Explanation of Cargo Usage in Template:Asset

This page documents how and why Cargo is used in Template:Asset.

It exists as long-term reference documentation and is intended to be read slowly and re-read over time.

Purpose of This Document

Cargo configuration is often difficult to understand because:

it mixes schema definition and data storage
it uses parser functions that look similar but behave very differently
errors are often silent

This document explains, line by line, the Cargo-related parts of Template:Asset, without involving Page Forms, JavaScript, or Lua.

Big Picture

Cargo is used in Template:Asset for exactly two purposes:

Declare the data structure (schema)
Store data when a page is saved

Cargo does NOT:

control page layout
control page editing
control file uploads
control automation

Cargo only stores and retrieves structured data.

Cargo Declaration Section

In Template:Asset, the Cargo declaration appears inside a <noinclude> section:

<noinclude>
{{#cargo_declare:
 |_table=Assets
 |Code=Page
 |Label=String
 |Chapter=Page
 |Place=Page
 |Organisation=Page
 |Sequence=Integer
 |File=String
 |OriginalFilename=String
 |Parent=Page
 |AssetType=Page
 |Description=Text
 |Notes=Text
}}
</noinclude>

This section defines the structure of the Cargo table.

Why cargo_declare Is Inside <noinclude>

<noinclude> means:

The declaration is part of the template definition
It is NOT included when the template is transcluded into a page

Why this matters:

The Cargo table is declared once
It is not redeclared every time an Asset page is viewed
Prevents schema duplication and errors

Important rule: cargo_declare MUST always be inside <noinclude>.

The Cargo Table Name

|_table=Assets

What it does:

Defines the name of the Cargo table
All Asset records are stored in this table

Why it matters:

Table name is global and permanent
Changing it later breaks all queries

In Asset v2, the table name Assets is locked.

Field Definitions

Each line defines one field (column) in the table.

Example:

|Label=String

Meaning:

Field name: Label
Field type: String

Cargo types define how data is stored and queried.

Explanation of Field Types Used

Page

Example:

|Chapter=Page

What it means:

Stores a wiki page reference
Enables linking and page-based queries

Used for:

Chapter
Place
Organisation
Parent
AssetType
Code (page name)

String

Example:

|OriginalFilename=String

What it means:

Stores plain text
No page linkage
No namespace assumptions

Used for:

Original filenames
File names
Labels

Important: File is stored as String on purpose to avoid Page-type constraints.

Integer

Example:

|Sequence=Integer

What it means:

Stores numeric values
Enables numeric comparison and MAX() queries

Used for:

Sequence numbering

Text

Example:

|Description=Text

What it means:

Stores long free-form text
No length limit

Used for:

Descriptions
Notes

Cargo Store Section

Below the declaration, Template:Asset contains:

{{#cargo_store:
 |Code={{FULLPAGENAME}}
 |Label={{{Label|}}}
 |Chapter={{{Chapter|}}}
 |Place={{{Place|}}}
 |Organisation={{{Organisation|}}}
 |Sequence={{{Sequence|}}}
 |File={{{File|}}}
 |OriginalFilename={{{OriginalFilename|}}}
 |Parent={{{Parent|}}}
 |AssetType={{{AssetType|}}}
 |Description={{{Description|}}}
 |Notes={{{Notes|}}}
}}

This section is executed every time an Asset page is saved.

What cargo_store Does

#cargo_store:

Takes values from template parameters
Writes them into the Cargo table
Updates existing rows automatically

Important:

It does NOT create pages
It does NOT validate input
It does NOT control editing

Why Code Uses FULLPAGENAME

|Code={{FULLPAGENAME}}

Meaning:

Stores the page name of the Asset
Example:

 Asset:CH03-BER-0007

Why this matters:

The page name is the authoritative identifier
Cargo rows can always be linked back to their page

This field must never change after creation.

Why Template Parameters Use Triple Braces

Example:

|Label={{{Label|}}}

Meaning:

Reads the value passed to the template
Uses empty default if not provided

Triple braces are standard MediaWiki template syntax and are required.

Important Reminder

Cargo does NOT enforce immutability.

Rules such as:

“Identifier must not change”
“OriginalFilename is immutable”

are enforced by:

Page Forms configuration
JavaScript
user discipline
server-side extensions

Cargo only stores what it is given.

Mental Model to Keep

You can safely remember:

cargo_declare = table definition
cargo_store = data write operation
Template parameters = data source
Cargo does not control behavior

Status

This document is stable reference documentation.

It exists to support long-term understanding and memory retention.