mapping-from-excel

name	mapping-from-excel
description	Description on how to create a flogo file that follows an excel mapping
user-invocable	true

Key Facts (verified)

• Mapper activity type: act_general_mapper
• Logger activity type: act_general_log
• Timer trigger type: tr_timer
• String concatenation in Flogo expressions: use string.concat(a, b) — NOT the & operator
• Mapper output path: $activity[<activity_name>].output.<field> — NOT .output.output.<field>
• All set-attribute calls for schemas and mappings need the --force flag (attributes don't pre-exist)
• create-trigger-handler inline syntax: fda cth <flow-name> <trigger-id>
• create-activity inline syntax: fda ca <flow-name> <activity-name> <activity-type>

---

Step 1: Read the Excel file

Read the Excel file using Python (openpyxl). Extract:

• Column 1 → Input field names
• Column 2 → Output field names
• Column 3 → Mapping rules (source expression per output field)

python3 -c "
import openpyxl
wb = openpyxl.load_workbook('<excel-file>')
ws = wb.active
for row in ws.iter_rows(values_only=True):
    print(row)
"

---

Step 2: Create project, flow, activities, trigger

Run all commands from your Flogo apps directory (e.g. ./Flogo_Apps/).

# Create flow (creates project file if it doesn't exist)
fda create-flow mapping_from_excel -f <AppName>.flogo

# Add activities (automatically linked in sequence)
fda ca mapping_from_excel mapper1 act_general_mapper -f <AppName>.flogo
fda ca mapping_from_excel mapper2 act_general_mapper -f <AppName>.flogo
fda ca mapping_from_excel logger  act_general_log    -f <AppName>.flogo

# Add timer trigger + handler
fda create-trigger timerTrigger tr_timer -f <AppName>.flogo
fda cth mapping_from_excel timerTrigger -f <AppName>.flogo

# Format flow
fda format-flow mapping_from_excel -f <AppName>.flogo

---

Step 3: Create JSON schemas

Create one schema for input fields and one for output fields.

fda cs InputSchema  '{"$schema":"http://json-schema.org/draft-04/schema#","type":"object","properties":{"<field1>":{"type":"string"},...}}' -f <AppName>.flogo
fda cs OutputSchema '{"$schema":"http://json-schema.org/draft-04/schema#","type":"object","properties":{"<field1>":{"type":"string"},...}}' -f <AppName>.flogo

---

Step 4 & 5: Assign schemas to mappers

fda sa activity mapping_from_excel.mapper1.schemas.input.input "schema://InputSchema"  -f <AppName>.flogo --force
fda sa activity mapping_from_excel.mapper2.schemas.input.input "schema://OutputSchema" -f <AppName>.flogo --force

---

Step 6: Set example input values in mapper1

Set one field at a time:

fda sa activity mapping_from_excel.mapper1.input.input.mapping.<FieldName> "<example-value>" -f <AppName>.flogo --force

Repeat for every input field.

---

Step 7: Set output mappings in mapper2

Map each output field from mapper1's output. Use --force on every call.

• Simple field mapping:

  fda sa activity "mapping_from_excel.mapper2.input.input.mapping.<OutputField>" \
    '=$activity[mapper1].output.<InputField>' -f <AppName>.flogo --force
  

• Concatenation of two fields (use string.concat, NOT &):

  fda sa activity "mapping_from_excel.mapper2.input.input.mapping.<OutputField>" \
    '=string.concat($activity[mapper1].output.<Field1>, " ", $activity[mapper1].output.<Field2>)' \
    -f <AppName>.flogo --force
  

---

Step 8: Set logger message to mapper2 output

fda sa activity "mapping_from_excel.logger.input.message" \
  '=coerce.toString($activity[mapper2].output)' -f <AppName>.flogo --force

---

Step 9: Build, run, and verify

# Build (use the flogobuild context configured for your Flogo version, e.g. flogo-2.26.0-1789)
mkdir -p ./bin
flogobuild build-exe -f <AppName>.flogo -c <YOUR_FLOGO_CONTEXT> -o ./bin

# Run for 5 seconds and read log output
chmod +x ./bin/<AppName>
timeout 5 ./bin/<AppName> 2>&1 || true

The logger should print a JSON object with the mapped output fields.