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evolutility-server-node

0.7.0 • Public • Published

Evolutility-Server-Node

Model-driven RESTful backend for CRUD and more, using Node.js, Express, and PostgreSQL.

Evolutility-Server-Node provides a set of generic REST endpoints for CRUD (Create, Read, Update, Delete) and simple charts. These views can adapt to different data structures according to their models.

For a matching model-driven Web UI, use Evolutility-UI-React or Evolutility-UI-jQuery.

Table of Contents

  1. Installation
  2. Setup
  3. Configuration
  4. Models
  5. API
  6. License

Installation

Download or clone from GitHub.

# To get the latest stable version, use git from the command line. 
git clone https://github.com/evoluteur/evolutility-server-node

or use the npm package:

# To get the latest stable version, use npm from the command line. 
npm install evolutility-server-node

Setup

After installing Evolutility-Server-Node, follow these steps:

  1. Create a PostgreSQL database.

  2. In the file config.js set the PostgreSQL connection string and the schema name to access your new database.

  3. Maybe, also change other config options in the same file.

  4. In the command line type the following:

# Install dependencies 
npm install
 
# Create sample database w/ demo tables 
node js/setup/database.js
 
# Run the node.js server 
npm start
 

Note: The database creation and population scripts are logged in the files "evol-db-schema-{datetime}.sql" and "evol-db-data-{datetime}.sql".

In a web browser, go to the url http://localhost:2000/api/v1/evolutility/todo.

Configuration

Configuration options are set in the file config.js.

Option Description
apiPath Path for REST API (i.e.: "/api/v1/evolutility/").
apiPort Port for REST API (i.e.: 2000).
connectionString DB connection string (i.e.: "postgres://evol:love@localhost:5432/evol").
schema DB schema name (i.e.: "evolutility").
pageSize Number of rows per page in pagination (default = 50).
lovSize Maximum number of values allowed for form dropdowns (default = 100).
csvSize Maximum number of rows in CSV export (default = 1000).
csvHeader CSV list of labels for CSV export
consoleLog Log SQL statements to console.
wComments Allow for user comments.
wRating Allow for user ratings.
wTimestamp Timestamp columns u_date and c_date w/ date of record creation and last update.

Models

To be accessible by the REST API, each database table must be described in a model. Models contain the name of the driving table and the list of fields/columns present in the API.

Object

Property Description
id Unique key to identify the entity (used as API parameter).
table Driving database table name (there are secondary tables for fields of type "lov").
pKey Name of the Primary key column (single column of type serial). Default to "id". In the data the key is always called "id".
fields Array of fields.
titleField Field id for the column value used as record title.
searchFields Array of field ids for fields used to perform searches.

Field

Property Description
id Unique key for the field (can be the same as column but doesn't have to be).
column Database column name for the field.
lovTable Table to join to for field value (only for fields of type "lov").
lovColumn Column name (in the lovTable) for field value (only for fields of type "lov").
lovIcon Set to True to include icon with LOV items (only for fields of type "lov").
object Model id for the object to link to (only for fields of type "lov").
type Field type is not a database column type but more a UI field type. Possible field types:
  • boolean
  • date
  • datetime
  • decimal
  • document
  • email
  • image
  • integer
  • lov (list of values)
  • money
  • text
  • textmultiline
  • time
  • url
required Determines if the field is required for saving.
readonly Prevents field modification.
inMany Determines if the field is present (by default) in lists of records.
max, min Maximum/Minimum value allowed (only applies to numeric fields).
maxLength, minLength Maximum/Minimum length allowed (only applies to text fields).
unique Values must be unique (not implemented yet).
noCharts Forbids charts on the field.
deleteTrigger Deleting records in the lovTable will trigger a cascade delete (this property is only used while creating the database).

Collection

Multiple Master-Details can be specified with collections.

Property Meaning
id Unique key for the collection.
table DB Table to query.
column Column in the detail table to match against id of object.
object Model id for the object to display (optional).
order "asc"/"desc" for sorting by the first field in fields.
fields Array of fields. Fields in collections do not need all properties of Fields in objects.

Example of collection in Wine cellar.

Sample model

Below is the model for a To-Do app.

module.exports = {
    id: "todo",
    table: "task",
    titleField: "title",
    searchFields: ["title", "duedate", "description"],
    fields: [
        {
            id: "title", 
            column: "title", 
            type: "text", 
            required: true, 
            inMany: true
        },
        {
            id: "duedate", 
            column: "duedate", 
            type: "date", 
            inMany: true
        },
        {
            id: "category", 
            column: "category_id", 
            type: "lov", 
            lovTable: "task_category",
            inMany: true
        },
        {
            id: "priority", 
            column: "priority_id", 
            type: "lov", 
            lovTable: "task_priority", 
            required: true, 
            inMany: true
        {
            id: "complete", 
            column: "complete", 
            type: "boolean", 
            inMany: true
        },
        {
            id: "description", 
            column: "description", 
            type: "textmultiline"
        }
    ]
};
 

More sample models: Address book, Restaurants list, Wine cellar, Graphic novels inventory.

API

Evolutility-Server-Node provides a generic RESTful API for CRUD (Create, Read, Update, Delete) and more. It uses Node.js, Express and PostgreSQL. The API is inspired from PostgREST.

