jb-image-input

jb-image-input

image input web component let user upload image and see what is uploaded

• ability multiple image upload

• can connect to your custom REST service bridge (you can have your own way of uploading image)

• show loading

• can be used in both instant upload or keep image and upload image on form submit

• customizable format

sample: https://codepen.io/javadbat/pen/XWpoEYY

using with JS frameworks

to use this component in react see jb-image-input/react;

instruction

usage

npm i jb-image-input

<jb-image-input></jb-image-input>

current status

you can access current image input status by element.status

check validation

jb-image-input use jb-validation inside to handle validation. so for more information you can read jb-validation documentation. by set required and maxFileSize you can easily have these 2 validation but for more advanced validation functions you can provide your own validation function list

imageInput.validation.list = [
        {
            validator: ({file})=>{return file.size < 500 * 1024},
            message: 'your file size must be above 500KB'
        },
    ];
//check and show validations by simple calling the function (pass false if you dont want to show error and just want to check silently)
const result = imageInput.validation.checkValidation(true);

multi image selector

by default jb-image-input don't support multi image upload but in set of hack you can implement a system that user can select and upload multiple image we have 4 step to help you implement multi image input

1- set multiple attribute to dom to let user select multiple image

<jb-image-input multiple="true">

2- imageSelected event is fired on user select image and in event.detail.filesyou can get all files that user selected 3- create new <jb-image-input> dom by js with document.createElement('jb-image-input') 4- inject the files you get in step 2 into your component by a selectImageByFile function

document.querySelector('jb-image-input').addEventListener('imageSelected',function(e){
    const files = e.detail.files;
    if (files.length > 1) {
            for (let i = 1; i < files.length; i++) {
                document.querySelectorAll('jb-image-input')[i].selectImageByFile(files[i])
            }
            this.addImageInput();
        }
    
});

remember first file is uploaded by original image input and you don't need to inject it to another input and thats why we start from index 1

image accept type

tell web-component what image mimetype are acceptable

 document.querySelectorAll('jb-image-input').acceptTypes = "image/jpeg,image/jpg,image/png,image/svg+xml"

set bridge for upload and download image

jb-image-input do not upload and download image automatically. it just handle ui states. you must provide 2 function uploader and downloader to component like this:

document.querySelectorAll('jb-image-input').bridge = {
            uploader: function (file,config,uploadProgressCallbackFunction) { /*put your functionality here*/},
            downloader: function (value, config) { /*put your functionality here*/}
        };

you can create a class and pass class instance or create a simple object and pass it to component, depend on your need. both uploader and downloader must return Promise and resolve it on task completed

argumant variable name	description
file	the file that user select from his computer
config	the config developer provided to component. most of the times projects has a one bridge instance for many image input so in this case you build only one bridge and pass it to all of your components and pass parameter like url, method , fieldName, ... in config so your bridge can decide how to upload and download app
uploadProgressCallbackFunction	its a optional parameter you can use to tell component how much file uploaded currently
value	value is a data that your uploader promise resolved for example if your uploader is: uploader:()=>{upload().then(()=>{resolve({fileName:'img.jpg',path:'x.com/img.jpg',id:'10'})})} then your value wil be {fileName:'img.jpg',path:'x.com/img.jpg',id:'10'}

set config

config is not something that our component use, it just the config you need in your bridge so you can set it however you want base on your need. we just keep it in component and send it to your uploader and downloader function so you can structure it your self. we just make a default structure as following object

this.config = {
            uploadUrl: '',
            downloadUrl: '',
            // developer can add every config he want's to get on bridge functions
        };

custom placeholder

if you want to show your custom content when uploader is empty and ready to receive image in first place ypo can put your own content by using custom slot. to make that happen you just have to put your div and content in jb-image-input tag like below example:

<jb-image-input>
    <div slot="placeholder">
            <div>custom placeholder</div>
    </div>
</jb-image-input>

you can place any element you need base on you design in <div slot="placeholder"> you can use anything other than div too for example <h1 slot="placeholder"> but you must set attribute slot="placeholder" in it.

max File Size

you can set max for user file size so user cant upload file larger than your limit. to do so just set maxFileSize like following example:

//set max file size to 2MB
document.querySelector('jb-image-input').maxFileSize = 2*1024*1024;

when user select file bigger than that image input will dispatch(fire) the maxSizeExceed event.

//set max file size to 2MB
document.querySelector('jb-image-input').addEventListener('maxSizeExceed',(e)=>{
    alert(`your file is ${e.detail.file.size} size and it's bigger than 2MB`);
});

set custom style

in some cases in your project you need to change default style of web-component for example you need zero margin or different border-radius and etc.
if you want to set a custom style to this web-component all you need is to set css variable in parent scope of web-component

css variable name	description
--jb-image-input-width	web-component width default is 100%
--jb-image-input-height	web-component height default is 100%
--jb-image-input-bg-color	web-component background-color default is #f7f6f6
--jb-image-input-border-radius	web-component border radius default is 24px
--jb-image-input-placeholder-p-color	web-component placeholder icon primary color
--jb-image-input-placeholder-bg-color	web-component placeholder background-color default is transparent
--jb-image-input-placeholder-sec-color	placeholder secondary color

Other Related Docs:

• see jb-image-input/react if you want to use this component in react.

• see All JB Design system Component List for more components.

• use Contribution Guide if you want to contribute in this component.