This transformer can be used to ensure that the representation of null, empty, and missing attributes on the feature matches the representation expected by the output format, or downstream transformer.
In addition, some users might use a special value to represent null, missing, or empty. This transformer will allow you to map to and from that special value.
Parameters
Attributes To Map
Map
Whether to mapAll AttributesorSelected Attributes.All Attributeswill operate on all attributes present on the feature, including format attributes. Please note thatAll Attributeswill not operate on missing attributes. To map missing attributes, users must chooseSelected Attributes.
Selected Attributes
Users must explicitly specify attributes to be mapped. Please note that checking ‘Select all’ within the ‘Select Selected Attributes Items’ dialog is not generally the same as choosingAll Attributes为了Map参数。For example, many existing attributes on the feature may not be exposed. In this case,All Attributeswill process these unexposed attributes, whileSelected Attributeswill not be able to.
映射到
If Attribute Value Is
为指定的属性,检查t的值he attribute in the input feature and if it is one of the specified values, take the action specified by the映射到参数。可以匹配的值是：
- Empty- 属性存在，并且有一个空字符串作为它的值。
- Null– The attribute exists and has a value of null.
- 失踪（所选属性只）– The attribute does not exist. This choice does not apply if theMap参数设置为All Attributes. We can only know that an attribute is missing if it has been explicitly specified through theSelected Attributes参数。
Or If Attribute Value Is
If this parameter has a value, this parameter specifies the value to match. If the attribute value matches the specified value, the映射到action will be applied.
Or If Attribute Value Matches Regex
If this parameter has a value, this parameter specifies a regular expression (advanced regular expression (AREs) are supported). If the attribute value matches the specified regular expression, then the映射到action will be applied.
If the parameter is set toYes, Advanced Regular Expressions (AREs) are supported. An ARE is one or more branches, separated by "|", matching anything that matches any of the branches.
If the parameter is set to Yes, the Regex Editor will be available in the parameter menu.
下表列出了特殊字符：
| 特殊字符 | 描述 |
|---|---|
| | | separates "branches" (or choices) |
| * | a sequence of 0 or more matches of what precedes it |
| + | a sequence of 1 or more matches of what precedes it |
| ? | 的东西它之前0或1的匹配序列 |
| . | 匹配任何单个字符 |
| ^ | matches the start of the value |
| $ | matches the end of the value |
| [ ] | 附上一组字符的选择 |
| ( ) | 括一个“子表达式” - 不管每个子表达式匹配放入_matched_parts {}列表属性 |
| a | any character can be listed to be matched |
映射到
This parameter specifies how to map matching attributes. Possible actions are:
- Null– This will cause the attribute to be set to a null value.
- 失踪– The attribute will be deleted.
- 空字符串- 属性值将被设置为一个空字符串（其长度为0）。
- New Value– The attribute will be set to the value specified by theNew Value参数。
New Value
This parameter specifies the value to set an attribute to ifNew Valueis specified as the映射到action.
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click
beside the applicable parameter. For more information, see变压器参数菜单选项.
Transformer Categories
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TagsKeywords: NullAttributeReplacer NullAttributeRemover BulkAttributeMapper