String interpolation in graphQL query

Question

I am new to Gatsby and its graphQL query system to retrieve assets. I have a working component Image that fetches an image and displays it. I want to have the name of the image customizable but I can't figure out how to dit.

Here is the working component:

const Image = () => (
  <StaticQuery
    query={graphql`
      query {
        // fetching the image gatsby-astronaut.png
        placeholderImage: file(relativePath: { eq: "gatsby-astronaut.png" }) {
          childImageSharp {
            fluid(maxWidth: 300) {
              ...GatsbyImageSharpFluid
            }
          }
        }
      }
    `}
    render={data => <Img fluid={data.placeholderImage.childImageSharp.fluid} />}
  />
);

And here is what I tried to have a customizable image:

const Image = ({ imgName }: { imgName: string }) => (
  <StaticQuery
    query={graphql`
      query {
        // fetching the image imgName
        placeholderImage: file(relativePath: { eq: "${imgName}.png" }) {
          childImageSharp {
            fluid(maxWidth: 300) {
              ...GatsbyImageSharpFluid
            }
          }
        }
      }
    `}
    render={data => <Img fluid={data.placeholderImage.childImageSharp.fluid} />}
  />
);

But it raises the following error for the query:

Expected 1 arguments, but got 2.ts(2554)

How can I have a customizable image name?

Answer 1

Here is the easy way I ran into:

const Image = props => {
  const data = useStaticQuery(graphql`
    query {
      firstImg: file(relativePath: { eq: "firstImg.png" }) {
        childImageSharp {
          fluid(maxWidth: 300) {
            ...GatsbyImageSharpFluid
          }
        }
      }

      secondImg: file(
        relativePath: { eq: "secondImg.png" }
      ) {
        childImageSharp {
          fluid(maxWidth: 300) {
            ...GatsbyImageSharpFluid
          }
        }
      }
    }
  `)

  switch (props.name) {
    case "firstImg":
      return <Img fluid={data.firstImg.childImageSharp.fluid} />
    case "secondImg":
      return <Img fluid={data.secondImg.childImageSharp.fluid} />
    default:
      return <Img />
  }
}

and use it like this:

<Image name="firstImg" />

You can also make it typo-safe by introducing an object with all the images you might want to display, like this:

const Images = { firstImg: 'firstImg', secondImg: 'secondImg' }

and then use it like this:

<Image name={Images.firstImage} />

and

...
switch (props.name) {
case Images.firstImage:
...