CODEWITHSUNDEEP
javascriptjqueryasp.netweb-servicesmime-types
user9538218
user9538218

Reputation:

Why text/plain downloading image types

I have a asp.net web service like as below for returning base 64: 

[WebMethod]
public string DownloadMediaFiles(string filePathUri, string fileName) {
 try {
  using(WebClient client = new WebClient()) {
   Byte[] bytes = client.DownloadData(filePathUri);
   string base64String = Convert.ToBase64String(bytes);
   return base64String;
  }
 } catch (Exception ex) {
  throw ex;
 }
}

And below is my ajax call: 

 $.ajax({
      type: 'POST',
      url: "Path To My Webservice" + "DownloadMediaFiles",
      data: {
        filePathUri: filePath,
        fileName: 'a.txt'
      },
      contentType: 'application/json;charset=uf=8',
      dataType: 'json',
      success: function(data) {
        var element = document.createElement('a');
        element.setAttribute('href', 'data:text/plain;base64,' +
          data.d);
        element.setAttribute('download', 'a.txt');
        element.style.display = 'none';
        document.body.appendChild(element);
        element.click();
        document.body.removeChild(element);
      },
      error: function() {
        alert("error");
      }
    });

It is working fine and downloading text file as I have set dataUri as data:text/plain;base64 but when I provide file name as 'pointing_2017_07_17_03_17_60.png' which is a image file then also it is downloading although datauri is set to text/plain.

Below is my html mark up for txt file as well as image file:

txt file:

<a href="data:text/plain;base64,certainbase64data" download="a.txt" style="display: none;"></a>

Image file:

<a href="data:text/plain;base64,certainbase64data" download="pointing_2017_07_17_03_17_60.png" style="display: none;"></a>

href="data:text/plain;base64 this attribute is downloading both text and image files.

I want to know why text/plain is downloading both image and text file?

Upvotes: 1

Views: 1755

Answers (1)

Kiran Shahi
Kiran Shahi

Reputation: 7970

text/plain is the default value for textual files. Even if it really means unknown textual file, browsers assume they can display it.

Note that text/plain does not mean any kind of textual data. If they expect a specific kind of textual data, they will likely not consider it a match. Specifically if they download a text/plain file from a element declaring a CSS files, they will not recognize it as a valid CSS files if presented with text/plain. The CSS mime type text/css must be used.

For more details: MIME types

So, your pointing_2017_07_17_03_17_60.png file is also treated as text file.

Upvotes: 1

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