How to check for broken images in React JS

问题

I'm writing a module that takes article data from json and shows a large image over the article text, a hero module as they say.

I've got the data and have set it up so if there is an image, it will show that image and if there is no image in the data, it will show a default image. Problem is that this method doesn't replace broken links to show the default image.

I'm still new to react and using state ... question is, should I be using state to check for the broken link and how do I do it?

This is how I get the data in as props in the module:

const { newsItemData: {
          headline = '',
          bylines = [],
          publishedDate: publishDate = '',
          updatedDate: updatedDate = '',
          link: newsLink = '',
          contentClassification: category = '',
          abstract: previewText = '',
          abstractimage: { filename: newsImage = '' } = {},
          surfaceable: { feature: { type: featureType = '' } = {} } = {},
        } = {},
        wideView,
        showPill,
        defaultImage } = this.props;

I display the info in this way:

<div className={imageContainerClassName} style={customBackgroundStyles}>
      {newsImage ? <img className="img-responsive" src={newsImage} alt={headline}/> : <img className="img-responsive" src={defaultImage} alt={headline}/>}
</div>

What should I do in order to also check for broken images? I think this is all the pertinent data needed, let me know if I should show anything else. Thanks!

回答1:

There is a native event for images called onerror that lets perform an action if the image cannot be loaded.

<img onError={this.addDefaultSrc} className="img-responsive" src={newsImage} alt={headline}/>

//in your component
addDefaultSrc(ev){
  ev.target.src = 'some default image url'
}

回答2:

As mentioned, onError is the way to go.

If you're looking for a component that handles this for you, try https://github.com/socialtables/react-image-fallback

回答3:

According to my understanding you want to see broken images. you should call a method in onError attribute. Check this jQuery/JavaScript to replace broken images

来源：https://stackoverflow.com/questions/38527759/how-to-check-for-broken-images-in-react-js

标签

javascript

reactjs

error-handling

state