Firebase Hosting API . projects . sites . releases

Instance Methods

create(parent, body=None, versionName=None, x__xgafv=None)

Creates a new release which makes the content of the specified version

list(parent, pageToken=None, pageSize=None, x__xgafv=None)

Lists the releases that have been created on the specified site.

list_next(previous_request, previous_response)

Retrieves the next page of results.

Method Details

create(parent, body=None, versionName=None, x__xgafv=None)
Creates a new release which makes the content of the specified version
actively display on the appropriate URL(s).

Args:
  parent: string, Required. The site that the release belongs to, in the format:
<code>sites/<var>site-name</var></code> (required)
  body: object, The request body.
    The object takes the form of:

{ # A `Release` is a particular
    # [collection of configurations and files](sites.versions)
    # that is set to be public at a particular time.
  "version": { # A `Version` is the collection of configuration and # Output only. The configuration and content that was released.
      # [static files](sites.versions.files) that determine how a site is displayed.
    "deleteUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `DELETED` the version.
        # a release or finalizing a version.
      "email": "A String", # The email address of the user when the user performed the action.
      "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
          # changed their email address or deleted their account.
    },
    "finalizeUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `FINALIZED` the version.
        # a release or finalizing a version.
      "email": "A String", # The email address of the user when the user performed the action.
      "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
          # changed their email address or deleted their account.
    },
    "deleteTime": "A String", # Output only. The time at which the version was `DELETED`.
    "preview": { # Version preview configuration. If active and unexpired, # Version preview configuration for the site version. This configuration
        # specfies whether previewing is enabled for this site version. Version
        # previews allow you to preview your site at a custom URL before
        # releasing it as the live version.
        # this version will be accessible via a custom URL even
        # if it is not the currently released version.
      "active": True or False, # If true, preview URLs are enabled for this version.
      "expireTime": "A String", # Indicates the expiration time for previewing this
          # version; preview URL requests received after this time will 404.
    },
    "labels": { # The labels used for extra metadata and/or filtering.
      "a_key": "A String",
    },
    "createTime": "A String", # Output only. The time at which the version was created.
    "versionBytes": "A String", # Output only. The total stored bytesize of the version.
        # <br>This value is calculated after a version is `FINALIZED`.
    "finalizeTime": "A String", # Output only. The time at which the version was `FINALIZED`.
    "status": "A String", # The deploy status of a version.
        # <br>
        # <br>For a successful deploy, call the
        # [`CreateVersion`](sites.versions/create) endpoint to make a new version
        # (`CREATED` status),
        # [upload all desired files](sites.versions/populateFiles) to the version,
        # then [update](sites.versions/patch) the version to the `FINALIZED` status.
        # <br>
        # <br>Note that if you leave the version in the `CREATED` state for more
        # than 12&nbsp;hours, the system will automatically mark the version as
        # `ABANDONED`.
        # <br>
        # <br>You can also change the status of a version to `DELETED` by calling the
        # [`DeleteVersion`](sites.versions/delete) endpoint.
    "config": { # The configuration for how incoming requests to a site should be routed and # The configuration for the behavior of the site. This configuration exists
        # in the [`firebase.json`](/docs/cli/#the_firebasejson_file) file.
        # processed before serving content. The patterns are matched and applied
        # according to a specific
        # [priority order](/docs/hosting/full-config#hosting_priority_order).
      "redirects": [ # A list of globs that will cause the response to redirect to another
          # location.
        { # A [`redirect`](/docs/hosting/full-config#redirects) represents the
            # configuration for returning an HTTP redirect response given a matching
            # request URL path.
          "glob": "A String", # The user-supplied [glob
              # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
              # against the request URL path.
          "statusCode": 42, # Required. The status HTTP code to return in the response. It must be a
              # valid 3xx status code.
          "regex": "A String", # The user-supplied RE2 regular expression to match against the request
              # URL path.
