Lección 29: Importando una entrada desde otro sitio WordPress
Esta lección del tutorial demuestra cómo podemos mantener sitios WordPress sincronizados, importando una entrada desde algún sitio WordPress a nuestro sitio WordPress local.
Consulta GraphQL para importar una entrada desde otro sitio WordPress
La consulta GraphQL de abajo se conecta al endpoint GraphQL de un sitio web upstream, obtiene los datos para una entrada específica, y la importa localmente. El plugin Gato GraphQL (versión gratuita) debe estar instalado también en el sitio web upstream.
(Si Gato GraphQL no está instalado en el sitio upstream, la consulta puede adaptarse para conectarse a sus endpoints de la API REST de WP en su lugar.)
Los recursos referenciados en la entrada deben todos existir localmente:
- El autor
- La imagen destacada (si la hay)
- Las categorías
- (Las etiquetas también, sin embargo si éstas aún no existen, se crean junto con la entrada, así que no es un problema)
Como identificador común para recursos entre los sitios upstream y local, usamos:
- Slugs para categorías, etiquetas y elementos multimedia
- Usernames para usuarios
Si alguno de los recursos no existe en el sitio local, la consulta GraphQL imprime un error y detiene la importación.
query InitializeDynamicVariables
@configureWarningsOnExportingDuplicateVariable(enabled: false)
{
initVariablesWithFalse: _echo(value: false)
@export(as: "requestProducedErrors")
@export(as: "responseHasErrors")
@export(as: "postIsMissing")
@export(as: "postHasAuthor")
@export(as: "postHasFeaturedImage")
@export(as: "postHasCategories")
@export(as: "postHasTags")
@remove
initVariablesWithNull: _echo(value: null)
@export(as: "existingAuthorUsername")
@export(as: "existingFeaturedImageSlug")
@export(as: "featuredImageMutationInput")
@remove
initVariablesWithEmptyArray: _echo(value: [])
@export(as: "existingCategorySlugs")
@export(as: "existingTagSlugs")
@remove
}
query CheckIfPostExistsLocally($postSlug: String!)
@depends(on: "InitializeDynamicVariables")
{
localPost: post(
by: { slug: $postSlug }
status: any
) {
id
}
postAlreadyExists: _notNull(value: $__localPost)
@export(as: "postAlreadyExists")
}
query FailIfPostAlreadyExistsLocally($postSlug: String!)
@depends(on: "CheckIfPostExistsLocally")
@include(if: $postAlreadyExists)
{
errorMessage: _sprintf(
string: "Post with slug '%s' already exists locally",
values: [$postSlug]
) @remove
_fail(
message: $__errorMessage
data: {
slug: $postSlug
}
) @remove
createPost: _echo(value: null)
}
query ConnectToGraphQLAPI(
$upstreamServerGraphQLEndpointURL: String!
$postSlug: String!
)
@depends(on: "FailIfPostAlreadyExistsLocally")
@skip(if: $postAlreadyExists)
{
externalData: _sendGraphQLHTTPRequest(input:{
endpoint: $upstreamServerGraphQLEndpointURL,
query: """
query GetPost($postSlug: String!) {
post(by: { slug: $postSlug }) {
id
slug
rawTitle
rawContent
rawExcerpt
author {
id
username
}
featuredImage {
id
slug
}
categories {
id
slug
}
tags {
id
slug
}
}
}
""",
variables: [
{
name: "postSlug",
value: $postSlug
}
]
})
@export(as: "externalData")
requestProducedErrors: _isNull(value: $__externalData)
@export(as: "requestProducedErrors")
@remove
}
query ValidateResponse
@depends(on: "ConnectToGraphQLAPI")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
{
responseHasErrors: _propertyIsSetInJSONObject(
object: $externalData
by: {
key: "errors"
}
)
@export(as: "responseHasErrors")
@remove
postExists: _propertyIsSetInJSONObject(
object: $externalData
by: {
path: "data.post"
}
)
@remove
postIsMissing: _not(value: $__postExists)
@export(as: "postIsMissing")
@remove
}
query FailIfResponseHasErrors
@depends(on: "ValidateResponse")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $postIsMissing)
@include(if: $responseHasErrors)
{
errors: _objectProperty(
object: $externalData,
by: {
key: "errors"
}
) @remove
_fail(
message: "Executing the GraphQL query against the upstream webserver produced error(s)"
data: {
errors: $__errors
}
) @remove
createPost: _echo(value: null)
}
query FailIfPostNotExists($postSlug: String!)
