Adding an option to skip undefined urls

[ryan-talus]

Just found this plugin today, it's extremely helpful!

I hit this same issue: https://github.com/graysonhicks/gatsby-plugin-remote-images/issues/120

I'm using this plugin with another which creates a structure with a lot of null values so I've added a quick, minimal-changes fix.

This adds an option, skipUndefinedUrls, which short-circuits node creation where either the url passed to createImageNode() is falsy or the url returned from prepareUrl() (when defined) is falsy. This skips undefined urls and adds an easy way for the user to implement their own "undefined" values by returning undefined from the prepareUrl() function.

Example of using this change to set options to skip both null urls and urls which are 'N/A':

  plugins: [
    {
      resolve: `gatsby-plugin-remote-images`,
      options: {
        nodeType: 'MyRemoteNode',
        imagePath: 'data.imageUrl',
        // ** ALL OPTIONAL BELOW HERE: **
        skipUndefinedUrls: true,
        prepareUrl: (url: string) => {
          if (!url || url === 'N/A') return undefined
          return url
        },
      },
    },
  ]

Default behavior (without setting skipUndefinedUrls: true is unchanged so that the currently implemented errors aren't affected.

[graysonhicks]

Thanks @ryan-talus I'll test this out and merge it in!

[ryan-talus]

Thanks—let me know if I should change anything in the PR!

[colinrim]

Hi @graysonhicks Any update on this issue? Planed release to include this feature? Thanks

[graysonhicks]

Merged and released with 3.6.2, thanks!

[graysonhicks]

Oops, the changes on this PR were on the wrong gatsby-node file. Fixed and published as 3.6.3