= 自定义传票字段 =
Trac支持向传票模型中添加自定义的字段. 使用自定义的字段, 你可以向传票中添加项目特有的属性.

== 配置 ==
自定义传票字段是在[wiki:ZhTracIni trac.ini]文件中配置的. 所有字段定义应位于`[ticket-custom]`段中.

字段定义的语法:
{{{
 FIELD_NAME = TYPE
 (FIELD_NAME.OPTION = VALUE)
 ...
}}}

=== 可用字段类型和选项 ===
 * '''text''': 简单文字字段(一行).
   * label: 描述性标签.
   * value: 默认值.
   * order: 排序位置.(在表单中决定与其他定制字段的相对位置)
 * '''checkbox''': 复选框(布尔值).
   * label: 描述性标签.
   * value: 默认值 (0 或 1).
   * order: 排序位置.
 * '''select''': 下拉选择框(值的列表).
   * label: 描述性标签.
   * options: 值的列表, 用'''|'''分隔.
   * value: 默认值 (条目号, 从0开始).
   * order: 排序位置.
 * '''radio''': 单选按钮, 实质上跟'''select'''一样.
   * label: 描述性标签.
   * options: 值的列表, 用'''|'''分隔
   * value: 默认值 (条目号, 从0开始).
   * order: 排序位置.
 * '''textarea''': 多行文本字段.
   * label: 描述性标签.
   * value: 默认文本.
   * cols: 列宽.
   * rows: 行高.
   * order: 排序位置.

=== 配置范例 ===
{{{
[ticket-custom]

test_one = text
test_one.label = Just a text box

test_two = text
test_two.label = Another text-box
test_two.value = Just a default value

test_three = checkbox
test_three.label = Some checkbox
test_three.value = 1

test_four = select
test_four.label = My selectbox
test_four.options = one|two|third option|four
test_four.value = two

test_five = radio
test_five.label = Radio buttons are fun
test_five.options = uno|dos|tres|cuatro|cinco
test_five.value = 1

test_six = textarea
test_six.label = This is a large textarea
test_six.value = Default text
test_six.cols = 60
test_six.rows = 30
}}}

'''注意''': 要使`select`类型的字段可输入文字, 需要在`fieldname.options`选项中加上前导的`|`

=== 与报表相关的自定义字段 ===
自定义报表字段存储在`ticket_custom`表中, 而不是在`ticket`表中. 因此, 要在报表中显示自定义字段的值, 你将需要联合2个表. 让我们用自定义字段`progress`举例说明.

{{{
#!sql
SELECT p.value AS __color__,
   id AS ticket, summary, owner, c.value AS progress
  FROM ticket t, enum p, ticket_custom c
  WHERE status IN ('assigned') AND t.id = c.ticket AND c.name = 'progress'
AND p.name = t.priority AND p.type = 'priority'
  ORDER BY p.value
}}}
'''注意''' 这将仅仅显示有progress字段的传票, 跟'''显示所有传票不同'''. 如果你创建此自定义传票字段在你的已有传票''之后'', 这些传票将没有此字段, 因此它们将不会出现在查询结果中. 如果你返回并修改这些传票, 将生成此字段, 也就会出现在查询结果中. 如果这是你想要的结果, 那你做到了.

然而, 如果你想显示所有传票(有或没有progress字段), 你需要在查询中为每个自定义字段使用`JOIN`.
{{{
#!sql
SELECT p.value AS __color__,
   id AS ticket, summary, component, version, milestone, severity,
   (CASE status WHEN 'assigned' THEN owner||' *' ELSE owner END) AS owner,
   time AS created,
   changetime AS _changetime, description AS _description,
   reporter AS _reporter,
  (CASE WHEN c.value = '0' THEN 'None' ELSE c.value END) AS progress
  FROM ticket t
     LEFT OUTER JOIN ticket_custom c ON (t.id = c.ticket AND c.name = 'progress')
     JOIN enum p ON p.name = t.priority AND p.type='priority'
  WHERE status IN ('new', 'assigned', 'reopened')
  ORDER BY p.value, milestone, severity, time
}}}

特别注意此处的`LEFT OUTER JOIN`.

=== 更新数据库 ===

如上所述, 在自定义字段被定义之前创建的所有传票都没有此字段的值. 这里有一些SQL(用SQLite测试过), 可以直接在Trac数据库上运行, 来设置自定义字段的初始值. 所有没有自定义字段'request_source'值的传票插入缺省值'None':

{{{
#!sql
INSERT INTO ticket_custom
   (ticket, name, value)
   SELECT 
      id AS ticket,
      'request_source' AS name,
      'None' AS value
   FROM ticket 
   WHERE id NOT IN (
      SELECT ticket FROM ticket_custom
   );
}}}

如果你在不同时间点增加了多个自定义字段, 你应该通过在查询中增加此自定义字段名, 以{{{ticket}}}表的子查询中更具体指定:

{{{
#!sql
INSERT INTO ticket_custom
   (ticket, name, value)
   SELECT 
      id AS ticket,
      'request_source' AS name,
      'None' AS value
   FROM ticket 
   WHERE id NOT IN (
      SELECT ticket FROM ticket_custom WHERE name = 'request_source'
   );
}}}

----
原文版本: TracTicketsCustomFields[[BR]]
相关信息: [ZhTracTickets Trac传票], [ZhTracIni Trac配置][[BR]]
See also: TracTickets, TracIni