Sending generated canvas image to website server?

Question

I'm in the developmental stage of my custom cup eCommerce site. I am working on a personalization feature so my customers can design their own cup. Everything is about finished. I can preview, print, and export the canvas image, as seen here: https://metaldepot.americommerce.com/Designer/index.html When clicking the export button, the image can be generated and downloaded to the users computer . However, I'd like the canvas image to be generated and uploaded to my website server . Here is the coding I have so far for the export button in my index.html file and my app.js file

app.js:

  // export as DESIGN

  $('.export').click(function(){
    //hide options
    $('#printable').find('i').css('display', 'none');
    $('#printable').find('.ui-icon').css('display', 'none');
    //get printable section
    var exportCanvas = document.getElementById('printable');
    //get convas container
    var canvasContainer = document.getElementById('convascontent');
    //export canvas to convascontainer
    html2canvas(exportCanvas, {
      //when finished fucntion
      onrendered: function(canvas) {
        // initialize canvas container (if we generate another canvas)
        $('#convascontent').html(' ');
        // append canvas to container
        canvasContainer.appendChild(canvas);
        //add id attribute to the canvas
        $('#convascontent').find('canvas').attr('id','mycanvas');
        // display options again
        $('#printable').find('i').css('display', 'block');
        $('#printable').find('.ui-icon').css('display', 'block');
        //document.getElementsByTagName("UL")

      }
    });
    // return false;
  });

  //export options
  $('.exportas').click(function(){
    // get type to export
    var to = $(this).data('type');
    // alert(to);
    // get our canvas
    var oCanvas = document.getElementById("mycanvas");  
    // support variable
    var bRes = false;
    if(to == 'png'){
      // export to png 
      bRes = Canvas2Image.saveAsPNG(oCanvas);
    }
    if(to == 'jpg'){
      // maybe in some old browsers it works only on Firefox
      bRes = Canvas2Image.saveAsJPEG(oCanvas);
    }if(to == 'bmp'){
      Res = Canvas2Image.saveAsBMP(oCanvas);
    }
    // if browser doesn't support mimetype alert user
    if (!bRes) {
      alert("Sorry, this browser is not capable of saving " + strType + " files!");
      return false;
    }
  });

index.html

 <!-- export option (png, jpg, bmp) -->
            <li>
              <div class="btn-group dropup">
                <a class="dropdown-toggle export btn" data-toggle="dropdown" href="#">
                  Export
                  <span class="caret"></span>
                </a>

                <ul class="dropdown-menu">
                  <li>
                    <a href="#" class="exportas" data-type='png'>PNG</a>
                    <a href="#" class="exportas" data-type='jpg'>JPG</a>
                    <a href="#" class="exportas" data-type='bmp'>BMP</a>

Any help would be greatly appreciated, thank you for your time!

Answer 1

You can get contents, and send via ajax to server.

  $('.save').click(function(){
    // get our canvas
    var oCanvas = document.getElementById("mycanvas");  
    var data = oCanvas.toDataURL(); // default png
    // var data = oCanvas.toDataURL('image/jpeg'); // for jpg 

    $.post('/url_to_upload', { customer : 'id', data : data });
  });

now, server side - posted vars contains data like

"data:image/png;base64,/9j/4AAQS....."

split with first comma ',' , and decode base64. then save to DB or FS or.. anywhere you want.