          "location": "A String", # Required. The value to put in the HTTP location header of the response.
              # <br>The location can contain capture group values from the pattern using
              # a `:` prefix to identify the segment and an optional `*` to capture the
              # rest of the URL.
              # For example:
              # <code>"glob": "/:capture*",
              # <br>"statusCode": 301,
              # <br>"location": "https://example.com/foo/:capture"</code>
        },
      ],
      "headers": [ # A list of custom response headers that are added to the content if the
          # request URL path matches the glob.
        { # A [`header`](/docs/hosting/full-config#headers) defines custom headers to
            # add to a response should the request URL path match the pattern.
          "regex": "A String", # The user-supplied RE2 regular expression to match against the request
              # URL path.
          "glob": "A String", # The user-supplied [glob
              # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
              # against the request URL path.
          "headers": { # Required. The additional headers to add to the response.
            "a_key": "A String",
          },
        },
      ],
      "appAssociation": "A String", # How to handle well known App Association files.
      "trailingSlashBehavior": "A String", # Defines how to handle a trailing slash in the URL path.
      "cleanUrls": True or False, # Defines whether to drop the file extension from uploaded files.
      "rewrites": [ # A list of rewrites that will act as if the service were given the
          # destination URL.
        { # A [`rewrite`](/docs/hosting/full-config#rewrites) represents an internal
            # content rewrite on the version. If the pattern matches, the request will be
            # handled as if it were to the destination path specified in the
            # configuration.
          "regex": "A String", # The user-supplied RE2 regular expression to match against the request
              # URL path.
          "dynamicLinks": True or False, # The request will be forwarded to Firebase Dynamic Links.
          "run": { # A configured rewrite that directs requests to a Cloud Run service. If the # The request will be forwarded to Cloud Run.
              # Cloud Run service does not exist when setting or updating your Firebase
              # Hosting configuration, then the request fails. Any errors from the Cloud Run
              # service are passed to the end user (for example, if you delete a service, any
              # requests directed to that service receive a `404` error).
            "region": "A String", # Optional. User-provided region where the Cloud Run service is hosted.<br>
                # Defaults to `us-central1` if not supplied.
            "serviceId": "A String", # Required. User-defined ID of the Cloud Run service.
          },
          "glob": "A String", # The user-supplied [glob
              # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
              # against the request URL path.
          "path": "A String", # The URL path to rewrite the request to.
          "function": "A String", # The function to proxy requests to. Must match the exported function
              # name exactly.
        },
      ],
    },
    "name": "A String", # The unique identifier for a version, in the format:
        # <code>sites/<var>site-name</var>/versions/<var>versionID</var></code>
        # This name is provided in the response body when you call the
        # [`CreateVersion`](../sites.versions/create) endpoint.
    "createUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the version.
        # a release or finalizing a version.
      "email": "A String", # The email address of the user when the user performed the action.
      "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
          # changed their email address or deleted their account.
    },
    "fileCount": "A String", # Output only. The total number of files associated with the version.
        # <br>This value is calculated after a version is `FINALIZED`.
  },
  "message": "A String", # The deploy description when the release was created. The value can be up to
      # 512&nbsp;characters.
  "releaseUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the release.
      # a release or finalizing a version.
    "email": "A String", # The email address of the user when the user performed the action.
    "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
        # changed their email address or deleted their account.
  },
  "releaseTime": "A String", # Output only. The time at which the version is set to be public.
  "name": "A String", # Output only. The unique identifier for the release, in the format:
      # <code>sites/<var>site-name</var>/releases/<var>releaseID</var></code>
      # This name is provided in the response body when you call the
      # [`CreateRelease`](sites.releases/create) endpoint.
  "type": "A String", # Explains the reason for the release.
      # <br>Specify a value for this field only when creating a `SITE_DISABLE`
      # type release.
}

