Using DataTables and Buttons (NOT TableTools, which is retired) extension. Some cells have progressbars and small icons. Is there a way to export these images (or at least their titles) to PDF? Found some possible hacks on this page, but all of them were for retired TableTools.
Checked https://datatables.net/reference/button/pdf and https://datatables.net/reference/api/buttons.exportData%28%29 but couldn't find any method to achieve this goal. Tested by adding this code:
stripHtml: false
but whole HTML code (like img src=...) was included in PDF file instead of images.
If exporting images isn't possible, is there a way to export at least alt or title attribute of each image? That would be enough.
I assume you are using pdfHtml5. dataTables is using pdfmake in order to export pdf files. When pdfmake is used from within a browser it needs images to be defined as base64 encoded dataurls.
Example : You have rendered a <img src="myglyph.png">
in the first column of some of the rows - those glyphs should be included in the PDF. First create an Image
reference to the glyph :
var myGlyph = new Image();
myGlyph.src = 'myglyph.png';
In your customize
function you must now
1) build a dictionary with all images that should be included in the PDF
2) replace text
nodes with image
nodes to reference images
buttons : [
{
extend : 'pdfHtml5',
customize: function(doc) {
//ensure doc.images exists
doc.images = doc.images || {};
//build dictionary
doc.images['myGlyph'] = getBase64Image(myGlyph);
//..add more images[xyz]=anotherDataUrl here
//when the content is <img src="myglyph.png">
//remove the text node and insert an image node
for (var i=1;i<doc.content[1].table.body.length;i++) {
if (doc.content[1].table.body[i][0].text == '<img src="myglyph.png">') {
delete doc.content[1].table.body[i][0].text;
doc.content[1].table.body[i][0].image = 'myGlyph';
}
}
},
exportOptions : {
stripHtml: false
}
}
Here is a an example of a getBase64Image
function
function getBase64Image(img) {
var canvas = document.createElement("canvas");
canvas.width = img.width;
canvas.height = img.height;
var ctx = canvas.getContext("2d");
ctx.drawImage(img, 0, 0);
return canvas.toDataURL("image/png");
}
If you just want to show the title
of images in the PDF - or in any other way want to manipulate the text content of the PDF - then it is a little bit easier. The content of each column in each row can be formatted through the exportOptions.format.body
callback :
buttons : [
{
extend : 'pdfHtml5',
exportOptions : {
stripHtml: false
format: {
body: function(data, col, row) {
var isImg = ~data.toLowerCase().indexOf('img') ? $(data).is('img') : false;
if (isImg) {
return $(data).attr('title');
}
return data;
}
}
}
]
The reason format.body
cannot be used along with images is that is only let us pass data back to the text
node part of the PDF document.
See also