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DIV onresize

The following example shows a simple implementation to track the changes in dimensions of a DIV using LemonadeJS.

Example

Tracking changes in a DIV dimensions example.

Source code

<html>
<script src="https://lemonadejs.com/v4/lemonade.js"></script>
<div id='root'></div>
<script>
function Width() {
    const self = this;

    self.init = function(element) {
        // Initial values
        var w = element.offsetWidth;
        var h = element.offsetHeight;

        // Track the changes
        element.onmousemove = function(e) {
            if (e.which) {
                if (w !== element.offsetWidth || h !== element.offsetHeight) {
                    w = element.offsetWidth;
                    h = element.offsetHeight;
                    self.onresize(element);

                    // Update dimensions label
                    self.dimensions = w + ',' + h;
                }
            }
        }
    }

    self.onresize = function(element) {
        console.log('DIV has new dimensions');
    }

    // Component template
    return `<div class="resizable" :ready="self.init">
        On resize on DIV elements: {{self.dimensions}}
    </div>`;
}
lemonade.render(Width, document.getElementById('root'));
</script>
</html>

import lemonade from 'lemonadejs';

export default function Width() {
    const self = this;

    self.init = function(element) {
        // Initial values
        var w = element.offsetWidth;
        var h = element.offsetHeight;

        // Track the changes
        element.onmousemove = function(e) {
            if (e.which) {
                if (w !== element.offsetWidth || h !== element.offsetHeight) {
                    w = element.offsetWidth;
                    h = element.offsetHeight;
                    self.onresize(element);

                    // Update dimensions label
                    self.dimensions = w + ',' + h;
                }
            }
        }
    }

    self.onresize = function(element) {
        console.log('DIV has new dimensions');
    }

    // Component template
    return `<div class="resizable" :ready="self.init">
        On resize on DIV elements: {{self.dimensions}}
    </div>`;
}

See this example on codesandbox

A pure vanilla implementation

Although this site is dedicated to LemonadeJS, for education purposes, we present you with a pure javascript vanilla implementation as follow.

DIV onresize example on jsfiddle

Source code

<html>
<script>
function move(e) {
    if ((e.w && e.w !== e.offsetWidth) || (e.h && e.h !== e.offsetHeight)) {
        new Function(e.getAttribute('onresize')).call(e);
    }
    e.w = e.offsetWidth;
    e.h = e.offsetHeight;
}
function resize() {
    console.log('Resized')
}
</script>
<div class='resizable' onresize="resize(this)" onmousemove="move(this)">
Pure vanilla implementation
</div>
</html>

The CSS used for this section

If you wish to test the examples of this section, please copy this CSS to your project.

.resizable {
    resize: both;
    overflow: auto;
    width: 200px;
    border: 1px solid black;
    padding: 20px;
}

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