##Espresso Logic Espresso Logic is the fastest way to create REST APIs with your data. You can join data across multiple data sources, write declarative rules, and define granular security for an API that deploys in the time it takes to scan the schema. For more information about this SDK, please visit our doc center.
The SDK library is installed as we might expect, from a simple npm install command:
npm install espressologic
Connecting to an existing project is done via the espressologic.connect() method. Here we are connecting to a sample API which is available as a sandbox for exploring the basics:
var espressologic, api;
espressologic = require('espressologic');
//via a username and password
api = espressologic.connect('https://eval.espressologic.com/rest/livedemo/demo/v1', 'demo', 'Password1');
//or with an API key
api = espressologic.connect('https://eval.espressologic.com/rest/livedemo/demo/v1', 'readonly');Espresso builds an API around the tables and relationships it finds in your database. Once connected, your project endpoints are accessible in an easy to use format:
var espressologic, api;
espressologic = require('espressologic');
//API endpoints follow a simple structure: {projectUrl}/{databasePrefix}:{tableName}
//a full endpoint might look like this "https://eval.espressologic.com/rest/livedemo/demo/v1/customer"
api = espressologic.connect('https://eval.espressologic.com/rest/livedemo/demo/v1', 'demo', 'Password1');
var customers;
customers = api.endpoint('customer');
customers.get().then(function (data) {
console.log(data); //an array of objects from our customers table
});The customers.get() method refers to the http request method, and PUT/POST/DELETE requests will look very similar (though, for these requests, we invite you to register for an account @ Espresso Logic).
var customers, newCustomer;
customers = api.endpoint('/customers');
alphaCustomer = {
name: "Alpha",
credit_limit: "1234"
};
//POST
customers.post(alphaCustomer, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});
//GET
customers.get().then(function (data) {
console.log(data); //an array which will now include customer: Alpha
//objects returned include metadata specific to each record,
//the most useful to us here is the endpoint href
var alphaEndpoint = espressologic.endpoint(data[0]['@metadata'].href);
//PUT
data[0].name = 'Alpha Updated';
alphaEndpoint.put(data[0]).then(function(txSummary) {
console.log(txSummary);
});
//DELETE
alphaEndpoint.delete(data[0]).then(function(txSummary) {
console.log(txSummary);
});
});
Using Node.js to Create a Database connection, create a Resource, and Add Reactive Logic (Metadata API)
//API endpoints follow a simple structure: {projectUrl}/{databasePrefix}:{tableName} to retrieve data from your service
//a full endpoint might look like this "https://eval.espressologic.com/rest/livedemo/demo/v1/customer"
//this is the meta api used to create and manage the creation of a project, database, resources, and rules
//use the servername and password sent to you when you created a new appliance or cloud account.
var espressologic = require('./EspressoLogicSDK');
var serverName = 'http://{myservername}/rest/abl/admin/v2';
var userName = 'admin';
var password = 'mypassword';
var api = espressologic.connect(serverName, userName, password);
//create or find your project ID and set the global value
var projects = api.endpoint('AllProjects?pagesize=100');
projects.get().then(function(data){
for(var idx in data){
console.log('ProjectName: '+data[idx].name + " Project ident "+data[idx].ident);
}
});
var project_ident = 1001;
var params = {};
// dbasetype_ident
// 1 MySQL MySQL Database
// 2 Oracle Oracle (Thin driver)
// 3 SQLServer(jTDS) Microsoft SQL Server(jTDS - obsolete)
// 5 SQLServer Microsoft SQL Server
// 6 AzureSQL Windows Azure SQL
// 7 NuoDB (beta) NuoDB - beta
// 8 PostgreSQL Postgres (beta)
//create a new connection to our project
var dbschema = api.endpoint('/DbSchemas');
var json = {"name":"My New database","url":"jdbc:mysql://<hostname>/<db-name>","user_name":"jdoe","active":false,"project_ident":project_ident,"dbasetype_ident":1}
dbschema.post(json, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});
//create a new resource
var resource = api.endpoint('/AllResources');
var json = {"resource_type_ident":1,"apiversion_ident":project_ident,"name":"MyNewCustomerResource","prefix":"demo","table_name":"customer","is_collection":"Y"};
resource.post(json, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});
//add child resource - using root_ident from prior txSummary - remember to add join as childColumn = [parentColumn]
var subresource = api.endpoint('/AllResources');
var json ={"apiversion_ident":project_ident,"resource_type_ident":1,"name":"NewChildResource","prefix":"demo","table_name":"orders", "join_condition": "customerID=[customerId]","is_collection":"Y","root_ident":1086,"container_ident":1086};
subresource.post(json, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});
// ruletype_ident
// 1 sum sum child attr into parent
// 2 count count child attr into parent
// 3 formula formula using table & parent attributes
// 4 parent copy non-cascaded parent value
// 5 validation multi-attribute validation
// 6 commit validation multi-attribute validation after all rows
// 7 event extensible event
// 8 early event extensible event before rule execution
// 9 commit event extensible event after all rows
// 11 minimum replicate the minimum value from a child attribute
// 12 maximum replicate the maximum value from a child attribute
// 13 managed parent create a parent if it does not exist//declare validation and derivation rules.
//add SUM on Customer
var sumrule = api.endpoint('/AllRules');
var json = {"ruletype_ident":1,"entity_name":"demo:customer","project_ident":project_ident,"attribute_name":"balance","rule_text1":"purchaseorderList","rule_text3":"amount_total","active":true};
sumrule.post(json, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});
//Add Validation Check on Credit Limit
var validationRule = api.endpoint('/AllRules');
var json = {"ruletype_ident":5,"entity_name":"demo:customer","attribute_name": null,"project_ident":project_ident,"prop4": "javascript","rule_text1": "return row.balance <= row.credit_limit;","rule_text2": "Customer {name}'s balance: {balance|#,##0.00} exceeds their credit limit: {credit_limit|#,##0.00}","active":true};
validationRule.post(json, params).then(function (txSummary) {
console.log(txSummary); //an array of objects updated
});