💾 gatsby-plugin-remote-images

Download images from any string field on another node so that those images can
be queried with gatsby-plugin-image.

- Usage
- Install
- Options -
Example Config with Optional Options
- Why?
- Common Issues

- gatsby-source-graphql
- Traversing objects with arrays
- Handling an Array of Image URLs

Note: This plugin support gatsby-plugin-image and drops support for
gatsby-image in 3.0.0.

Usage

$3

First, install the plugin.

npm install --save gatsby-plugin-remote-images

Second, set up the gatsby-config.js with the plugin. The most common config
would be this:

``javascript
module.exports = {
plugins: [
{
resolve: gatsby-plugin-remote-images,
options: {
nodeType: 'MyNodes',
imagePath: 'path.to.image',
},
},
],
};
`

$3

| Option Name | Description | Required | Default |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------- | ------------ |
| nodeType | The node type that has the images you want to grab. This is generally the title-cased version of the word after the 'all' in GraphQL ie. allMyImages type is MyImages | ✅ | null |
| imagePath | For simple object traversal, this is the string path to the image you want to use, relative to the node. This uses lodash .get, see docs for accepted formats here. For traversing objects with arrays at given depths, see how to handle arrays along the path below. | ✅ | null |
| name | Name you want to give new image field on the node. Defaults to localImage. | ❌ | localImage |
| auth | Adds htaccess authentication to the download request if passed in. | ❌ | {} |
| ext | Sets the file extension. Useful for APIs that separate the image file path from its extension. Or for changing the extension. Defaults to existing file extension. | ❌ | null |
| prepareUrl | Allows modification of the URL per image if needed. Expects a function taking the original URL as a parameter and returning the desired URL. | ❌ | null |
| type | Tell the plugin that the leaf node is an _array_ of images instead of one single string. Only option here is array. For example usage, see here. | ❌ | object |
| silent | Set to true to silence image load errors in the console. | ❌ | boolean |
| skipUndefinedUrls | 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. See here. | ❌ | boolean |

#### Example Config with Optional Options

However, you may need more optional config, which is documented here.

`javascript
module.exports = {
plugins: [
{
resolve: gatsby-plugin-remote-images,
options: {
nodeType: 'MyNodes',
imagePath: 'path.to.image',
// ALL OPTIONAL BELOW HERE:
name: 'theNewImageField',
auth: { htaccess_user: USER, htaccess_pass: PASSWORD },
ext: '.jpg',
prepareUrl: url => (url.startsWith('//') ? https:${url} : url),
},
},
],
};
`

Why?

Why do you need this plugin? The fantastic gatsby-plugin-image tool only works
on _relative_ paths to locally stored images. This lets you use it on images
from an API with an _absolute_ path. For example, look at these two response
from one GraphQL query:

_Query_

`graphql
allMyNodes {
edges {
node {
id
imageUrl
}
}
}
`

_Absolute imageUrl NOT available to gatsby-plugin-image_

`javascript
allMyNodes: [
{
node: {
id: 123,
imageUrl: 'http://remoteimage.com/url.jpg',
},
},
];
`

_Relative imageUrl IS available to gatsby-plugin-image_

`javascript
allMyNodes: [
{
node: {
id: 123,
imageUrl: 'localImages/url.jpg',
},
},
];
`

If you don't control the API that you are hitting (many third party APIs return
a field with a string to an absolute path for an image), this means those image
aren't run through gatsby-plugin-image and you lose all of the benefits.

To get the images and make them available for the above example, follow the
install instructions and your config should look like this:

`javascript
module.exports = {
plugins: [
{
resolve: gatsby-plugin-remote-images,
options: {
nodeType: 'MyNodes',
imagePath: 'imageUrl',
// OPTIONAL: Name you want to give new image field on the node.
// Defaults to 'localImage'.
name: 'allItemImages',
},
},
],
};
`

Now, if we query allMyNodes we can query as we would any gatsby-plugin-image
node:

`graphql
allMyNodes {
edges {
node {
localImage {
childImageSharp {
gatsbyImageData(width: 400)
}
}
}
}
}
`

Note: Many Gatsby source plugins already do this work for you under the
hood. So if you are working with a common CMS's Gatsby plugin, odds are that
_you don't need this!_

Common Issues

$3

Due to the way gatsby-source-graphql creates nodes, it is currently impossible
for any transformer type plugin to traverse the data from that plugin.
Please read this issue for explanation.
As soon as that as fixed in gatsby-source-graphql, this plugin will be tested
to make sure it works with it as well.

$3

Since some GraphQL APIs will send back objects with nested arrays where your
target data lives, gatsby-plugin-remote-images also supports traversing
objects that have arrays at arbitrary depths. To opt in to this feature, add an
array literal, [], to the end of the node you want to indicate is an array.

Given an object structure like this:

`javascript
allMyNodes {
nodes: [
{
imageUrl: 'https://...'
},
...
]
}
`

To get the images and make them available for the above example, your config
should look like this:

`javascript
module.exports = {
plugins: [
{
resolve: gatsby-plugin-remote-images,
options: {
nodeType: 'MyNodes',
imagePath: 'nodes[].imageUrl',
},
},
],
};
`

Now, if we query allMyNodes we can query as we would any gatsby-plugin-image
node:

`graphql
allMyNodes {
nodes {
localImage {
childImageSharp {
gatsbyImageData(width: 400)
}
}
}
}
`

Note: While lodash .get doesn't natively support this syntax, it is still
used to traverse the object structure, so
the documentation for .get still
applies in full.

$3

In case your API offers an image path to an _array_ of images, instead of just
one, there is a way to handle that with the plugin. For instances where there is
an array somewhere along the _path to_ the images,
see above.

For example, you API returns:

`javascript
// MyNode
{
date: '1-1-2010',
category: 'cats'
// Note that here there are multiple images at the leaf node where the images are found.
images: [
'https://.../image1.png',
'https://.../image2.png'
]
}
`

To make your local image field an array of these images, adjust your config
accordingly:

`javascript
{
resolve: gatsby-plugin-remote-images,
options: {
nodeType: 'MyNodes',
// Making this plural (optional).
name: 'localImages',
// Path to the leaf node.
imagePath: 'images',
// Set type to array.
type: 'array'
}
}
`

Now, if we query allMyNodes we can query as we would any gatsby-plugin-image
node, but now localImage (or localImages as in the example above) we would
get an array of Gatsby images, instead of just one.

`graphql
allMyNodes {
nodes {
localImages {
childImageSharp {
gatsbyImageData(width: 400)
}
}
}
}
``