Offline functionality should describe what a person can actually do without a dependable connection. Reading an earlier copy of a reference page, saving a draft and confirming a live booking are different tasks. They need different rules about freshness, storage and server receipt.
A progressive web app uses web technologies and can offer app-like capabilities, including installation or offline operation where supported. Those capabilities depend on the implementation, browser and platform. Define the required behaviour before choosing an application format.
Separate offline reading from offline changes
List the tasks that must remain available during a connection loss. Some can use cached reference information, while others require a current server decision. A technician may read an earlier instruction sheet offline, but live stock allocation may need a connected check.
Explain freshness to the user. Show the relevant update time or offline state where it affects a decision. An older cached page should not quietly appear to be the latest approved information if that distinction matters to the work.
Define local and server states
A record saved on a device has not necessarily reached the server. Distinguish a local draft, a queued change, a confirmed submission and a failed attempt. The language shown to the user should reflect the state actually established.
Decide what happens if a person closes the application, signs out or loses the device before synchronisation. Explain the limits of local retention and recovery. Local browser storage can support offline work, but its persistence and capacity depend on platform behaviour and configuration.
Plan caching and updates
A service worker can support cached resources and request handling in a web application. Specify which material is cached, when it is refreshed and how a new application version becomes active. Test an upgrade with existing cached data, rather than checking only a clean installation.
Keep sensitive information and permissions in the design review. A cached copy may remain after access to the original source changes. Establish how sign-out, account removal and device use affect locally retained information, with limits appropriate to the task.
Make synchronisation deliberate
Identify the operation, its stable reference and the acknowledgement that confirms server receipt. Use an appropriate duplicate-handling strategy when a queued submission is retried. A connection recovering halfway through a request can leave the application uncertain about whether the action occurred.
Define how conflicts are resolved when another person changes the same record. The newest local timestamp is not automatically the correct business outcome. Some operations need staff review, while others can use a documented authoritative-state rule.
Check background delivery support
Background synchronisation can defer work until a connection becomes available in supported environments. It should not be assumed to operate identically on every target device. Check secure-context requirements, browser support and the conditions under which queued work actually runs.
Provide a visible retry or recovery path where background execution is unavailable or interrupted. A user should be able to identify unconfirmed work and understand what to do next. Do not promise delivery merely because the application has placed an item in a local queue.
Design notifications around useful events
A notification should tell the recipient something relevant and offer an appropriate action. Distinguish reminders, urgent changes and routine status information. Where supported, categories and preferences can help users control those different types.
Request notification permission when its purpose is understandable. Provide a workable experience if permission is denied and avoid exposing sensitive content on a lock screen. Delivery and interaction can vary with operating-system settings, browser behaviour and connectivity.
Test the actual supported devices
- Open the application after the connection is lost.
- Read cached information and check its freshness indication.
- Save and reopen an unconfirmed local entry.
- Reconnect during and after a submission.
- Exercise duplicate and conflicting updates.
- Test denied permissions and interrupted background work.
- Check upgrade, sign-out and local-data removal behaviour.
Record the devices, browsers and conditions covered by the checks. A successful demonstration on one workstation does not establish support for every mobile platform. Include practical instructions for staff who encounter a failure away from the office.
Connect offline design to the business brief
State which tasks are essential, what information can be stale and which actions require a live decision. Our software requirements guide helps turn these decisions into acceptance criteria. Giraffe Digital's digital strategy service can compare the application options against the actual working environment and support needs.
