Detecting if an input has been modified

🚀 Support (Q&A)
1

Hi! I am wondering if there is an easy way to detect whether the user has modified the value a NumberField. Thanks!

2

Hi,

Welkom back to the community forum.

In the top right corner, you can see a full history of all saved changes made to an entity:
afbeelding

You can check you unsaved changes using when you press ‘Opslaan/save button’:
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and check the changes:
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This shows all changes you have currently made to the entity (before saving them).

Hope this answers your question.

3

Hi! thanks for the reply!

Sorry my question wasn’t very clear. What I meant was if it is possible to detect it using code, something like:

If NumberField_value_changed = True:
do something

4

Hi Yang,

You could make use of an api call to the current entity to get the last saved params and compare them with the current incoming ones:

from viktor.api_v1 import API

class Controller(ViktorController):
    ...

    def controller_method(self, params, entity_id, **kwargs):
        current_value = params.number
        saved_value = API().get_entity(entity_id).last_saved_params.number
        if current_value != saved_value:
            # do something
5

hi @Yang , could you explain what you would like to achieve with this?

6

Thank you! I’ll try this out!

7

Hmm it is a bit hard to explain… my app allows the user to go back and forth between different steps, and change their inputs to iteratively find the best result.

So this a function that I wrote:

def alignment(self) -> GeoPolyline:
    if self.params.elevation.geoline is not None:
        return self.params.elevation.geoline
    else:
        return convert_linestring_to_geo_polyline(self.alignment_line)

It is possible that the user created a geoline, but later changes their mind and want to use the alignment_line instead. Now the geoline is always not None. So I want to find a way to reset it back to None.

8

Maybe you can use a SetParamsButton to clear the field which is conditionally visible if the other fields is set. In pseudo code (no guarantees this works :stuck_out_tongue:).

Would this suit your usecase?

# in parametrization
step1.geoline = GeoLine('My geoline')
step2.reset_geoline = SetParamsButton('Reset geoline', 'clear_geoline', visible=IsNotNone(Lookup('step1.geoline')))

# in controller:
def clear_geoline(self, params, **kwargs):
    return SetParamsResult({'step1': {'geoline': None}} )
9

thanks! this might work, I’ll try it out :slight_smile: