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rams502/postcanvas.js

Forked from hnagata/postcanvas.js
Created August 8, 2017 11:19
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  1. @hnagata hnagata created this gist Mar 11, 2014.
    28 changes: 28 additions & 0 deletions postcanvas.js
    View file
    Original file line number Diff line number Diff line change
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    /*
    * Code snippet to post a HTML5 Canvas image to Facebook
    * H. Nagata
    *
    * Variables:
    * accessToken: Facebook access token
    * targetID: Posting target id such as user id or album id
    * canvas: HTMLCanvasElement
    * base64.decode: c.f. https://github.com/hnagata/js-base64
    *
    * It won't work in IE9 since using ArrayBuffer/FormData/Blob.
    */

    // Convert canvas into binary data
    var data_url = canvas.toDataURL();
    var mime = data_url.slice(data_url.indexOf(":") + 1, data_url.indexOf(";"));
    var data = base64.decode(data_url.slice(data_url.indexOf(",") + 1));

    // Construct FormData
    var fd = new FormData();
    fd.append("access_token", accessToken);
    fd.append("source", new Blob([data], {type: mime}));
    // And append some fields, such as "message" and "privacy"

    // POST
    var req = new XMLHttpRequest();
    req.open("POST", "https://graph.facebook.com/" + targetID + "/photos");
    req.send(fd);