AppML Data Sources
A model file doesn't hold the data itself - it describes where the data comes from and which actions are allowed to touch it, from a simple static list to a full database table.
What a Model Describes
The model referenced by appml-data is a JSON configuration, not a data dump. Its job is to name a data source and define the actions available against it, so the template never has to know whether that source is a static file or a live database.
- An identifier for the data source (for example, a database and table name)
- The fields that make up each record
- One or more named actions - commonly list, and optionally insert, update, and delete - each describing how that operation reaches the data source
Example: a database-backed model
{
"database": "companydata",
"table": "employees",
"actions": [
{ "name": "list", "sql": "select * from employees" },
{ "name": "insert", "sql": "insert into employees (firstname,lastname,department) values (@firstname,@lastname,@department)" },
{ "name": "update", "sql": "update employees set firstname=@firstname, lastname=@lastname, department=@department where id=@id" },
{ "name": "delete", "sql": "delete from employees where id=@id" }
]
}Static Files as a Data Source
A model can also point at data that's simply embedded as a plain JSON array, with just a list action and no insert/update/delete defined. That's enough for read-only pages, demos, or working out a template's layout before any real persistence is wired up.
Example: a static model
{
"records": [
{ "name": "Notebook", "price": 3.5 },
{ "name": "Pen", "price": 1.2 },
{ "name": "Backpack", "price": 25 }
],
"actions": [
{ "name": "list" }
]
}Controllers and Actions covers how each action in the model actually reaches server-side logic.
Exercise: AppML Data
What does the appml-data attribute specify?