  versionName: string, The unique identifier for a version, in the format:
<code>/sites/<var>site-name</var>/versions/<var>versionID</var></code>
The <var>site-name</var> in this version identifier must match the
<var>site-name</var> in the `parent` parameter.
<br>
<br>This query parameter must be empty if the `type` field in the
request body is `SITE_DISABLE`.
  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A `Release` is a particular
      # [collection of configurations and files](sites.versions)
      # that is set to be public at a particular time.
    "version": { # A `Version` is the collection of configuration and # Output only. The configuration and content that was released.
        # [static files](sites.versions.files) that determine how a site is displayed.
      "deleteUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `DELETED` the version.
          # a release or finalizing a version.
        "email": "A String", # The email address of the user when the user performed the action.
        "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
            # changed their email address or deleted their account.
      },
      "finalizeUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `FINALIZED` the version.
          # a release or finalizing a version.
        "email": "A String", # The email address of the user when the user performed the action.
        "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
            # changed their email address or deleted their account.
      },
      "deleteTime": "A String", # Output only. The time at which the version was `DELETED`.
      "preview": { # Version preview configuration. If active and unexpired, # Version preview configuration for the site version. This configuration
          # specfies whether previewing is enabled for this site version. Version
          # previews allow you to preview your site at a custom URL before
          # releasing it as the live version.
          # this version will be accessible via a custom URL even
          # if it is not the currently released version.
        "active": True or False, # If true, preview URLs are enabled for this version.
        "expireTime": "A String", # Indicates the expiration time for previewing this
            # version; preview URL requests received after this time will 404.
      },
      "labels": { # The labels used for extra metadata and/or filtering.
        "a_key": "A String",
      },
      "createTime": "A String", # Output only. The time at which the version was created.
      "versionBytes": "A String", # Output only. The total stored bytesize of the version.
          # <br>This value is calculated after a version is `FINALIZED`.
      "finalizeTime": "A String", # Output only. The time at which the version was `FINALIZED`.
      "status": "A String", # The deploy status of a version.
          # <br>
          # <br>For a successful deploy, call the
          # [`CreateVersion`](sites.versions/create) endpoint to make a new version
          # (`CREATED` status),
          # [upload all desired files](sites.versions/populateFiles) to the version,
          # then [update](sites.versions/patch) the version to the `FINALIZED` status.
          # <br>
          # <br>Note that if you leave the version in the `CREATED` state for more
          # than 12&nbsp;hours, the system will automatically mark the version as
          # `ABANDONED`.
          # <br>
          # <br>You can also change the status of a version to `DELETED` by calling the
          # [`DeleteVersion`](sites.versions/delete) endpoint.
      "config": { # The configuration for how incoming requests to a site should be routed and # The configuration for the behavior of the site. This configuration exists
          # in the [`firebase.json`](/docs/cli/#the_firebasejson_file) file.
          # processed before serving content. The patterns are matched and applied
          # according to a specific
          # [priority order](/docs/hosting/full-config#hosting_priority_order).
        "redirects": [ # A list of globs that will cause the response to redirect to another
            # location.
          { # A [`redirect`](/docs/hosting/full-config#redirects) represents the
              # configuration for returning an HTTP redirect response given a matching
              # request URL path.
            "glob": "A String", # The user-supplied [glob
                # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                # against the request URL path.
            "statusCode": 42, # Required. The status HTTP code to return in the response. It must be a
                # valid 3xx status code.
            "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                # URL path.
            "location": "A String", # Required. The value to put in the HTTP location header of the response.
                # <br>The location can contain capture group values from the pattern using
                # a `:` prefix to identify the segment and an optional `*` to capture the
                # rest of the URL.
                # For example:
                # <code>"glob": "/:capture*",
                # <br>"statusCode": 301,
                # <br>"location": "https://example.com/foo/:capture"</code>
          },
        ],
        "headers": [ # A list of custom response headers that are added to the content if the
            # request URL path matches the glob.
          { # A [`header`](/docs/hosting/full-config#headers) defines custom headers to
              # add to a response should the request URL path match the pattern.
            "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                # URL path.
            "glob": "A String", # The user-supplied [glob
                # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                # against the request URL path.
            "headers": { # Required. The additional headers to add to the response.
              "a_key": "A String",
            },
          },
        ],
        "appAssociation": "A String", # How to handle well known App Association files.
        "trailingSlashBehavior": "A String", # Defines how to handle a trailing slash in the URL path.
        "cleanUrls": True or False, # Defines whether to drop the file extension from uploaded files.
        "rewrites": [ # A list of rewrites that will act as if the service were given the
            # destination URL.
          { # A [`rewrite`](/docs/hosting/full-config#rewrites) represents an internal
              # content rewrite on the version. If the pattern matches, the request will be
              # handled as if it were to the destination path specified in the
              # configuration.
            "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                # URL path.
            "dynamicLinks": True or False, # The request will be forwarded to Firebase Dynamic Links.
            "run": { # A configured rewrite that directs requests to a Cloud Run service. If the # The request will be forwarded to Cloud Run.
                # Cloud Run service does not exist when setting or updating your Firebase
                # Hosting configuration, then the request fails. Any errors from the Cloud Run
                # service are passed to the end user (for example, if you delete a service, any
                # requests directed to that service receive a `404` error).
              "region": "A String", # Optional. User-provided region where the Cloud Run service is hosted.<br>
                  # Defaults to `us-central1` if not supplied.
              "serviceId": "A String", # Required. User-defined ID of the Cloud Run service.
            },
            "glob": "A String", # The user-supplied [glob
                # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                # against the request URL path.
            "path": "A String", # The URL path to rewrite the request to.
            "function": "A String", # The function to proxy requests to. Must match the exported function
                # name exactly.
          },
        ],
      },
      "name": "A String", # The unique identifier for a version, in the format:
          # <code>sites/<var>site-name</var>/versions/<var>versionID</var></code>
          # This name is provided in the response body when you call the
          # [`CreateVersion`](../sites.versions/create) endpoint.
      "createUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the version.
          # a release or finalizing a version.
        "email": "A String", # The email address of the user when the user performed the action.
        "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
            # changed their email address or deleted their account.
      },
      "fileCount": "A String", # Output only. The total number of files associated with the version.
          # <br>This value is calculated after a version is `FINALIZED`.
    },
    "message": "A String", # The deploy description when the release was created. The value can be up to
        # 512&nbsp;characters.
    "releaseUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the release.
        # a release or finalizing a version.
      "email": "A String", # The email address of the user when the user performed the action.
      "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
          # changed their email address or deleted their account.
    },
    "releaseTime": "A String", # Output only. The time at which the version is set to be public.
    "name": "A String", # Output only. The unique identifier for the release, in the format:
        # <code>sites/<var>site-name</var>/releases/<var>releaseID</var></code>
        # This name is provided in the response body when you call the
        # [`CreateRelease`](sites.releases/create) endpoint.
    "type": "A String", # Explains the reason for the release.
        # <br>Specify a value for this field only when creating a `SITE_DISABLE`
        # type release.
  }
list(parent, pageToken=None, pageSize=None, x__xgafv=None)
Lists the releases that have been created on the specified site.

