
});
app.get("/addevent", function (req, res){
res.send('You sent the name "' + req.body.name + '".');
});
//Search page
app.use(methodOverride());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: true
}));
app.use(express.static(publicDir));
app.use(errorHandler({
dumpExceptions: true,
showStack: true
}));
console.log("Server showing %s listening at http://%s:%s", publicDir, hostname, port);
app.listen(port);
但是當我從html頁面提交表單時，它給出了以下錯誤！
Connect 500 TypeError: Cannot read property 'name' of undefined at app.use.bodyParser.urlencoded.extended (/home/shubham/Music/pricesync/server/server.js:17:45) at Layer.handle [as handle_request] (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/layer.js:95:5) at next (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/route.js:131:13) at Route.dispatch (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/route.js:112:3) at Layer.handle [as handle_request] (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/layer.js:95:5) at /home/shubham/Music/pricesync/server/node_modules/express/lib/router/index.js:277:22 at Function.process_params (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/index.js:330:12) at next (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/index.js:271:10) at expressInit (/home/shubham/Music/pricesync/server/node_modules/express/lib/middleware/init.js:33:5) at Layer.handle [as handle_request] (/home/shubham/Music/pricesync/server/node_modules/express/lib/router/layer.js:95:5)
在GET HTTP請求中，沒有req.body ，這就是未定義錯誤的原因。 表單字段的值將作為查詢字符串傳遞，因此您需要從req對象讀取查詢字符串值。
嘗試將路由置於中間件下方，並使用“ POST” http動詞。
var express = require("express"),
app = express(),
bodyParser = require('body-parser'),
errorHandler = require('errorhandler'),
methodOverride = require('method-override'),
hostname = process.env.HOSTNAME || 'localhost',
port = parseInt(process.env.PORT, 10) || 4004,
publicDir = process.argv[2] || __dirname + '/public';
var exec = require('child_process').exec;
var fs = require('fs');
//Search page
app.use(methodOverride());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: true
}));
app.use(express.static(publicDir));
//Show homepage
app.get("/", function (req, res) {
res.redirect("/index.html");
});
app.post("/addevent", function (req, res){
res.send('You sent the name "' + req.body.name + '".');
});
app.use(errorHandler({
dumpExceptions: true,
showStack: true
}));
console.log("Server showing %s listening at http://%s:%s", publicDir, hostname, port);
app.listen(port);
確保將表單方法也更改為“ post”。
為了將數據從HTML表單發送到服務器，最佳實踐是使用POST方法。 表單提交的默認編碼為：
內容類型：應用程序/ x-www-form-urlencoded
在Express中，您已將bodyParser中間件與json（）方法一起使用，該方法不起作用，因為您發送的數據不是JSON編碼的。
您的bodyParser必須像這樣在您的路線之前：
app.use(bodyParser.urlEncoded());
app.post("/addevent", function (req, res){
....
我建議您閱讀初學者的書
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