Copyright dog retreats - Copying text from Zhihu comes with its own copyright statement.

What the hell?#

Similar to Zhihu, when copying text longer than 42 characters on the website, automatically add such a copyright statement:

Copyright belongs to the author.
For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source.
Author: DIYgod
Link: https://www.anotherhome.net/
Source: Anotherhome

Principle#

Listen for copy events
Use window.getSelection() to get the selected text
Use clipboardData.setData to manipulate the content of the clipboard

Code#

document.body.addEventListener('copy', function (e) {
    if (window.getSelection().toString() && window.getSelection().toString().length > 42) {
        setClipboardText(e);
        alert('For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source. Thank you for your cooperation.');
    }
});

function setClipboardText(event) {
    var clipboardData = event.clipboardData || window.clipboardData;
    if (clipboardData) {
        event.preventDefault();

        var htmlData = ''
            + 'Copyright belongs to the author.&lt;br&gt;'
            + 'For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source.&lt;br&gt;'
            + 'Author: DIYgod&lt;br&gt;'
            + 'Link: ' + window.location.href + '&lt;br&gt;'
            + 'Source: Anotherhome&lt;br&gt;&lt;br&gt;'
            + window.getSelection().toString();
        var textData = ''
            + 'Copyright belongs to the author.\n'
            + 'For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source.\n'
            + 'Author: DIYgod\n'
            + 'Link: ' + window.location.href + '\n'
            + 'Source: Anotherhome\n\n'
            + window.getSelection().toString();

        clipboardData.setData('text/html', htmlData);
        clipboardData.setData('text/plain',textData);
    }
}

Known Issues#

iOS Safari is not compatible with the clipboardData.setData() method, so it is ineffective on iOS Safari.

Zhihu Original Version#

The following is the key code of the original version on Zhihu. The principle is similar, you can also take a look if you are interested:

var lz = function (a, b, c) {
    function d(a, b) {
        return ["Copyright belongs to the author.", "For commercial reprint, please contact the author for authorization. For non-commercial reprint, please indicate the source.", "Author: " + b, "Link: " + a, "Source: Zhihu", "", ""]
    }

    function f(a, b, c) {
        return "\x3cdiv\x3e" + d(b, c).join("\x3cbr /\x3e") + a + "\x3c/div\x3e"
    }

    function g(a) {
        var g = z.Wq(), m = g && (0, z.ib)(g.Ed());
        if (m && !(42 > m.length)) {
            if ("object" === typeof a.originalEvent.clipboardData && (a.originalEvent.clipboardData.setData("text/html", f(g.Of(), b, c)), a.originalEvent.clipboardData.setData("text/plain", d(b, c).join("\n") + m), 0 < a.originalEvent.clipboardData.getData("text/plain").length)) {
                a.preventDefault();
                return
            }
            if (window.getSelection) {
                a = g.Of();
                var n = (0, window.$)(f(a, b, c)).css({position: "fixed", left: "-9999px"}).appendTo("body");
                window.getSelection().selectAllChildren(n.get(0));
                (0, window.setTimeout)(function () {
                    g.select();
                    n.remove()
                }, 200)
            }
        }
    }

    a && b && c && (z.Fa(b, "http") || (b = window.location.protocol + "//" + window.location.host + b), a.on("copy", g))
};