Args:
  parent: string, Required. The parent for which to list files, in the format:
<code>sites/<var>site-name</var></code> (required)
  pageToken: string, The next_page_token from a previous request, if provided.
  pageSize: integer, The page size to return. Defaults to 100.
  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    {
    "releases": [ # The list of hashes of files that still need to be uploaded, if any exist.
      { # A `Release` is a particular
          # [collection of configurations and files](sites.versions)
          # that is set to be public at a particular time.
        "version": { # A `Version` is the collection of configuration and # Output only. The configuration and content that was released.
            # [static files](sites.versions.files) that determine how a site is displayed.
          "deleteUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `DELETED` the version.
              # a release or finalizing a version.
            "email": "A String", # The email address of the user when the user performed the action.
            "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
                # changed their email address or deleted their account.
          },
          "finalizeUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who `FINALIZED` the version.
              # a release or finalizing a version.
            "email": "A String", # The email address of the user when the user performed the action.
            "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
                # changed their email address or deleted their account.
          },
          "deleteTime": "A String", # Output only. The time at which the version was `DELETED`.
          "preview": { # Version preview configuration. If active and unexpired, # Version preview configuration for the site version. This configuration
              # specfies whether previewing is enabled for this site version. Version
              # previews allow you to preview your site at a custom URL before
              # releasing it as the live version.
              # this version will be accessible via a custom URL even
              # if it is not the currently released version.
            "active": True or False, # If true, preview URLs are enabled for this version.
            "expireTime": "A String", # Indicates the expiration time for previewing this
                # version; preview URL requests received after this time will 404.
          },
          "labels": { # The labels used for extra metadata and/or filtering.
            "a_key": "A String",
          },
          "createTime": "A String", # Output only. The time at which the version was created.
          "versionBytes": "A String", # Output only. The total stored bytesize of the version.
              # <br>This value is calculated after a version is `FINALIZED`.
          "finalizeTime": "A String", # Output only. The time at which the version was `FINALIZED`.
          "status": "A String", # The deploy status of a version.
              # <br>
              # <br>For a successful deploy, call the
              # [`CreateVersion`](sites.versions/create) endpoint to make a new version
              # (`CREATED` status),
              # [upload all desired files](sites.versions/populateFiles) to the version,
              # then [update](sites.versions/patch) the version to the `FINALIZED` status.
              # <br>
              # <br>Note that if you leave the version in the `CREATED` state for more
              # than 12&nbsp;hours, the system will automatically mark the version as
              # `ABANDONED`.
              # <br>
              # <br>You can also change the status of a version to `DELETED` by calling the
              # [`DeleteVersion`](sites.versions/delete) endpoint.
          "config": { # The configuration for how incoming requests to a site should be routed and # The configuration for the behavior of the site. This configuration exists
              # in the [`firebase.json`](/docs/cli/#the_firebasejson_file) file.
              # processed before serving content. The patterns are matched and applied
              # according to a specific
              # [priority order](/docs/hosting/full-config#hosting_priority_order).
            "redirects": [ # A list of globs that will cause the response to redirect to another
                # location.
              { # A [`redirect`](/docs/hosting/full-config#redirects) represents the
                  # configuration for returning an HTTP redirect response given a matching
                  # request URL path.
                "glob": "A String", # The user-supplied [glob
                    # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                    # against the request URL path.
                "statusCode": 42, # Required. The status HTTP code to return in the response. It must be a
                    # valid 3xx status code.
                "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                    # URL path.
                "location": "A String", # Required. The value to put in the HTTP location header of the response.
                    # <br>The location can contain capture group values from the pattern using
                    # a `:` prefix to identify the segment and an optional `*` to capture the
                    # rest of the URL.
                    # For example:
                    # <code>"glob": "/:capture*",
                    # <br>"statusCode": 301,
                    # <br>"location": "https://example.com/foo/:capture"</code>
              },
            ],
            "headers": [ # A list of custom response headers that are added to the content if the
