Creating traditional symbology with visual specifications (Defense Mapping)

You are not required to use representation symbology. You can assign symbology to features using specification rules using visual specifications by doing the following:

• Creating a calculated fields specification for the symbology
• Creating a calculated fields specification rule
• Matching the calculated field to symbols in a style to apply the symbology

The Match to symbols in a style symbology option requires you to identify a value field and a style set. The value field is the attribute field that contains the name of the symbol to be used for the feature. The style is the style set that contains the symbols identified in the value field. The exact name of the Symbol must be populated in the value field attribute.

You need the following before you start:

• A style with the symbols that you will be using
• The name of the symbols that you will be using
• An understanding of the specifications for feature symbology (what attribute values will dictate the symbol each feature will receive)

Creating the symbology specification

The first part of using visual specifications for traditional symbology is creating the specification.

Etapes :

1. Start ArcMap.
2. On the main menu, click Customize > Toolbars > Production Symbology.
3. Click the Visual Specifications button on the Production Symbology toolbar.

   The Visual Specifications dialog box appears.

4. Click the Visual Specifications Table Location drop-down arrow and choose the location you want to use for your visual specifications table.

   You can choose the product library, if one has been set, or a different location by choosing Browse.

   The Select Visual Specifications Table Location dialog box appears.

5. Navigate to the geodatabase that contains the visual specifications table you want to use.
6. Click Select.

   The Visual Specifications dialog box appears.

7. Click Options > New Specification.

   The New Visual Specification dialog box appears.

8. Type a name for the specification in the Name text box.
9. Type a description for the specification in the Description text box.
10. Click OK.

    The Visual Specifications dialog box appears.

11. Check the Display Calculated Representations and Calculated Fields tabs check box.
12. Click OK.

Creating the calculated fields in the specification

The first part of using visual specifications for traditional symbology is building the specifications rules that identify the attribute combinations that define the symbology of the features.

Etapes :

1. Right-click the layer for which you want to define the calculated fields and click Properties.

   The Layer Properties dialog box appears.

2. Click the Calculated Fields tab.

3. Click the Specification drop-down arrow and choose the specification you just created.
4. Click Options > New Rule.

   A new row appears in the rule table.

5. Double-click the Rule Description field.

   The field becomes editable.

6. Type a name for the rule in the Rule Description text box.
7. Click the ellipsis (...) in the Field Name field.

   The Field Properties dialog box appears.

   This will create a new field that will hold the name of the symbol that you will apply to the feature.

8. Click Add to create a new field.

   The New Field Name dialog box appears.

9. Type a name in the text box.

   For example: VST_Symbology.

10. Click OK.

    The Field Properties dialog box appears.

11. Check the Edit Properties check box.

    The following items become available:

    • Alias
    • Type
    • Length
      Remarque :

      The Length text box only appears if you choose Text in the Type drop-down list.

12. Type an alias name for the field in the Alias text box.
13. Leave the Type drop-down option as Text.
14. Type a length in the Length text box.
15. Click OK.

    The Layer Properties dialog box appears.

16. Click the SQL Statement drop-down arrow and choose Edit SQL statement.

    The Query Builder dialog box appears.

17. Define a query that includes the fields with values you want to use.

    This will identify the features to symbolize with the first rule.

    For example, to symbolize all the Major Roads with two or more lanes, your SQL Statement may look like: Subtype= 1-Major Road AND NumLanes > 2.

18. Click OK.

    The Calculated Fields tab appears.

19. Click the Expression drop-down arrow and click Edit Expression.

    The Expression Parser dialog box appears.

20. Create the expression that contains the name of the symbol to apply to this rule.

    If the features specified above are symbolized using the Freeway symbol contained in the ESRI style set, the expression would look like Generate = Freeway.

21. Click Verify to make sure the expression is valid.
22. Click OK.

    The Calculated Fields tab appears.

23. Repeat steps 4–23 to define the rest of the specification rules.
24. When you are finished defining the rules, click OK to calculate the new field with the appropriate symbology values.
25. To ensure that the feature class is updated with the rule information, verify that the Update Feature Class(es) check box is checked.
26. Click OK.

Matching the symbol name in calculated field to a style

You now have a field in your attribute table that identifies the name of the symbol that should be applied to each of your features. Use the Symbology tab to match the symbol name to a style.

Etapes :

1. Right-click the layer you want to symbolize and click Properties.

   The Layer Properties dialog box appears.

2. Click the Symbology tab.
3. Choose the Match to symbols in a style option under Categories in the left-hand renderer list.
4. Click the Value Field drop-down arrow and choose the field you created above.

   For example: VST_Symbology

5. For Match to symbols in Style, click Browse and navigate to the location of the style that you are using.

   For example: C:\Program Files\ArcGIS\Styles\ESRI.style

6. Click the style you want to apply and click Open.
7. Click Match Symbols and click Apply to use the new symbology.
   Astuce:

   You can use the all other values option to identify a feature that is not defined by the specification rules you created earlier.

If you completed the three parts to the process of using visual specifications for traditional symbology, your features should be symbolized to the specifications you set. In the first part, the specification was created. In the second part, the rules in the specification were created, and the output was a calculated field containing the name of the symbol to use for each feature. In the final part, the calculated field was used in the Match symbol to a style symbology option to apply the symbology to the features.