Charting libraries that use XML files to define charts use a array based structure to enable users settings arbitrary parameters. The expected array structure is described here.

Parameters

To allow the definition of any XML structure the array supports the following parameters:

#attributes

optional parameter for attribute setting. When present it's an array where each key is the attribute name and each value is the attribute value.

#cdata

sets the CDATA content of the tag. Each tag can have one #cdata or one #value or none of the both but can't have both.

#children

it holds the tags nested inside the current tag. If present must be an array with the tags that go inside the current tag. It's optional and, when present, it's always an array of arrays as it must support several tags inside it.

#id

sets the tag ID. This is the only mandatory parameter.

#value

sets the text content of the tag. For tags without content is can be ommited. For nested tags see #children.

To remove a tag defined by the charting library the user must pass a tag with the id to be removed and the #value parameter with the NULL value.

Examples

Here is a rather complete example. Remember that the only mandatory parameter is #id. Observe that the main array and each #children array is an array of arrays.

<?php
$canvas->settings = array(
  array(
    '#id' => 'value',
    '#value' => $this->encode_for_xml($val),
    '#attributes' => array(
      'xid' => 13,
  ),
  array('#id' => 'js_enabled', '#value' => 'false'),
  array(
    '#id' => 'axes',
    '#children' => array(
      array(
        '#id' => 'y_left',
        '#children' => array(array(
          '#id' => 'logarithmic',
          '#value' => 'true')),
      ),
      array('#id' => 'show', '#cdata' => '{title}: {value}%'),
    ),
  )),
);

The above code results in the following settings file:

<?xml version="1.0" encoding="utf-8"?>
<settings>
  <value xid="13">STRING_REPRESENTATION_OF_ENCODED_VALUE_OF$val</value>
  <js_enabled>false</js_enabled>
  <axes>
    <y_left>
      <logarithmic>true</logarithmic>
    </y_left>
    <show><![CDATA[{title}: {value}%]]></show>
  </axes>
</settings>

Observations

To guarantee complete flexibility no treatment is made in the contents of any paramters: #id, #value etc. Any enconding, case transformation or else must be done by the user before passing the data to each charting library.

#cdata content receive CDATA's prefix and suffix:

<![CDATA[

]]>