Link value component

[SepidehAlassi]

to do:
display:

• show the target resource label in a read-only drop-down menu

edit:

• search for all possible resources with given three letters of the label

• list the resource labels of all possible target resources in a drop-down menu

• read the user's choice and assign to the target of the link value

test

• write tests for edit and display

closes #14

[tobiasschweizer]

Thanks for this PR, I will try to review it tomorrow.

[tobiasschweizer]

please see my proposal #47

[tobiasschweizer]

Shall I take another look?

[SepidehAlassi]

Shall I take another look?

if you wish so

[tobiasschweizer]

I think a custom validator function is needed because all modes but update cannot check if the value is actually an instance of ReadResource. I guess you could define something like the following and just include it in the customValidators:

export function resourceValidator(control: AbstractControl) {
    const invalid = !(control.value instanceof ReadResource);
    return invalid ? {'invalidType': {value: control.value}} : null;
}

[tobiasschweizer]

the use case is here is more complex because the value of the FormControl is a string / label as long as the user types and an instance of ReadResource once the user selects from the list.

[SepidehAlassi]

the use case is here is more complex because the value of the FormControl is a string / label as long as the user types and an instance of ReadResource once the user selects from the list.

If I understand what you suggest correctly, you mean there should be a validator to check that a chosen option is an instance of ReadResource. However, in "update", "create", and "search" modes, the dropdown menu shows the options for the user to choose from. These options are always instances of ReadResource. The user does not have any other choice than choosing one item from the menu. Hence, an option selected by the user is always an instance of ReadResource. That would mean that such a double validation would not actually be necessary.

[tobiasschweizer]

However, in "update", "create", and "search" modes, the dropdown menu shows the options for the user to choose from. These options are always instances of ReadResource. The user does not have any other choice than choosing one item from the menu. Hence, an option selected by the user is always an instance of ReadResource. That would mean that such a double validation would not actually be necessary.

Yes, but as long as the user types, the FormControl's value is just a string (the label). So this is to make sure that the user selected an option from the list.

[SepidehAlassi]

the "save" button is inactive unless an option is chosen from the dropdown menu.

[tobiasschweizer]

no, not yet. But you test it by directly adding the link value component to app.component.html. I think @mdelez will wok on a create component soon.

[tobiasschweizer]

or you can just try it out in your spec

[SepidehAlassi]

I am trying out in spec for a while now. It would have been nice to have the component.

[tobiasschweizer]

yes! Now we can make it a user story :-)

[mdelez]

@SepidehAlassi I can start to work on the create component tomorrow

[SepidehAlassi]

@tobiasschweizer I have added the missing validator and tests for creation mode in case user enters a string instead of choosing an item from the dropdown menu.

[SepidehAlassi]

@tobiasschweizer I think this PR can really be merged, oder?

[tobiasschweizer]

@tobiasschweizer I think this PR can really be merged, oder?

I think you are almost done, please see my comments.

[SepidehAlassi]

@tobiasschweizer Can I merge this now?

[tobiasschweizer]

I think the idea of clearing the selection is good, what I meant is just this.resources = []

[tobiasschweizer]

looks good, thanks

I have just one last comment: #27 (review)

[SepidehAlassi]

@tobiasschweizer I have already initialized it here to an empty array

[tobiasschweizer]

I understood that your idea of clearing selection empties the list when the user types and the string is still too short. I think this idea is good.

[tobiasschweizer]

I think this is important when user selects a resource and then wants to change it again. Then the selection has to change to.

[tobiasschweizer]

because I think otherwise you still get the old selection when the label string is shorter than 3 chars

[tobiasschweizer]

but maybe I am wrong, I will leave this to you. Please proceed as you want.

[SepidehAlassi]

looks good, thanks

I have just one last comment: #27 (review)

see my reply above