When running Evolutility-Server-Node locally, the url for the "todo" app is http://localhost:2000/api/v1/evolutility/todo.

Requesting Information

Get One

Gets a specific record by ID.

GET /<model.id>/<id>

GET /todo/12

Get Many

Gets a list of records.

GET /<model.id>

GET /todo

Filtering

You can filter result rows by adding conditions on fields, each condition is a query string parameter.

GET /<model.id>/<field.id>=<operator>.<value>

GET /todo?title=sw.a
GET /todo?priority=in.1,2,3

Adding multiple parameters conjoins the conditions:

todo?complete=0&duedate=lt.2018-12-24

For each field a sub-set of the operators below will be supported by the API (depending field types).

Operator Meaning Example
eq equals /todo?category=eq.1
gt greater than /todo?duedate=gt.2019-01-15
lt less than /todo?duedate=lt.2019-01-15
gte less than or equal /todo?duedate=gte.2019-01-15
lte less than or equal /todo?duedate=lte.2019-01-15
ct contains /todo?title=ct.e
sw start with /todo?title=sw.a
fw finishes with /todo?title=fw.z
in one of a list of values /todo?priority=in.1,2,3
0 is false or null /todo?complete=0
1 is true /todo?complete=1
null is null /todo?category=null
nn is not null /todo?category==nn

Searching

You can search for a specific string across multiple fields at once with the "search" parameter. The list of fields to be searched is specified with "searchFields" in the model (if unspecified, text fields flagged with "inMany" for list view will be used).

GET /<model.id>/search=<value>

GET /todo?search=translation

Ordering

The reserved word "order" reorders the response rows. It uses a comma-separated list of fields and directions:

GET /<model.id>?order=<field.id>.<asc/desc>

GET /todo?order=priority.desc,title.asc

If no direction is specified it defaults to ascending order:

GET /todo?order=duedate

Limiting and Pagination

The reserved words "page" and "pageSize" limits the response rows.

GET /<model.id>?page=<pageindex>&pageSize=<pagesize>

GET /todo?page=0&pageSize=50

Formatting

By default all APIs return data in JSON format. This API call allows to request data in CSV format (export to Excel). This feature is using csv-express.

GET /<model.id>?format=csv

GET /todo?format=csv

Notes: In the returned data every object has an extra property "_full_count" which indicate the total number of records in the query (before limit).

Updating Data

Record creation

To create a row in a database table post a JSON object whose keys are the names of the columns you would like to create. Missing keys will be set to default values when applicable.

POST <model.id> {<data>}

POST /todo
{ title: 'Finish testing', priority: 2}

Even though it is a "POST", the request also returns the newly created record. It is not standard but it saves the UI a subsequent call.

Update

PATCH or PUT can be used to update specific records.

PATCH /<model.id>/<id>

PATCH /todo/5
{ title: 'Finish testing', priority: 2}
PUT /<model.id>/<id>

PUT /todo/5
{ title: 'Finish testing', priority: 2}

Notes: The request returns the updated record. It is not standard but it saves the UI a subsequent call.

Deletion

Simply use the DELETE verb with the id of the record to remove.

DELETE /<model.id>/<id>

DELETE /todo/5

Extras endpoints

In addition to CRUD, Evolutility-Server-Node provides a few endpoints for Charts, Lists of values, file upload, and API discovery.

Discovery

Returns the list of active Objects and their "GET" APIs.

GET /

Note: This end-point can be disabled in the configuration with {apiInfo: false}.

Charts

For charts data, it is possible to get aggregated data for field of types lov, boolean, integer, decimal, and money. Use the attribute "noCharts" to exclude a field from Charts.

GET /<model.id>/chart/<field id>

GET /todo/chart/category

Stats

Returns the total count, and the min, max, average, and total for numeric fields in the model.

GET /<model.id>/stats

GET /todo/stats

Lists of Values

Dropdown fields in the UI (field.type="lov" in the model) have a REST endpoint to get the list of values (used for dropdowns in the UI).

GET /<model.id>/lov/<field.id>

GET /todo/lov/category

File upload

This endpoint lets you upload a file. The current (naive) implementation simply saves the file on the file server in a folder named like the model id (inside the folder specified by the option "uploadPath" in config.js).

POST /<model.id>/upload/<id>

POST /comics/upload/5

With query parameters: file and "field.id".

Nested collections

If the model has collections defined, they can be queried with this end-point.

GET /<model.id>/collec/<collection.id>?id=<id>

GET /winecellar/collec/wine_tasting?id=1

Schema tables and columns

These endpoints query for the database structure (rather than the data), and returns lists of tables and columns.

List of schema tables (props: table, type, readOnly).

GET /db/tables

List of columns (props: column, type, required) for a specified table.

GET /db/<table>/columns

GET /db/contact/columns
GET /db/task/columns

API version

This endpoint gets the API version (as specified in the project's package.json file).

GET /version

License

Copyright (c) 2019 Olivier Giulieri.

Evolutility-Server-Node is released under the MIT license.

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npm i evolutility-server-node

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161

version

0.7.0

license

MIT

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github.com

repository

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