S3XRC | S3 RESTful API | s3_rest_controller

s3_rest_controller

Introduction

The so-called REST Controller (function s3_rest_controller()) is a helper function to easily apply the RESTful API of the S3Resource class to your controller.

s3_rest_controller does:

• parse and execute the incoming HTTP request on the specified resource
• populate and hand-over view variables
• choose and set the response view template (response.view)

Using s3_rest_controller, a basic RESTful controller for the pr_image table can look like:

def image():

    """ RESTful CRUD controller """

    return s3_rest_controller("pr", "image")

This exposes all standard URLs and methods for this table, including:

• interactive create, read, update, delete and list views
• non-interactive data export/import (GET/POST/PUT/DELETE) in multiple formats

Basic Syntax

output = s3_rest_controller(prefix, resourcename)

• prefix is the application prefix of the resource
• resourcename is the name of the resource (without prefix)

• output contains the result of the request and can be returned from the controller as-is
  • in interactive view formats, this is a dict of view variables

Basic Options

Redirection

Callbacks

Pagination

The default pagination method is server-side (SSPag), meaning, in list views the client will receive only the first of the available rows, and then retrieve more rows as needed by subsequent Ajax calls.

In contrast to that, in client side pagination (CSPag) mode all rows of a list are retrieved and send to the client at once, while the client arranges them in pages. This can though be a huge data set which takes a long time to extract it, which can be unefficient when the user only needs to see the first 20 rows to find what he's looking for.

However, some tables may by their nature only have one or few rows, and then server-side pagination is not needed. In these cases, the respective controller can turn it off by:

response.s3.no_sspag=True

View Control

Default View

Custom View

Additional View Variables

In interactive view formats, any additional named arguments in the s3_rest_controller argument list will be added to the view variables:

output = s3_rest_controller(prefix, resourcename, **attr)

• attr: additional view variables

• any callable argument will be invoked with the S3Request as first and only argument, and its return value will be added to the view variables
• any non-callable argument will be added to the view variables as-is
• any argument that gives None will remove this key from the view variables

A typical use-case is rheader:

def my_rheader(r):
  if r.interactive and r.component:
    # Code producing the rheader...
    return rheader
  else:
    return None

output = s3_rest_controller(prefix, name, rheader=my_rheader)

If my_rheader(r) gives something else than None, then this value is added as rheader to the view variables.

Advanced Options

Pre-Process

Post-Process

Method Handlers

Custom Methods

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