5. Form Property Types

Forms are defined using <flowable:formProperty> within <extensionElements>.

Custom Type Hints (Value Attribute)

Use <activiti:value id="type" name="..."/> for special rendering:

<!-- Textarea example -->
<activiti:formProperty id="description" name="Description" type="string" required="true">
    <activiti:value id="type" name="textarea"/>
</activiti:formProperty>

<!-- File upload via type hint -->
<activiti:formProperty id="report_doc" name="Report Document" type="string" required="true">
    <activiti:value id="type" name="file"/>
</activiti:formProperty>

File Type Restrictions (Accept Attribute)

You can restrict which file types a file upload field accepts using the accept value attribute. This filters the file picker in the browser and validates the file type on the server when submitted.

If no accept value is provided, all file types are accepted (default behaviour).

Available Categories

Use these category names to allow common groups of file types:

Usage Examples

<!-- Accept only documents (PDF, Word, etc.) -->
<activiti:formProperty id="report_doc" name="Report Document" type="string" required="true">
    <activiti:value id="type" name="file"/>
    <activiti:value id="accept" name="documents"/>
</activiti:formProperty>

<!-- Accept documents and images -->
<activiti:formProperty id="attachment" name="Attachment" type="string">
    <activiti:value id="type" name="file"/>
    <activiti:value id="accept" name="documents,images"/>
</activiti:formProperty>

<!-- Accept only specific extensions -->
<activiti:formProperty id="data_file" name="Data File" type="string" required="true">
    <activiti:value id="type" name="file"/>
    <activiti:value id="accept" name=".xls,.xlsx,.csv"/>
</activiti:formProperty>

<!-- Mix categories with raw extensions -->
<activiti:formProperty id="mixed" name="Mixed File" type="string">
    <activiti:value id="type" name="file"/>
    <activiti:value id="accept" name="documents,.csv"/>
</activiti:formProperty>

Note: If an unrecognized category name is used (e.g. a typo), the BPMN Validation Service will show a warning during upload but will not block deployment.

Dynamic Labels (User-Entered Notes Shown as Text)

Use the label type hint combined with writable="false" to display a process variable as plain informative text instead of a disabled input field. This is ideal for showing notes, instructions, or context written by a previous user in the workflow.

How it works:

1. In one task, the user enters text into a normal form field (stored as a process variable).
2. In a subsequent task, the same variable is rendered as a styled text label using the label type hint.

Difference from writable="false" alone:

• writable="false" renders a greyed-out, disabled input field.
• writable="false" + label type hint renders clean, styled text — visually distinct from form inputs.

<!-- Task 1: Manager writes a note (normal editable textarea) -->
<userTask id="managerReview" name="Manager Review" flowable:assignee="${manager}">
    <extensionElements>
        <activiti:formProperty id="managerNote" name="Note for Employee" type="string">
            <activiti:value id="type" name="textarea"/>
        </activiti:formProperty>
        <activiti:formProperty id="decision" name="Decision" type="enum" required="true">
            <activiti:value id="approve" name="Approve"/>
            <activiti:value id="reject" name="Reject"/>
        </activiti:formProperty>
    </extensionElements>
</userTask>

<!-- Task 2: Employee sees the manager's note as a label (not an input) -->
<userTask id="notifyEmployee" name="View Result" flowable:assignee="${initiator}">
    <extensionElements>
        <activiti:formProperty id="managerNote" name="Manager's Note" type="string" writable="false">
            <activiti:value id="type" name="label"/>
        </activiti:formProperty>
    </extensionElements>
</userTask>

Tip: You can also use the label type hint with a default value (no prior task needed) to show static informative text as a form field label:

<activiti:formProperty id="info" name="Notice" type="string" writable="false" default="All submissions are final and cannot be changed.">
    <activiti:value id="type" name="label"/>
</activiti:formProperty>

Field Permissions & Visibility

You can control how fields appear in the form using standard BPMN attributes:

<!-- Read-Only (Disabled) Field -->
<activiti:formProperty id="originalRequest" name="Original Request" type="string" writable="false"/>

<!-- Hidden Field (e.g., for internal logic) -->
<activiti:formProperty id="internalStatus" name="Status" type="string" readable="false"/>

Task Documentation (Static Labels)

You can add static informational text to any User Task using the standard BPMN <documentation> element. This text is displayed as a highlighted label at the top of the task form, above the form fields.

• The text is static — it is defined in the BPMN XML and appears the same on every instance of the workflow.
• Each task can have its own <documentation>, so different tasks in the same process can show different instructions.
• Long text wraps automatically.
• If no <documentation> is present, nothing is shown.

<!-- Task with static instructions -->
<userTask id="reviewTask" name="Review Request" flowable:assignee="${initiator}">
    <documentation>Please review all attached documents carefully before making your decision.</documentation>
    <extensionElements>
        <activiti:formProperty id="decision" name="Decision" type="enum" required="true">
            <activiti:value id="approve" name="Approve"/>
            <activiti:value id="reject" name="Reject"/>
        </activiti:formProperty>
    </extensionElements>
</userTask>

<!-- Another task with different instructions -->
<userTask id="uploadTask" name="Upload Documents" flowable:assignee="${initiator}">
    <documentation>Upload the signed contract and any supporting documents. Maximum 3 files.</documentation>
    <extensionElements>
        <activiti:formProperty id="file_contract" name="Contract" type="string" required="true">
            <activiti:value id="type" name="file"/>
        </activiti:formProperty>
    </extensionElements>
</userTask>

Note: <documentation> is a standard BPMN 2.0 element, not a Flowable extension. It is placed directly inside the <userTask> element, before <extensionElements>.