@depends(on: "FailIfResponseHasErrors")
@skip(if: $requestProducedErrors)
@include(if: $postIsMissing)
{
errorMessage: _sprintf(
string: "There is no post with slug '%s' in the origin",
values: [$postSlug]
) @remove
_fail(
message: $__errorMessage
data: {
slug: $postSlug
}
) @remove
createPost: _echo(value: null)
}
query ExportInputs
@depends(on: "FailIfPostNotExists")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $responseHasErrors)
@skip(if: $postIsMissing)
{
postData: _objectProperty(
object: $externalData,
by: { path: "data.post" }
) @remove
postTitle: _objectProperty(
object: $__postData,
by: { key: "rawTitle" }
)
@export(as: "postTitle")
@remove
postContent: _objectProperty(
object: $__postData,
by: { key: "rawContent" }
)
@export(as: "postContent")
@remove
postExcerpt: _objectProperty(
object: $__postData,
by: { key: "rawExcerpt" }
)
@export(as: "postExcerpt")
@remove
postAuthorUsername: _objectProperty(
object: $__postData,
by: { key: "author" }
)
@passOnwards(
as: "author"
)
@applyField(
name: "_notNull",
arguments: {
value: $author
},
passOnwardsAs: "hasAuthor"
)
@if(condition: $hasAuthor)
@applyField(
name: "_objectProperty",
arguments: {
object: $author,
by: { key: "username" }
},
setResultInResponse: true
)
@export(as: "postAuthorUsername")
@remove
postHasAuthor: _notNull(
value: $__postAuthorUsername
)
@export(as: "postHasAuthor")
@remove
postFeaturedImageSlug: _objectProperty(
object: $__postData,
by: { key: "featuredImage" }
)
@passOnwards(
as: "featuredImage"
)
@applyField(
name: "_notNull",
arguments: {
value: $featuredImage
},
passOnwardsAs: "hasFeaturedImage"
)
@if(condition: $hasFeaturedImage)
@applyField(
name: "_objectProperty",
arguments: {
object: $featuredImage,
by: { key: "slug" }
},
setResultInResponse: true
)
@export(as: "postFeaturedImageSlug")
@remove
postHasFeaturedImage: _notNull(
value: $__postFeaturedImageSlug
)
@export(as: "postHasFeaturedImage")
@remove
postCategorySlugs: _objectProperty(
object: $__postData,
by: { key: "categories" }
)
@underEachArrayItem(
passValueOnwardsAs: "category"
)
@applyField(
name: "_objectProperty"
arguments: {
object: $category,
by: {
key: "slug"
}
}
setResultInResponse: true
)
@export(as: "postCategorySlugs")
@remove
postHasCategories: _notEmpty(
value: $__postCategorySlugs
)
@export(as: "postHasCategories")
@remove
postTagSlugs: _objectProperty(
object: $__postData,
by: { key: "tags" }
)
@underEachArrayItem(
passValueOnwardsAs: "tag"
)
@applyField(
name: "_objectProperty"
arguments: {
object: $tag,
by: {
key: "slug"
}
}
setResultInResponse: true
)
@export(as: "postTagSlugs")
@remove
postHasTags: _notEmpty(
value: $__postTagSlugs
)
@export(as: "postHasTags")
@remove
}
query ExportExistingResources
@depends(on: "ExportInputs")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $responseHasErrors)
@skip(if: $postIsMissing)
{
existingAuthorByUsername: user(by: { username: $postAuthorUsername })
@include(if: $postHasAuthor)
{
id
username @export(as: "existingAuthorUsername")
}
existingFeaturedImageBySlug: mediaItem(by: { slug: $postFeaturedImageSlug })
@include(if: $postHasFeaturedImage)
{
id
slug @export(as: "existingFeaturedImageSlug")
}
existingCategoriesBySlug: postCategories(filter: { slugs: $postCategorySlugs })
@include(if: $postHasCategories)
{
id
slug @export(as: "existingCategorySlugs", type: LIST)
}
existingTagsBySlug: postTags(filter: { slugs: $postTagSlugs })
@include(if: $postHasTags)
{
id
slug @export(as: "existingTagSlugs", type: LIST)
}
}
query ExportMissingResources
@depends(on: "ExportExistingResources")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $responseHasErrors)
@skip(if: $postIsMissing)
{
isAuthorMissing: _notEquals(
value1: $postAuthorUsername,
value2: $existingAuthorUsername
) @export(as: "isAuthorMissing")
isFeaturedImageMissing: _notEquals(
value1: $postFeaturedImageSlug,
value2: $existingFeaturedImageSlug
) @export(as: "isFeaturedImageMissing")
missingCategorySlugs: _arrayDiff(
arrays: [$postCategorySlugs, $existingCategorySlugs]
) @export(as: "missingCategorySlugs")
areCategoriesMissing: _notEmpty(
