gcloud-datastore {

This package is installable by using npm install --save gcloud-datastore.

Using the Query Manager

The idea behind the query manager is a first-in-first-out stack. The query manager is essentialy a stack that holds query until they are executed. Once executed, all of the results are return in an array.

Quick Example

Here is how the query manager works, at a very basic level.

Sample datastore:

Kind: Animal

id/name	species	name
871398717813	lion	Simba
234885878798	tiger	Tony
873485798374	bear	Baloo

Code

var datastore = require('gcloud-datastore');

// Synchronous callback
datatore.addQuery(query, function(error, queryStackLength) {
    if(error)
        throw error;
    else
        console.log('There is now ' + queryStackLength + ' query in the stack.');
});

// Asynchronous callback
datastore.runAllQueries(function(error, result) {
    if(error)
        throw error;
    else
        console.log(result);
});

Documentation

datastore

• addQueries - Add an array of queries to the stack
• addQuery - Add one query to the stack
• createQuery - Creates and returns a query object
• getAllQueries - Get an array of all of the queries in the stack
• getNextQuery - Get the next query in the stack, based on the FIFO model
• getStackLength - Get the current length of the stack
• removeAllQueries - Remove all of the queries from the stack
• removeNextQuery - Remove the next query in the stack, based on the FIFO model
• runAllQueries - Run all of the queries in the stack
• runNextQuery - Run the next in the stack
• runQuery - Run a specific query

datastore

addAllQueries(queries)

A function used to add an array of queries to the stack.

Parameters

• queries - An array of query objects to be added to the stack.

Returns The new length of the stack after the queries have been inserted.

Example

var animalQuery = datastore.createQuery('Animal');
var movieQuery = datastore.createQuery('Movie');
var queries = [animalQuery, movieQuery];

var stackLength = datastore.addAllQueries(queries);

addQuery(query)

A function used to add one query to the stack.

Parameters

• query - A query object to be added to the stack.

Returns The new length of the stack after the query has been inserted.

Example

var animalQuery = datastore.createQuery('Animal');

var stackLength = datastore.addQuery(animalQuery);

createQuery([namespace], kind)

A function used to create a new Query object.

Note This acts exactly like the createQuery method supplied by the gcloud-node API.

Parameters

• namespace - An optional namespace to use for the query.
• kind - The kind to use for the query.

Returns A new Query object.

Example

var animalQuery = datastore.createQuery('Animal');

getAllQueries()

A function used to get an array containing all of the queries currently in the stack.

Returns An array containing all of the queries currently stored in the stack.

Example

var queries = datastore.getAllQueries();

getNextQuery();

A function used to get the next query to be run in the stack, based on the FIFO model.

Returns The next query to be run in the stack.

Example

var query = datastore.getNextQuery();

getStackLength()

A function used to get the length of the stack.

Returns The length of the stack.

Example

var stackLength = datastore.getStackLength();

removeAllQueries()

A function used to remove all of the queries from the stack. This function acts in a similar manner to the getAllQueries function, but empties the stack as well as retrieving all of the queries currently in the stack.

Returns An array containing all of the queries that were removed from the stack.

Example

var queries = datastore.removeAllQueries();

removeNextQuery()

A function used to the next query from the stack, based on the FIFO model. This function acts in a similar manner to the getNextQuery function, but removes the next query from the stack as well as retrieving it.

Returns The query object that was removed from the stack.

Example

var query = datastore.removeNextQuery();

runAllQueries(callback)

A function used to execute all of the queries from the stack against the Datastore.

Parameters

• callback(error, result) - A callback that returns any errors that occured while trying to execute the queries stored in the stack or null, and an array individual arrays of results corresponding to each query (or null if there were errors).

Example

datastore.runAllQueries(function(error, result) {
    if(!error){
        // do something
    }
});

runNextQuery(callback)

A function used to execute the next query from the stack against the Datastore.

Parameters

• callback(error, result) - A callback that returns any errors that occured while trying to execute the queries stored in the stack or null,

Example

datastore.runNextQuery(function(error, result) {
    if(!error){
        // do something
    }
});

runQuery(query, callback)

A function used to execute the inputted query against the Datastore.

Parameters

• query - A query object to execute.
• callback(error, result) - A callback that returns any errors that occured while trying to execute the queries stored in the stack or null,

Example

var query = datastore.createQuery('Animal');

datastore.runQuery(query, function(error, result) {
    if(!error){
        // do something
    }
});

License

MIT

Fork away!

}