BluePrint: Templates

Introduction

Templates allow selecting alternate configuration sets.

This allows a separation between Core Code & Settings/Custom Code.

This helps prevent merge conflicts between different deployment branches & hence reduces the risk of forking.

Requirements

See Use-Cases

Use-Cases

End-User wishing to trial the System

The end-user would like to download & run immediately with the minimimum of up-front configuration possible - the defaults should be sufficient to get started with.

If they must select between alternate options then they'd definitely want this to be done through the web browser.

• perhaps the most useful would be a single web page with a list of Templates to choose from, with a big button to say 'OK' to proceed with the default.

Once they've played around some & wish to customise it, then they would like to be able to configure options via WebSetup.

Once they decide to go into production, it would be really useful to be able to save all the settings they've made in their local instance to a file & then use this file to configure their server instance. This could include population of lookup lists being saved as CSVs and then compressing these into a single file to be uncompressed on the server.

Deployer

The deployer wants to be walked through the different settings...ideally through a WebSetup Wizard, however they're OK at doing this through a text file or CLI prompts if-required.

They want to minimise the number of interrupts during the setup process - i.e. they would like to run a single script to download/install all the software & then run through a single set of configuration options. The current supported installation scripts do this reasonably well, e.g. InstallationGuidelines/Linux/Server/CherokeePostgreSQL

Developer/Tester

The developer/tester would like to be able to quickly move their system between different configuration options. This would typically happen as part of their 'clean' script, so could be done via the CLI

They would like to distinguish between the settings which relate to the profile template from the settings which are about their machine instance (Debug, SMTP, Database, API Keys, etc)

They would like to select between prepopulate options when using a single configuration template. e.g. IFRC 000_config.py can be used with IFRC, ["IFRC", "IFRC_Train"] or ["IFRC", "IFRC_Train", "IFRC_Demo"], but we don't want to have to maintain 3x 000_config.py files.

Trunk Maintainer

The old deployment_templates/000_config.py always had regular merge conflicts with deployment branches, so separating these into separate template folders should improve things.

We would like to minimise the differences between the different templates so all the non-default ones should only enable what they need in order to minimise maintenance.

Design

DeveloperGuidelines/Templates

Future extensions

These are proposed extensions which need refining:

Template Inheritance

• Allow components of templates to be re-used by one another

Message Parser:

• private/templates/<template>/parser.py
  • imported into modules/s3/s3msg.py

Tasks:

• private/templates/<template>/tasks.py
  • imported into models/tasks.py

Theme:

• controllers/default.py index()

Menus:

• private/templates/<template>/menus.py
  • subclasses modules/s3menus.py to allow overrides
• private/templates/<template>/layouts.py
  • subclasses modules/s3layouts.py to allow overrides
• models/01_menu.py should no longer be required

Fields:

• private/templates/<template>/fields.py
  • includes any local overrides to field labels/readable/writable/DAL-level required
• modules/s3/s3fields.py
  • S3Field to subclass Field to read settings from fields.py

Implementation

Implmentation Steps for the next phase:

• Load layouts.py & menus.py from private/templates/<template>

References

• DeveloperGuidelines/Templates
• DeveloperGuidelines/PrePopulate
• BluePrint/WebSetup
• ​Profile Layer
• ​Profile Templates Plan
• ​Splitting up CSS into separate files

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BluePrints