Re-using a command

[smithmx]

The MVVM / Single page app requires us to re-use commands. In most cases this will be a command that adds a new instance of something. We should make this easier to do and remove a lot of the coding the front end developer has to do.

1. We want to be able to how the command can be put into a "new" state. Typically, you want a new commandId (rather than reuse the same one!), you want a new Id created for the entity you are adding, you want any constants set on the command (e.g. if adding a new contact to a supplier, you want the supplierId set).
2. We want to reset the values silently, so that validation messages do not appear.

[einari]

One thing I’ve been thinking about is the ability to have value providers - not only for commands but for other things like parameters on queries and such. 

Typically you could have a value provider that points to anything, such as a query string parameter in the browser or a factory that gets called to create the value - typically for unique IDs or similar. 

When we fire off the command, we create a copy of the original one anyways, so my guess is that it is for the values that change and a good way for describing the value source.

— Sent from Mailbox

On Mon, Aug 25, 2014 at 9:35 AM, Michael Smith notifications@github.com wrote:

The MVVM / Single page app requires us to re-use commands. In most cases this will be a command that adds a new instance of something. We should make this easier to do and remove a lot of the coding the front end developer has to do.

1. We want to be able to how the command can be put into a "new" state. Typically, you want a new commandId (rather than reuse the same one!), you want a new Id created for the entity you are adding, you want any constants set on the command (e.g. if adding a new contact to a supplier, you want the supplierId set).

2. We want to reset the values silently, so that validation messages do not appear.

Reply to this email directly or view it on GitHub: https://github.com/dolittle/Bifrost/issues/511

[smithmx]

Yeah, my first thinking was that we have a Init(setup) method where you pass in all the actions you want to be performed when getting a new instance. We first reset everything in the command and then apply the actions provided. I sense you have a more comprehensive approach though... :-)

[einari]

Your senses are right :) I think it could be a less obtrusive one as well, not sure yet..   But the idea is the same. 

Could also be something like

…

myViewModel: Bifrost.views.ViewModel.extend(function(myCommand) {

   myCommand.someProperty.populatedBy(function...)

   myCommand.someProperty.populatedFrom(.. another observable..);

});

Something like that..  Not sure yet.. 

— Sent from Mailbox

On Mon, Aug 25, 2014 at 9:50 AM, Michael Smith notifications@github.com wrote:

Yeah, my first thinking was that we have a Init(setup) method where you pass in all the actions you want to be performed when getting a new instance. We first reset everything in the command and then apply the actions provided. I sense you have a more comprehensive approach though... :-)

Reply to this email directly or view it on GitHub: https://github.com/dolittle/Bifrost/issues/511#issuecomment-53236705