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[英]'Uncaught SyntaxError: Unexpected token <' in Node.js
[英]Uncaught SyntaxError: Unexpected token var Node.js
我正在使用Node.js,並試圖顯示圖表,該圖表是根據txt文件的坐標生成的,並已上傳到服務器。 我的問題:打開網頁並上傳文件時,一切正常,但是圖表卻無法正常工作:我收到以下錯誤: UncaughtSyntaxError:意外的令牌var。
如果我在不使用node.js的情況下呈現網頁,則一切正常。
編碼:
var express = require("express");
var app = express();
var fs = require('fs'); // we will need it for file uploads
var port = process.env.PORT || 3000;
app.configure(function(){
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(__dirname + '/public'));
});
app.get('/', function(req, res) {
res.send('<form method="post" enctype="multipart/form-data">'
+ '<p>Image: <input type="file" name="uploadfile" /></p>'
+ '<p><input type="submit" value="Upload" /></p>'
+ '</form>');
});
app.post('/', function(req, res){
// .. Upload and file reading
// .. var obj[key1] (X-Values) and var obj[key2] (Y-Values) are generated
// ..
res.send('<head><title>Line Chart</title><script src="../Chart.js"></script><meta name = "viewport" content = "initial-scale = 1, user-scalable = no"><style>canvas{ }</style></head><body><canvas id="canvas" height="450" width="600"></canvas>'
+'<script type="text/javascript">'
+' '
+'var lineChartData = { '
+'labels : [ ' + obj[key1] + ' ],'
+'datasets : [{'
+'fillColor : "rgba(151,187,205,0.5)",'
+'strokeColor : "rgba(0, 0, 0, 0.831373)",'
+'pointColor : "rgba(151,187,205,1)",'
+'pointStrokeColor : "gba(76, 255, 178, 0.831373)",'
+'data : ['+ obj[key2] + ' ]'
+'} ] } '
+'var myLine = new Chart(document.getElementById("canvas").getContext("2d")).Line(lineChartData);'
+'</script>'
+'</body></html>'
);
};
});
});
});
app.listen(port, function() {
console.log("Listening on " + port);
});
我希望你能幫幫我..
問候,
JS
由於您不在代碼示例中使用換行符,因此將輸出:
var lineChartData = { labels : [ undefined ],datasets : [{fillColor : "rgba(151,187,205,0.5)",strokeColor : "rgba(0, 0, 0, 0.831373)",pointColor : "rgba(151,187,205,1)",pointStrokeColor : "gba(76, 255, 178, 0.831373)",data : [undefined ]} ] } var myLine = new Chart(document.getElementById("canvas").getContext("2d")).Line(lineChartData);
這是無效的Javascript,因為您需要使用;來關閉'lineChardData'對象。
將其更改為此,它將起作用:
res.send('<head><title>Line Chart</title><script src="../Chart.js"></script><meta name = "viewport" content = "initial-scale = 1, user-scalable = no"><style>canvas{ }</style></head><body><canvas id="canvas" height="450" width="600"></canvas>'
+'<script type="text/javascript">'
+' '
+'var lineChartData = { '
+'labels : [ ' + obj[key1] + ' ],'
+'datasets : [{'
+'fillColor : "rgba(151,187,205,0.5)",'
+'strokeColor : "rgba(0, 0, 0, 0.831373)",'
+'pointColor : "rgba(151,187,205,1)",'
+'pointStrokeColor : "gba(76, 255, 178, 0.831373)",'
+'data : ['+ obj[key2] + ' ]'
+'} ] }; '
+'var myLine = new Chart(document.getElementById("canvas").getContext("2d")).Line(lineChartData);'
+'</script>'
+'</body></html>'
);
同樣,我也不認為以這種方式直接從Node.js輸出HTML / javascript數據是一個好方法。
您沒有發送任何換行符,因此(已精簡)JavaScript解釋器會看到以下無效代碼:
var lineChartData = { /*...*/} var myLine = new Chart(/*...*/);
在第一個var
語句之后放一個分號,它將起作用:
var lineChartData = { /*...*/}; var myLine = new Chart(/*...*/);
// ^ Put me here
如果輸出中出現換行符,則可以像ASI那樣使用分號來工作,因此這是另一種可能的解決方案。
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