vue-virtual-grid-btc

Vue Virtual Grid

Virtual Scrolling Grid made for VueJS based on CSS grids.

NPM Package | Demo Website

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• Render any Vue Component (images, iframes, content) of a known width/height inside.
• Variable height items in the same row and variable width items (based on columns).
• Highly customizable (custom loader, rendering, debug...).
• Rendering is done with virtual scrolling (aka windowing).
• Supports infinite scroll!

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Install

npm install --save vue-virtual-grid

Usage

Import VirtualGrid from the package:

import VirtualGrid from 'vue-virtual-grid';

Register it as on of your components:

components: {
    VirtualGrid,
},

In your template you can add:

<VirtualGrid :items="yourDataSet" :updateFunction="yourGetDataFunction" />

The items property is requeried and should be an array of the following object:

{
    id: string, // binding id (must be unique)
    injected?: string, // custom param, pass an object with what you want inside (optional)
    height: number, // original height of the item
    width?: number, // original width of the item (optional: if not set, height will not be adjusted by getItemRatioHeight)
    columnSpan: number, // how many columns will use your item (put 0 if you want the full width)
    newRow?: boolean, // if the item should appear on the next row (optional)
    renderComponent: Component // A VueJS component (custom template of your choice) to render the item (passed as prop `item`)
}

You can update the items property at any time (and thus decide what can of storage you want to use) and the grid layout will be recomputed.

Customizing the Grid

The VirtualGrid also takes multiple custom optional functions/variables as properties

• updateFunction: An async function that will populate the grid, constructor is the following updateFunction() => Promise<boolean>. For synchronous function just return immediately with Promise.resolve(boolean) for instance.
• getGridGap: A function that will define the gap between elements of the grid, constructor is the following getGridGap(elementWidth: number, windowHeight: number) => number.
• getColumnCount: A function that set the width of columns in the grid, constructor is the following getColumnCount(elementWidth: number) => number;.
• getWindowMargin: A function that set the margin size used for windowing (virtualization), constructor is the following getWindowMargin(windowHeight: number) => number;.
• getItemRatioHeight: A function that provides a way to adjust the item height by computing the initial height/width ratio and the column width (by default it preserves ratio), constructor is the following getItemRatioHeight(height: number, width: number, columnWidth: number) => number;.
• updateTriggerMargin: A number of pixels to the bottom of the page that will trigger the updateFunction.
• loader: A VueJS Component to display a loader when waiting for the next batch of data.
• debug: A boolean to activate debug log and monitor when batches are trigger and bottom reached for instance.

Properties are provided with default functions that you can use or get inspired from in src/utils.ts.

The function updateFunction should update the list of items that will be rendered (each item should look like the Item object presented before) and return (with a Promise) a boolean that signify that the last batch was loaded (bottom reached) or not.

The property injected does not impact the computation, it is here to pass custom data to the final component.

With default getItemRatioHeight, in the returned object to your renderComponent the height property will be recomputed depending on the column size and the width will be set to the column width multiplied by the column span of the item. Note that it will always keep the original ratio.

Important note: the component that will render the item should respect the returned height otherwise there will be a difference between computation and rendering (in other words, you will see glitches).

Last but not least, the resetGrid() method is exposed to parent in case you want to clear the grid :)

Passing events to the grid

The grid will pass any events attached to it to its children.

<VirtualGrid @custom-event="someMethod" />

That way, in your children Component, you can emit to this event and use the parent method.

this.$emit('custom-event', someArguments);

On the demo you can try this by clicking on a section title, it will display an alert box from the parent component.

Typescript support

If you're using Typescript you can import typing for Item and provide custom typing for injected data:

import { Item } from 'vue-virtual-grid';

interface Image {
    alt: string;
    url: string;
}

const item: Item<Image>;

You can also import the typing for utils methods with VirtualGridInterface.

Live example

If you want a live example, you can take a look at the demo (link at the top) and check the corresponding code in example/.

Contribute

Anyone is welcome to contribute (this project is not perfect obviously).

Install current dependencies

npm ci

Build and try the example

npm run serve:example

Compiles lib for production

npm run build

Lints and fixes files

npm run lint

Inspiration

This is based on React work here: https://github.com/jamiebuilds/react-gridlist

Kudos to Jamie!

Maintainer

Corentin Mors