CustomActionHandler.md

CustomActionHandler

When respond to an action using database method On Mobile App Action, you could provide some data to the iOS app with the result($0) object

You could for instance display a message using statusText

$0:=New object("success"; True; "statusText"; "My information message to display")

$0:=New object("success"; False; "statusText"; "My warning/error message to display")

But if you want to do more and the SDK do not provide it functionnality? (18R5, maybe 18.3)

For that you must provide a swift code, the action handler, which implement the protocol ActionResultHandler.

There is two way to do it, implement in AppDelegate or using an injected ApplicationService

Simple example

import QMobileAPI
import QMobileUI
import SwiftyJSON

extension AppDelegate: ActionResultHandler {
   func handle(result: ActionResult, for action: Action, from: ActionUI, in context: ActionContext) -> Bool {
        let json = result.json
        if json["doSomething"].boolValue {
            // if response containts "doSomething": true 
            // your code here
            return true // yes I handle the action
        }
        return false // no I do not care about the action
    }
}

in db method

$0:=New object("success";True;"doSomething";True)

Full example

To make polling on url and display a message when finishing

iOS side

import SwiftyJSON
import Alamofire
import SwiftMessages

import QMobileAPI
import QMobileUI

extension AppDelegate: ActionResultHandler {

    fileprivate func doNetworkRequest(_ urlString: String, _ step: TimeInterval) {
        /*data request */_ = AF.request(urlString).responseJSON { response in
            guard let data = response.data, let json = try? JSON(data: data) else {
                logger.warning("Failed to decode JSON data from \(urlString)")
                return
            }
            let state = json["state"].stringValue
            switch state {
            case "InProgress", "Scheduled":
                let checkedStep = step <= 0 ? 60: step // default 60s if not defined
                DispatchQueue.userInitiated.after(checkedStep) { [unowned self] in
                    self.doNetworkRequest(urlString, step)
                }
            case "Succeeded", "Failed", "Cancelled":
                logger.debug("Polling \(urlString) end with state \(state)")
            default:
                logger.debug("Unknown state \(state) for polling result")
            }
            if let message = json["statusText"].string {
                if json["success"].boolValue {
                    SwiftMessages.info(message)
                } else {
                    SwiftMessages.warning(message)
                }
            }
        }
    }

    func handle(result: ActionResult, for action: Action, from: ActionUI, in context: ActionContext) -> Bool {
        let pollingParameters = result.json["polling"]
        if let urlString = pollingParameters["url"].string {
            doNetworkRequest(urlString, pollingParameters["step"].doubleValue)
            return true
        }
        return false
    }

}

On db method

// ... some code to launch task and provide a task id 

$0:=New object("success";True;"polling";New object("url"; "http://myserver/4DAction/checkTaskFinish?id=XXX"))

Endpoint

for instance using 4d action

 // get variables to get task id
 ARRAY TEXT($anames;0)
 ARRAY TEXT($avalues;0)
 WEB GET VARIABLES($anames;$avalues)
 // TODO code to find in array the "id" var
 $taskId:= ...
 
 // code to find task information, stask etc
 C_OBJECT($result)
 $result:=...


// then send result
WEB SEND TEXT(JSON Stringify($result))