Server Hooks

Server Hooks allow you to

  • Influence the publication process
  • Influence the document rendering
  • Get notified about list updates

Use Cases of a Server Hook

  • Modify a document
  • Abort the publish process and return an error to the server
  • Notify other systems

Alternatives to Server Hooks

2 Types of Server Hooks

  • Project specific hooks: register as many as you need, executed in the order they got registered
  • Server wide hooks: run on every project, but are only allowed for publication hooks

Publication Hooks

With publication hooks you can influence the Document Publication Lifecycle. E.g. manipulate the content before a publish happens.

Process and Hooks Overview

NameSupported inEditor FeedbackAdded inRemoved in
preparePublishHookAsyncInstant Publishrelease-2022-03
prepublishHookAsyncInstant Publishrelease-2022-03
publishHookAsyncInstant Publishrelease-2022-03
postPublishHookAsyncInstant Publishrelease-2022-03
unpublishHookAsyncInstant Publishrelease-2017-01release-2022-05
postUnpublishHookAsyncInstant Publishrelease-2022-05

Register a Publication Hook

Two ways of registering a Publication Hook

  • registerPublicationHooks: Register as many hooks as you need, executed in the order they got registered
  • registerPublicationServerHooks: Hooks are executed on all projects. These hooks run before project specific ones.

API of Publication Hooks

  • preparePublishHookAsync: ({documentVersion}) {return}
  • postPublishHookAsync: ({documentVersion}) {return}
  • postUnpublishHookAsync: ({documentVersion}) {return}
  • Removed in: release-2022-05: unpublishHookAsync: ({documentType, documentVersion}) {return}

Example

const appConfig = require('./conf')
const liServer = require('@livingdocs/server')(appConfig)

liServer.registerInitializedHook(async () => {
  liServer.features.api('li-documents').registerPublicationServerHooks({
    async preparePublishHookAsync ({documentVersion}) { return }
  })

  liServer.features.api('li-documents').registerPublicationHooks({
    projectHandle: 'your-awesome-project',
    channelHandle: 'default',
    // Added in: release-2022-03
    async preparePublishHookAsync ({documentVersion}) { return },
    // Added in: release-2022-03
    async postPublishHookAsync ({documentVersion}) {
      liServer.log.info(`postPublishHookAsync called for documentType: ${documentVersion.documentType}!`)
      liServer.log.debug({documentVersion: documentVersion})
      return
    },
    // Removed in: release-2022-05
    async unpublishHookAsync ({documentVersion}) {
      liServer.log.info(`unpublishHookAsync called for documentType: ${documentVersion.documentType}!`)
      liServer.log.debug({documentVersion})
      return
    }
    // Added in: release-2022-05
    async postUnpublishHookAsync ({documentVersion}) {
      liServer.log.info(`unpublishHookAsync called for documentType: ${documentVersion.documentType}!`)
      liServer.log.debug({documentVersion})
      return
    }
  })
})

preparePublishHookAsync()

The preparePublishHookAsync hook allows modifications of the DocumentVersion before a document will be published.

Use Cases

  • Modify document (DocumentVersion)
  • Error feedback with throwing an error (document will not be published)

Example

async preparePublishHookAsync ({documentVersion}) {
  if (documentVersion.metadata.title === 'Let me pass') {
    // modify the document here
    return
  } else {
    // Example Validation Error for a metadata property
    const err = new Error('Metadata Errors')
    err.name = 'MetadataValidationErrors'
    err.status = 400
    err.invalidMetadata = [{
      metadataProperty: 'title'
      message: 'Invalid Title',
    }]
    throw err
  }
}

postPublishHookAsync

The postPublishHookAsync hook will be called after a document has been published. Any change to the DocumentVersion has no effect. A use case for this hook is to inform remote systems about the publication of a document.

Use Cases

  • Notify other systems

Example

async postPublishHookAsync ({documentVersion}) {
 axios.post(`https://my-remote-service.com/publish`,
  {
    projectId: documentVersion.projectId,
    documentId: documentVersion.id,
    publicationId: documentVersion.getLastPublicationId(),
  })
}

unpublishHookAsync

Removed in: release-2022-05

The unpublishHookAsync hook will be called after a document has been unpublished. Any change to the DocumentVersion has no effect. A use case for this hook is to inform remote systems about the unpublication of a document.

async unpublishHookAsync ({documentVersion}) {...}

postUnpublishHookAsync

The postUnpublishHookAsync hook will be called after a document has been unpublished or a published document gets deleted. Any change to the DocumentVersion has no effect. A use case for this hook is to inform remote systems about the unpublish of a document.

Use Cases

  • Notify other systems

Example

async postUnpublishHookAsync ({documentVersion}) {
 axios.post(`https://my-remote-service.com/unpublish`,
  {
    projectId: documentVersion.projectId,
    documentId: documentVersion.id
  })
}

Render Hooks

The beforeRenderHookAsync is called right before a document gets rendered.

API:

  • beforeRenderHookAsync: ({documentType, rendition, renditionNames})

Example:

const appConfig = require('./conf')
const liServer = require('@livingdocs/server')(appConfig)

liServer.registerInitializedHook(async () => {
  liServer.features.api('li-render-pipeline').registerRenderHooks({
    projectHandle: 'your-interesting-project',
    channelHandle: 'some-channel',
    async beforeRenderHookAsync ({contentType, rendition, renditionNames}) {
      if (['interview', 'biography'].includes(contentType)) {
        liServer.log.info("We're about to render something about somebody!")
        // do something with the rendition:
        const livingdoc = rendition.getLivingdoc()
        const galleryTeasers = livingdoc.componentTree.find('gallery-teaser')

        return extendGalleryTeasers(galleryTeasers, rendition)
      }
    }
  })
})

List Hooks

registerListHooks()

There is one hook for the document-lists feature. The hook can be registered through registerListHooks().

Example:

const appConfig = require('./conf')
const liServer = require('@livingdocs/server')(appConfig)

liServer.registerInitializedHook(async () => {
  liServer.features.api('li-document-lists').registerListHooks({
    projectHandle: 'your-interesting-project',
    channelHandle: 'some-channel',
    listUpdateHookAsync ({projectId, listId, remove, add}) {
      console.info(
        `The list with id '${listId}' in the project '${projectId}' has changes.`,
        `removing ${remove.length} things, adding ${add.length} things.`
      )
      return
    }
  })
})

listUpdateHookAsync()

The payload described here has a custom format where it gives the added and removed documentIds. An example how to use that hook would be to have Elasticsearch reindex the documents which got added/removed from a list.

listUpdateHookAsync: ({
  trx,
  eventSource, // which api method triggers the hook 'updateList' or `removeDocumentFromList`
  projectId,
  channelId,
  listId,
  remove: [30, 199],
  add: [{id: 77, order: 12}]
})