import React from 'react' ; import { Helmet } from 'react-helmet' ; import { StaticQuery , graphql } from 'gatsby' ; const detailsQuery = graphql `
  query DefaultSEOQuery {
    site {
      siteMetadata {
        title
        description
        author
      }
    }
  }
` ; const SEO = ( { description , lang , meta , keywords , title } ) => { return ( < StaticQuery query = { detailsQuery } render = { ( data ) => { const metaDescription = description || data . site . siteMetadata . description ; return ( < Helmet htmlAttributes = { { lang : lang ?? 'en' , } } title = { title } titleTemplate = { `%s | ${ data . site . siteMetadata . title }` } meta = { [ { name : 'description' , content : metaDescription , } , { property : 'og:title' , content : title , } , { property : 'og:description' , content : metaDescription , } , { property : 'og:type' , content : 'website' , } , { name : 'twitter:card' , content : 'summary' , } , { name : 'twitter:creator' , content : data . site . siteMetadata . author , } , { name : 'twitter:title' , content : title , } , { name : 'twitter:description' , content : metaDescription , } , ] . concat ( keywords && keywords . length > 0 ? { name : 'keywords' , content : keywords . join ( ', ' ) , } : [ ] ) . concat ( meta ?? [ ] ) } / > ) ; } } />); } ; SEO . defaultProps = { keywords : [ 'OAH' , 'application' , 'react' ] , } ; interface SEOProps { description ? : string ; lang ? : string ; meta ? : any [ ] ; keywords ? : string [ ] ; title : string ; } export default SEO ;