React-container-dimensions NPM

react-container-dimensions

Wrapper component that detects parent (container) element resize and passes new dimensions down the tree. Based on element-resize-detector.

npm install --save react-container-dimensions

It is especially useful when you create components with dimensions that change over time and you want to explicitely pass the container dimensions to the children. For example, SVG visualization needs to be updated in order to fit into container.

It uses getBoundingClientRect() and passes values for all top, right, bottom, left, width, height CSs attributes down the tree.

Usage

Wrap your existing components. Children component will recieve top, right, bottom, left, width, height as props.

<ContainerDimensions>
    <MyComponent/>
</ContainerDimensions>

Use a function to pass width or height explicitely or do some calculation. Function callback will be called with an object { width: number, height: number } as an argument and it expects the output to be a React Component or an element.

<ContainerDimensions>
    { ({ height }) => <MyComponent height={height}/> }
</ContainerDimensions>

How is it different from similar_component_here

It does not create a new element in the DOM but relies on the parentNode which must be present. So, basically, it acts as a middleware to pass the dimensions of your styled component to your children components. This makes it very easy to integrate with your existing code base.

For example, if your parent container has display: flex, only adjacent children will be affected by this rule. This means if your children rely on flex CSS property, you can't wrap it in a div anymore since this will break the flexbox flow.

So this won't work anymore:

<div style="display: flex">
    <div>
        <div style="flex: 1">...</div>
    </div>
</div>

react-container-dimensions doesn't change the resulting HTML markup, so it remains:

<div style="display: flex">
    <div style="flex: 1">...</div>
</div>

Example

Let's say you want your SVG visualization to always fit into the container. In order for SVG to scale elements properly it is required that width and height attributes are properly set on the svg element. Imagine the following example

Before (static)

It's hard to keep dimensions of the container and the SVG in sync. Especially, when you want your content to be resplonsive (or dynamic).

export const myVis = () => (
    <div className="myStyles">
        <svg width={600} height={400}>
            {/* SVG contents */}
        </svg>  
    <div>
)

After (dynamic)

This will resize and re-render the SVG each time the div dimensions are changed. For instance, when you change CSS for .myStyles.

import ContainerDimensions from 'react-container-dimensions'

export const myVis = () => (
    <div className="myStyles">
        <ContainerDimensions>
            { ({ width, height }) => 
                <svg width={width} height={height}>
                    {/* SVG contents */}
                </svg>  
            }
        </ContainerDimensions>
    <div>
)