SwiftDetailer

A multi-platform SwiftUI component for editing fielded data.

Available as an open source library to be incorporated in SwiftUI apps.

SwiftDetailer is part of the OpenAlloc family of open source Swift software tools.

macOS	iOS

• Convenient editing (and viewing) of fielded data in your app
• Presently targeting macOS v11+ and iOS v14+**
• Supporting both value and reference semantics (including Core Data, which uses the latter)
• Can be used with various collection container types, such as List, Table, LazyVStack, etc.*
• .editDetailer View modifier, to support (bound, read/write) view
• .viewDetailer View modifier, to support (unbound, read-only) view
• Option to add new item
• Option to delete item
• Option to validate at field-level, with indicators
• Option to validate at record-level, with alert view
• Optional DetailerMenu package available, for convenient invocation
• Minimal use of View type erasure (i.e., use of AnyView)
• No external dependencies!

* And also the companion Tabler component (by the same author)

** Other platforms like macCatalyst, iPad on Mac, watchOS, tvOS, etc. are poorly supported, if at all. Please contribute to improve support!

An example, showing the basic use of Detailer. As a baseline, start with a display of rows of data in a List:

import SwiftUI

struct Fruit: Identifiable {
    var id: String
    var name: String
    var weight: Double
    var color: Color
}

struct ContentView: View {

    @State private var fruits: [Fruit] = [
        Fruit(id: "🍌", name: "Banana", weight: 118, color: .brown),
        Fruit(id: "🍓", name: "Strawberry", weight: 12, color: .red),
        Fruit(id: "🍊", name: "Orange", weight: 190, color: .orange),
        Fruit(id: "🥝", name: "Kiwi", weight: 75, color: .green),
        Fruit(id: "🍇", name: "Grape", weight: 7, color: .purple),
        Fruit(id: "🫐", name: "Blueberry", weight: 2, color: .blue),
    ]

    var body: some View {
        List(fruits) { fruit in
            HStack {
                Text(fruit.id)
                Text(fruit.name).foregroundColor(fruit.color)
                Spacer()
                Text(String(format: "%.0f g", fruit.weight))
            }
        }
    }
}

Then, to add basic support for a detail page, targeting both macOS and iOS, you'll need to:

• A. Import the SwiftDetailer and SwiftDetailerMenu packages.
• B. Add state property for element to edit, and a typealias for cleaner code.
• C. Give each row a menu (context for macOS; swipe for iOS).
• D. Add a call to editDetailer, available as a modifier.
• E. Include a Form containing the fields to edit, and ...
• F. Add an action handler to save a modified Fruit element.

These are shown (and annotated) in the modified code below:

import SwiftUI
import Detailer         // A
import DetailerMenu

struct Fruit: Identifiable {
    var id: String
    var name: String
    var weight: Double
    var color: Color
}

struct ContentView: View {

    @State private var fruits: [Fruit] = [
        Fruit(id: "🍌", name: "Banana", weight: 118, color: .brown),
        Fruit(id: "🍓", name: "Strawberry", weight: 12, color: .red),
        Fruit(id: "🍊", name: "Orange", weight: 190, color: .orange),
        Fruit(id: "🥝", name: "Kiwi", weight: 75, color: .green),
        Fruit(id: "🍇", name: "Grape", weight: 7, color: .purple),
        Fruit(id: "🫐", name: "Blueberry", weight: 2, color: .blue),
    ]
    
    @State private var toEdit: Fruit? = nil // B

    typealias Context = DetailerContext<Fruit>

    var body: some View {
        List(fruits) { fruit in
            HStack {
                Text(fruit.id)
                Text(fruit.name).foregroundColor(fruit.color)
                Spacer()
                Text(String(format: "%.0f g", fruit.weight))
            }
            .modifier(menu(fruit)) // C
        }
        .editDetailer(.init(onSave: saveAction),
                      toEdit: $toEdit,
                      originalID: toEdit?.id,
                      detailContent: editDetail) // D
    }
    
    // E
    private func editDetail(ctx: Context, fruit: Binding<Fruit>) -> some View {
        Form {
            TextField("ID", text: fruit.id)
            TextField("Name", text: fruit.name)
            TextField("Weight", value: fruit.weight, formatter: NumberFormatter())
            ColorPicker("Color", selection: fruit.color)
        }
    }
    
    // F
    private func saveAction(ctx: Context, fruit: Fruit) {
        if let n = fruits.firstIndex(where: { $0.id == fruit.id }) {
            fruits[n] = fruit
        }
    }
    
    // C
#if os(macOS)
    private func menu(_ fruit: Fruit) -> EditDetailerContextMenu<Fruit> {
        EditDetailerContextMenu(fruit) { toEdit = $0 }
    }
#elseif os(iOS)
    private func menu(_ fruit: Fruit) -> EditDetailerSwipeMenu<Fruit> {
        EditDetailerSwipeMenu(fruit) { toEdit = $0 }
    }
#endif
}

On macOS, ctrl-click (or right-click) on a row to invoke the context menu. On iOS, swipe the row to invoke the menu.

