145 lines
6.6 KiB
Markdown
145 lines
6.6 KiB
Markdown
# Script Tasks
|
||
Writing scripts refers to the process of creating custom code or scripts to enhance the functionality and automation of a software application or system.
|
||
|
||
In SpiffArena, the scripting language used for writing scripts is Python, a widely used programming language.
|
||
|
||
Python offers a rich array of libraries, frameworks, and tools that facilitate script development, making it a popular choice for implementing custom logic and automation.
|
||
|
||
Let's explore an example of a Script Task in our basics section:
|
||
|
||
1. **Start Event and User Task - "Form"**
|
||
|
||
The process starts with a Start Event, followed by a User Task named "Form".
|
||
|
||
Users fill out the form, and the three values from the form are passed to the subsequent task, which is a Script Task.
|
||
|
||
2. **Script Task to collect data**
|
||
|
||
In the Script Task, we have created a script that collects three variables from the form and calculates a score based on certain conditions.
|
||
|
||
The score is then stored in the "score" variable.
|
||
|
||
Let's delve into how we configured the script tasks:
|
||
|
||
|
||
|
||
**Step 1**: With the script task selected, you will notice the properties tab.
|
||
|
||
**Step 2**: Within the properties tab, there should be a field where you can write or edit a script.
|
||
|
||
You can paste or write your script in this field.
|
||
|
||
Here's the script we added for this example:
|
||
|
||
```python
|
||
if flag_stars.lower().strip() == "twelve":
|
||
num_correct += 1
|
||
elif int(flag_stars) == 12:
|
||
num_correct += 1
|
||
|
||
if "nile" in longest.lower():
|
||
num_correct += 1
|
||
|
||
if "curie" in woman_nobel.lower():
|
||
num_correct += 1
|
||
|
||
score = int(num_correct / 3 * 100)
|
||
```
|
||
|
||
**Step 3**: After adding the script, the next step is to configure unit tests.
|
||
|
||
Within the unit tests section, there are fields to add test inputs and outputs.
|
||
|
||
```json
|
||
// Test Inputs
|
||
{
|
||
"flag_stars": "12",
|
||
"longest_river": "nile",
|
||
"woman_nobel": "curie"
|
||
}
|
||
|
||
// Test Outputs
|
||
{
|
||
"flag_stars": "12",
|
||
"longest": "nile",
|
||
"num_correct": 3,
|
||
"score": 100,
|
||
"woman_nobel": "curie"
|
||
}
|
||
```
|
||
|
||
Now, we have configured our script task with a script and unit tests.
|
||
|
||
3. **Pre Scripts and Post Scripts**
|
||
|
||
After the Script Task, we have a Manual Task with a pre-script and instructions to display the score.
|
||
|
||
|
||
|
||
- **Pre-script** is added as an example.
|
||
|
||
While you can have tasks that are dedicated scripts, it can become a bit noisy, and we want our diagrams to convey a clear sense of the business logic and rules.
|
||
|
||
For this reason, it is also possible to add scripts to all Task types - using Pre and Post Scripts.
|
||
|
||
This manual task contains a pre-script that also calculates PI using Leibniz’s formula.
|
||
|
||
Here is the pre-script:
|
||
|
||
```python
|
||
# Initialize denominator
|
||
k = 1
|
||
|
||
# Initialize sum
|
||
s = 0
|
||
|
||
for i in range(1000000):
|
||
|
||
# even index elements are positive
|
||
if i % 2 == 0:
|
||
s += 4/k
|
||
else:
|
||
|
||
# odd index elements are negative
|
||
s -= 4/k
|
||
|
||
# denominator is odd
|
||
k += 2
|
||
|
||
pi = s
|
||
del(k)
|
||
```
|
||
|
||
- **Post Scripts** are also available on most task types, but they execute AFTER the task is completed.
|
||
|
||
These are great for user forms where you want to modify and clean up the form results before moving on to the next task.
|
||
|
||
## Functions available to script tasks
|
||
|
||
Please see the [implementing files themselves](https://github.com/sartography/spiff-arena/tree/main/spiffworkflow-backend/src/spiffworkflow_backend/scripts) for the details.
|
||
|
||
| Function Name | Description |
|
||
|----------------------------------|----------------------------------------------------------------------------------------------|
|
||
| delete_process_instances_with_criteria | Deletes process instances that match the provided criteria. |
|
||
| get_all_permissions | Gets all permissions currently in the system. |
|
||
| get_current_task_info | Returns information about the current task. |
|
||
| get_current_user | Returns the current user. |
|
||
| get_data_sizes | Returns information about the size of task data. |
|
||
| get_encoded_file_data | Returns the encoded file data. This is a very expensive call. |
|
||
| get_env | Returns the current environment (e.g., testing, staging, production). |
|
||
| get_frontend_url | Returns the URL to the frontend. |
|
||
| get_group_members | Returns the list of usernames of the users in the given group. |
|
||
| get_last_user_completing_task | Returns the last user who completed the given task. |
|
||
| get_localtime | Converts a Datetime object into a Datetime object for a specific timezone. |
|
||
| get_process_initiator_user | Returns the user that initiated the process instance. |
|
||
| get_secret | Returns the value for a previously configured secret. |
|
||
| get_task_data_value | Checks if a given value is in task data and returns its value. If it does not exist or is None, it returns the default value. |
|
||
| get_toplevel_process_info | Returns information about the currently running process. |
|
||
| get_url_for_task_with_bpmn_identifier | Returns the URL to the task show page for a task with the given BPMN identifier. The script task calling this MUST be in the same process as the desired task. |
|
||
| get_user_properties | Gets the user properties for the current user. |
|
||
| markdown_file_download_link | Returns a markdown format string for a file download link. |
|
||
| refresh_permissions | Adds permissions using a dictionary. |
|
||
| set_user_properties | Sets given user properties on the current user. |
|
||
| times_executed_by_user | Returns the number of times the user has started an instance of the current process model. |
|
||
| user_has_started_instance | Returns a boolean indicating if the user has started an instance of the current process model. |
|