将Google图表另存为图片

Question

So after hours of websearching, googling and overflowing i can't find the solution to my problem.

I got a linechart from Google charts. I want to convert it to PNG, save it on the server en insert it into a MySQL database.

Sounds simple, but i cant get it to work. The script from this website isnt working anymore (atleast not here) http://www.battlehorse.net/page/topics/charts/save_google_charts_as_image.html -> Not working.

Second option is the old option:

$imageData =     file_get_contents('http://chart.apis.google.com/chart... etc');

I cant use that because its not supported anymore and cant get some decent quality out of it.

Is there anybody here that can give a good tutorial or help for my problem?

EDIT:

I used the code from Battlehorse combined with the code from EriC.

So now i got this working to show the chart as an image in a DIV i want to save this image on the server and update the mysql to use it in the future to use it in PDF files.

Answer 1

When you visit the site, paste this in the console (overwriting the malfunctioning function).

  function getImgData(chartContainer) {
    var chartArea = chartContainer.getElementsByTagName('svg')[0].parentNode;
    var svg = chartArea.innerHTML;
    var doc = chartContainer.ownerDocument;
    var canvas = doc.createElement('canvas');
    canvas.setAttribute('width', chartArea.offsetWidth);
    canvas.setAttribute('height', chartArea.offsetHeight);


    canvas.setAttribute(
        'style',
        'position: absolute; ' +
        'top: ' + (-chartArea.offsetHeight * 2) + 'px;' +
        'left: ' + (-chartArea.offsetWidth * 2) + 'px;');
    doc.body.appendChild(canvas);
    canvg(canvas, svg);
    var imgData = canvas.toDataURL("image/png");
    canvas.parentNode.removeChild(canvas);
    return imgData;
  }

In JS it was searching for an iframe bla bla to get the svg.

To automatically save the image, you can just let the method being invoked programmatically.

document.body.addEventListener("load", function() {

        saveAsImg( document.getElementById("pie_div")); // or your ID

    }, false );

For saving images serverside, this post could be helpful save a PNG image server-side

Update
Posting images to PHP (index.js)

function saveToPHP( imgdata ) {

    var script = document.createElement("SCRIPT");

    script.setAttribute( 'type', 'text/javascript' );
    script.setAttribute( 'src', 'save.php?data=' + imgdata );

    document.head.appendChild( script );
}

function save() {

    var canvas = document.getElementById("canvas"), // Get your canvas
        imgdata = canvas.toDataURL();

    saveToPHP( imgdata );
}

function drawOnCanvas() {

    var canvas = document.getElementById("canvas"), // Get your canvas
        ctx = canvas.getContext("2d");

    ctx.strokeStyle = "#000000";
    ctx.fillStyle = "#FFFF00";
    ctx.beginPath();
    ctx.arc(100,99,50,0,Math.PI*2,true);
    ctx.closePath();
    ctx.stroke();
    ctx.fill();
}

drawOnCanvas(); // Test
save();

save.php

<?php
    // Get the request
    $data = $_GET['data'];

    // Save to your DB.
?>