How to bring to you this timeUsing JavaScript to save text data, what are the precautions for using JavaScript to save text data, the following is a practical case, let's take a look.
JavaScript save text data example, of course not only text but other types are also possible
First code
<!DOCTYPE html><html>
<head>
<meta charset="UTF-8">
<title></title>
<script>
var fl; function g(f) {
fl = null; if(f) { document.getElementById("fname").innerText = f.name; document.getElementById("fsize").innerText = f.size;
fl = f;
}
} function dataURLSave1() { if(fl) { var reader = new FileReader();
reader.onload = function(e) {
ck(e.target.result);
};
reader.readAsDataURL(fl);
}
} function dataURLSave2() { if(fl) { var reader = new FileReader();
reader.onload = function(e) {
ck('data:text/plain;charset=utf-8,' + e.target.result);
};
reader.readAsText(fl);
}
} function objectURLSave() { if(fl) {
ck(URL.createObjectURL(fl));
setTimeout(function(){
URL.revokeObjectURL(fl);//用URL.revokeObjectURL()来释放这个object URL
},200);
}
} function ck(href) { document.getElementById("hf").href = href; document.getElementById("hf").download = fl.name; document.getElementById("hf").click();
} </script>
</head>
<body>
<input type="file" onchange="g(this.files[0])">
<div>文件名:<span id="fname"></span></div>
<div>大小:<span id="fsize"></span></div>
<button onclick="dataURLSave1()">保存(dataURL方式1)</button>
<button onclick="dataURLSave2()">保存(dataURL方式2)</button>
<button onclick="objectURLSave()">保存(objectURLSave方式)</button>
<a id="hf" href="" download="download"></a>
</body></html>implement classification
Generally Using the browser's built-in function to export text files can be simply divided into two methods
1.DataURL
2.ObjectURL
Principle
In fact, the principle is the same as usual downloading are the same, except that the download link is replaced by the above two URLs
Comparison
DataURL method
In the sample code, DataURL method 1 is to directly copy the text file Read into DataURL, DataURL method 2 is to read the text content and then splice the content with (data:text/plain;charset=utf-8,...)
DataURL method 1 and DataURL method 2 pair the file text Encoding has certain requirements and is prone to garbled characters
ObjectURL method
ObjectURL converts objects in memory into ObjectURL. Compared with DataURL, ObjectURL is less prone to garbled characters, but DataURL is relatively fixed compared to ObjectURL Unfixed
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!
Related reading:
How to write a simulator with JS
set data structure and map data of ES6 Structure
#Detailed explanation of the new array API in ES6
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