                # request URL path matches the glob.
              { # A [`header`](/docs/hosting/full-config#headers) defines custom headers to
                  # add to a response should the request URL path match the pattern.
                "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                    # URL path.
                "glob": "A String", # The user-supplied [glob
                    # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                    # against the request URL path.
                "headers": { # Required. The additional headers to add to the response.
                  "a_key": "A String",
                },
              },
            ],
            "appAssociation": "A String", # How to handle well known App Association files.
            "trailingSlashBehavior": "A String", # Defines how to handle a trailing slash in the URL path.
            "cleanUrls": True or False, # Defines whether to drop the file extension from uploaded files.
            "rewrites": [ # A list of rewrites that will act as if the service were given the
                # destination URL.
              { # A [`rewrite`](/docs/hosting/full-config#rewrites) represents an internal
                  # content rewrite on the version. If the pattern matches, the request will be
                  # handled as if it were to the destination path specified in the
                  # configuration.
                "regex": "A String", # The user-supplied RE2 regular expression to match against the request
                    # URL path.
                "dynamicLinks": True or False, # The request will be forwarded to Firebase Dynamic Links.
                "run": { # A configured rewrite that directs requests to a Cloud Run service. If the # The request will be forwarded to Cloud Run.
                    # Cloud Run service does not exist when setting or updating your Firebase
                    # Hosting configuration, then the request fails. Any errors from the Cloud Run
                    # service are passed to the end user (for example, if you delete a service, any
                    # requests directed to that service receive a `404` error).
                  "region": "A String", # Optional. User-provided region where the Cloud Run service is hosted.<br>
                      # Defaults to `us-central1` if not supplied.
                  "serviceId": "A String", # Required. User-defined ID of the Cloud Run service.
                },
                "glob": "A String", # The user-supplied [glob
                    # pattern](/docs/hosting/full-config#glob_pattern_matching) to match
                    # against the request URL path.
                "path": "A String", # The URL path to rewrite the request to.
                "function": "A String", # The function to proxy requests to. Must match the exported function
                    # name exactly.
              },
            ],
          },
          "name": "A String", # The unique identifier for a version, in the format:
              # <code>sites/<var>site-name</var>/versions/<var>versionID</var></code>
              # This name is provided in the response body when you call the
              # [`CreateVersion`](../sites.versions/create) endpoint.
          "createUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the version.
              # a release or finalizing a version.
            "email": "A String", # The email address of the user when the user performed the action.
            "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
                # changed their email address or deleted their account.
          },
          "fileCount": "A String", # Output only. The total number of files associated with the version.
              # <br>This value is calculated after a version is `FINALIZED`.
        },
        "message": "A String", # The deploy description when the release was created. The value can be up to
            # 512&nbsp;characters.
        "releaseUser": { # Contains metadata about the user who performed an action, such as creating # Output only. Identifies the user who created the release.
            # a release or finalizing a version.
          "email": "A String", # The email address of the user when the user performed the action.
          "imageUrl": "A String", # A profile image URL for the user. May not be present if the user has
              # changed their email address or deleted their account.
        },
        "releaseTime": "A String", # Output only. The time at which the version is set to be public.
        "name": "A String", # Output only. The unique identifier for the release, in the format:
            # <code>sites/<var>site-name</var>/releases/<var>releaseID</var></code>
            # This name is provided in the response body when you call the
            # [`CreateRelease`](sites.releases/create) endpoint.
        "type": "A String", # Explains the reason for the release.
            # <br>Specify a value for this field only when creating a `SITE_DISABLE`
            # type release.
      },
    ],
    "nextPageToken": "A String", # If there are additional releases remaining beyond the ones in this
        # response, then supply this token in the next
        # [`list`](../sites.versions.files/list) call to continue with the next set
        # of releases.
  }
list_next(previous_request, previous_response)
Retrieves the next page of results.

Args:
  previous_request: The request for the previous page. (required)
  previous_response: The response from the request for the previous page. (required)

Returns:
  A request object that you can call 'execute()' on to request the next
  page. Returns None if there are no more items in the collection.