For a full implementation, with ability to add new records, see the DetailerDemo project (link below). It extends the example with operations to add new records, delete records, and validate input.

It shows Detailer used with LazyVGrid and Table containers.

You can invoke Detailer by various methods. One way is via context or swipe menus. For optional menu support see SwiftDetailerMenu.

The use of context menus for macOS and iOS:

macOS	iOS

And swipe menu for iOS:

iOS

You can optionally validate data using Detailer. Two approaches are available: field and record level.

Field and record level validation can be used individually or in concert.

This is a lightweight form of validation where individual fields get a closure to test their validity. As they are executed with each change, they should NOT run expensive operations, like hitting a remote server.

Field-level validation is implemented as modifiers in the detail form, as in this example of three(3) validators used in the demo app:

private func editDetail(ctx: DetailerContext<Fruit>, fruit: Binding<Fruit>) -> some View {
    Form {
        TextField("ID", text: fruit.id)
            .validate(ctx, fruit, \.id) { $0.count > 0 }
        TextField("Name", text: fruit.name)
            .validate(ctx, fruit, \.name) { $0.count > 0 }
        TextField("Weight", value: fruit.weight, formatter: NumberFormatter())
            .validate(ctx, fruit, \.weight) { $0 > 0 }
        ColorPicker("Color", selection: fruit.color)
    }
}

The first two are testing string length. The third is testing the numerical value.

By default, invalid fields will be suffixed with a warning icon, currently an "exclamationmark.triangle", as displayed in the images above. This image is configurable.

All field-level validations must return true for the Save button to be enabled.

TIP: for consistent margin spacing in layout, you can create a validation that always succeeds: .validate(...) { _ in true }.

This can be a heavyweight form of validation executed when the user presses the Save button.

It's a parameter of the DetailerConfig initialization, specifically onValidate: (Context, Element) -> [String].

In your action handler, test the record and, if okay, return [], an empty string array. Populate the array with messages if invalid. They will be presented to the user in an alert.

If this validation is used, the user will not be able to save changes until it returns [].

Defaults can vary by platform. See the DetailerConfigDefaults code for specifics.

The can handlers are typically used to enable or disable controls, such as menu items. They are constrained by the definition of their on counterparts.

The on handlers, when defined, will enable the associated operation.

• minWidth: CGFloat - minimum sheet width; default varies by platform
• canEdit: (Element) -> Bool - per-element modification enabling, if onSave defined; defaults to { _ in true }
• canDelete: (Element) -> Bool - per-element deletion enabling, if onDelete defined; defaults to { _ in true }
• onDelete: ((Element) -> Void)? - handler for deletion; defaults to nil
• onValidate: (Context, Element) -> [String] - handler for heavyweight validation; defaults to { _, _ in [] }
• onSave: ((Context, Element) -> Void)? - handler for user save; defaults to nil
• onCancel: (Context, Element) -> Void - handler for user cancel; defaults to { _, _ in }
• titler: ((Element) -> String)? - handler for title generation; defaults to nil
• validateIndicator: (Bool) -> AnyView - defaults to "exclamationmark.triangle" image, with additional attributes

• SwiftDetailerMenu - optional menu support for SwiftDetailer
• DetailerDemo - the demonstration app for this library, using a value data source
• TablerCoreDemo - the demonstration app for this library, using a Core Data source

Swift open-source libraries (by the same author):

• SwiftTabler - multi-platform SwiftUI component for tabular data
• SwiftSideways - multi-platform SwiftUI component for the horizontal scrolling of tabular data in compact areas
• AllocData - standardized data formats for investing-focused apps and tools
• FINporter - library and command-line tool to transform various specialized finance-related formats to the standardized schema of AllocData
• SwiftCompactor - formatters for the concise display of Numbers, Currency, and Time Intervals
• SwiftModifiedDietz - A tool for calculating portfolio performance using the Modified Dietz method
• SwiftNiceScale - generate 'nice' numbers for label ticks over a range, such as for y-axis on a chart
• SwiftRegressor - a linear regression tool that’s flexible and easy to use
• SwiftSeriesResampler - transform a series of coordinate values into a new series with uniform intervals
• SwiftSimpleTree - a nested data structure that’s flexible and easy to use

And commercial apps using this library (by the same author):

• FlowAllocator - portfolio rebalancing tool for macOS
• FlowWorth - a new portfolio performance and valuation tracking tool for macOS

Copyright 2022 FlowAllocator LLC

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Contributions are welcome. You are encouraged to submit pull requests to fix bugs, improve documentation, or offer new features.

The pull request need not be a production-ready feature or fix. It can be a draft of proposed changes, or simply a test to show that expected behavior is buggy. Discussion on the pull request can proceed from there.