value: $__missingCategorySlugs
) @export(as: "areCategoriesMissing")
# missingTagSlugs: _arrayDiff(
# arrays: [$postTagSlugs, $existingTagSlugs]
# ) @export(as: "missingTagSlugs")
# areTagsMissing: _notEmpty(
# value: $__missingTagSlugs
# ) @export(as: "areTagsMissing")
isAnyResourceMissing: _or(
values: [
$__isAuthorMissing,
$__isFeaturedImageMissing,
$__areCategoriesMissing,
# $__areTagsMissing,
]
) @export(as: "isAnyResourceMissing")
}
query FailIfAnyResourceIsMissing
@depends(on: "ExportMissingResources")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $postIsMissing)
@skip(if: $responseHasErrors)
@include(if: $isAnyResourceMissing)
{
performingValidations: id
@if(condition: $isAuthorMissing)
@fail(
message: "Author is missing in local site"
data: {
missingAuthorByUsername: $postAuthorUsername
}
condition: ALWAYS
)
@if(condition: $isFeaturedImageMissing)
@fail(
message: "Featured image is missing in local site"
data: {
missingFeaturedImageBySlug: $postFeaturedImageSlug
}
condition: ALWAYS
)
@if(condition: $areCategoriesMissing)
@fail(
message: "Categories are missing in local site"
data: {
missingCategoriesBySlug: $missingCategorySlugs
}
condition: ALWAYS
)
# @if(condition: $areTagsMissing)
# @fail(
# message: "Tags are missing in local site"
# data: {
# missingTagBySlug: $missingTagSlugs
# }
# condition: ALWAYS
# )
createPost: _echo(value: null)
}
query ExportMutationInputs
@depends(on: "FailIfAnyResourceIsMissing")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $responseHasErrors)
@skip(if: $postIsMissing)
@skip(if: $isAnyResourceMissing)
{
featuredImageMutationInput: _echo(value: {
slug: $postFeaturedImageSlug
})
@include(if: $postHasFeaturedImage)
@export(as: "featuredImageMutationInput")
@remove
}
mutation ImportPost(
$postSlug: String!
)
@depends(on: "ExportMutationInputs")
@skip(if: $postAlreadyExists)
@skip(if: $requestProducedErrors)
@skip(if: $responseHasErrors)
@skip(if: $postIsMissing)
@skip(if: $isAnyResourceMissing)
{
createPost(input: {
status: draft,
slug: $postSlug
title: $postTitle
contentAs: {
html: $postContent
},
excerpt: $postExcerpt
authorBy: {
username: $postAuthorUsername
},
featuredImageBy: $featuredImageMutationInput,
categoriesBy: {
slugs: $postCategorySlugs
},
tagsBy: {
slugs: $postTagSlugs
}
}) {
status
errors {
__typename
...on ErrorPayload {
message
}
}
post {
id
date
status
slug
title
content
excerpt
author {
id
username
}
featuredImage {
id
slug
}
categories {
id
slug
}
tags {
id
slug
}
}
}
}(Como hemos visto en lecciones anteriores del tutorial) Usamos la funcionalidad Field to Input (con la sintaxis $__field) para pasar el valor resuelto del campo a un campo contiguo.
Cuando necesitamos pasar el valor resuelto del campo a una directiva, debemos en cambio usar la directiva @passOnwards (que también es proporcionada por la extensión Field To Input).
Esta consulta:
{
posts {
id
hasComments
notHasComments: _not(value: $__hasComments)
}
}...es equivalente a esta consulta:
{
posts {
id
hasComments
notHasComments: hasComments
@passOnwards(as: "postHasComments")
@applyField(
name: "_not"
arguments: {
value: $postHasComments
},
setResultInResponse: true
)
}
}@passOnwards es útil para producir algún cálculo sobre el valor del campo. Por ejemplo, en la consulta GraphQL de arriba, se usa para comprobar si la propiedad user no es null, antes de extraer su propiedad username (y sobrescribir el valor del campo con ella):
postAuthorUsername: _objectProperty(
object: $__postData,
by: { key: "author" }
)
@passOnwards(
as: "author"
)
@applyField(
name: "_notNull",
arguments: {
value: $author
},
passOnwardsAs: "hasAuthor"
)
@if(condition: $hasAuthor)
@applyField(
name: "_objectProperty",
arguments: {
object: $author,
by: { key: "username" }
},
setResultInResponse: true
)
@export(as: "postAuthorUsername")
@remove[WIP] Importando automáticamente recursos faltantes
El esquema de Gato GraphQL debe ser ampliado con mutaciones para:
Esto es un trabajo en progreso. Una vez que estas mutaciones sean soportadas, podremos hacer que la consulta GraphQL importe automáticamente cada uno de los recursos faltantes.