emlynoregan

def MyLongRunningFunction(resolve):
  try:
    # we're in a separate task. Do something long running!
    # eventually call resolve(result), with whatever result you made 
  except Exception, ex:
    resolve(ex)

def MyFunctionToRunAfterThat(result):
  try:
    value = result.value 

emlynoregan

def DoABigThing(aListOfNumbers, callWhenSucceededF, callWhenFailedF):
  def DoTheThing(resolve, initialValue):
    theSum = sum(aListOfNumbers) + initialValue
    theSum += # also get some stuff from a webservice or datastore or something else slow?
    resolve(theSum)

  def DoneTheThing(result):
    try:
      callWhenSucceededF(result.value)
    except Exception, ex:

emlynoregan

# This is a generic map function for the datastore.
# Suitable for passing to the PromiseSpace.when() method.
# outerresolve: this function is called when the mapping is complete, with the full result.
# promiseSpace: a promise space, to be used for making promises.
# dsQuery: an ndb datastore query.
# mapF: an optional map function. Takes an object or key (depending on keyOnly) and returns something.
# reduceF: an optional reduce function. Takes a list of results of mapping and a previous return value 
#   from reduceF, and returns a new value
# keyOnly: determines whether the queries fetch objects or just keys
# pageSize: size of the pages fetched from the query

emlynoregan

class Greeting(ndb.Model):
    """Models an individual Guestbook entry with content and date."""
    content = ndb.StringProperty()
    date = ndb.DateTimeProperty(auto_now_add=True)

emlynoregan

class Greeting(ndb.Model):
  ...

  def _post_put_hook(self, future):
    # replace the document for this object in the relevant search index

  @classmethod
  def _post_delete_hook(cls, key, future):
    # delete the document for this object from the relevant search index

emlynoregan

class Greeting(ndb.Model):
  ...
 
  def _post_put_hook(self, future):
    # replace the document for this object in the relevant search index
 
  @classmethod
  def _post_delete_hook(cls, key, future):
    # delete the document for this object from the relevant search index

emlynoregan

var fooschema = <some schema>
var footransform = <some transform>

var foo = function(inputmas) {
  JsonSchema.validate(inputmas, fooschema)
  return JsonTransform.transform(inputmas, footransform)
}

emlynoregan

{
  "cursor": "8b08006b-963a-6909-c132-cc618cd4b352",
  "more": true,
  "items": [
    {
      "name": "Ambassador Kosh",
      "type": "Vorlonn",
      "resources": {
        "website": "http://babylon5.wikia.com/wiki/Kosh",
        "quote": "Yes"

emlynoregan

{
  "characters": [
    {
      "_type": "section",
      "path": "$.items[*]",
      "transform": {
        "fullname": "#@.name",
        "saying": {
          "_type": "section",
          "path": "@.quote",

emlynoregan

{
  "characters": [
    {
      "fullname": "Ambassador Kosh",
      "saying": "Yes"
    },
    {
      "fullname": "Worf"
    },
    {