{data}

Turns its content - JSON, XML, YAML, CSV, a list or a range - into a named data set for a later tag to iterate.

Variables and stores Either form

Syntax 

{data 'name'} ... {/data}
{data 'name', type='csv'} ... {/data}
{data 'name', source}
{data} ... {/data 'name'}

Parameters

name
The name the data is kept under; {name} ... {/name} (or {data:name}) iterates it. Not the name of a built-in or application tag.
source
Optional, when there is no content: the data as a value - '1..5', '["a","b"]' - or a field holding it.

Options

type
The format of the content - json, xml, yaml, csv, list, range ... - when its first characters do not tell.

Description

{data 'name'} ... {/data} reads its content as data and keeps it under that name; it prints nothing. A later {name} ... {/name} iterates it like any page array - fields, properties, the handling options (sort, where, first ...) - and so do data='name' on another tag, {data:name}, {tree} and the lookup pipe.

Formats

The format is recognised from the content itself:

  • JSON - starts with [ or {. An array of objects gives rows with fields; a plain array gives values, read with {$name}.
  • XML - starts with <. The elements under the root are the rows, their attributes and child elements the fields.
  • YAML - starts with ---, or with a - item or key: value line. It needs PHP's yaml extension.
  • A list - ('a', 'b', 2 * 3) in parentheses: every element is evaluated as an expression.
  • A range - 1..10 or a..z.
  • CSV - anything else of several lines: the first line names the fields, each further line is a row.

When the start does not tell, type='csv' (or another format) says it. A one-line name of a file in the application's _data/ directory reads that file.

Other forms

Without content, a second parameter is the source: {data 'steps', '1..5'}. A value from a field there is data, never template: a field holding a parenthesised list is refused, since its elements would run as expressions. With the name on the closing tag - {data} ... {/data 'name'} - the content is rendered first and the result read as data, so fields and tags inside it are resolved.

Content with braces - JSON objects - is read as written: a JSON object in the content is not taken for a tag. Under the strict syntax check a {data} without a name is an error, and so is a name that is already a built-in or application tag, since {name} would never reach the store.

Examples

JSON rows

An array of objects becomes rows with fields, iterated by the name it was given.

Templateexamples/data/1-json.pad 
{data 'dataPlanets'}
[
  { "name": "Mercury", "moons": 0 },
  { "name": "Earth",   "moons": 1 },
  { "name": "Mars",    "moons": 2 }
]
{/data}
<ul>
{dataPlanets}
  <li>{$name}: {$moons} {echo $moons eq 1 ? 'moon' : 'moons'}</li>
{/dataPlanets}
</ul>
Resultopen alone
  • Mercury: 0 moons
  • Earth: 1 moon
  • Mars: 2 moons

CSV and XML

The first CSV line names the fields; XML elements under the root are the rows, attributes the fields.

Templateexamples/data/2-csv-xml.pad 
{data 'dataPrices'}
fruit,price
Apple,0.40
Pear,0.55
{/data}
{data 'dataStock'}
<stock>
  <item fruit="Apple" boxes="12"/>
  <item fruit="Pear" boxes="3"/>
</stock>
{/data}
<p>{dataPrices}{$fruit} costs {$price}. {/dataPrices}</p>
<p>{dataStock}{$fruit}: {$boxes} boxes. {/dataStock}</p>
Resultopen alone

Apple costs 0.40. Pear costs 0.55.

Apple: 12 boxes. Pear: 3 boxes.

Ranges, lists and a source parameter

A range, an evaluated list, and data given as the second parameter instead of content.

Templateexamples/data/3-list.pad 
{data 'dataLetters'}a..f{/data}
{data 'dataSums'}(1 + 1, 2 * 3, 10 - 7){/data}
{data 'dataSteps', '1..4'}
<p>{dataLetters}{$dataLetters} {/dataLetters}</p>
<p>{dataSums}{$dataSums} {/dataSums}</p>
<p>{dataSteps}step {$dataSteps}{notLast@dataSteps}, {/notLast@dataSteps}{/dataSteps}</p>
Resultopen alone

a b c d e f

2 6 3

step 1, step 2, step 3, step 4

See also

  • {content} Keeps a piece of template under a name instead of printing it, for a later {name} to render.
  • {bool} Reduces its content or a value to TRUE or FALSE and keeps it under a name, for a later {name} to test.
  • {set} Assigns one or more variables, as globals that outlive the level the tag stands in.
  • {tree} Renders a tree of rows: its body for every row, and {recurse} renders it again for the row's children.
  • {count} Renders its content only when a named data set or page array holds at least one element.