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Add network verification

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The app doesn't try to get or update the data if the phone is not
online.
This commit is contained in:
dario-cfpt
2020-03-10 10:41:46 +01:00
parent 5336ae83d8
commit bf22d8afc2
4 changed files with 75 additions and 40 deletions
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102
mobile/www/js/database.js
View File

@ -6,45 +6,58 @@ Description : Communicates with the server to ensure that the data is up to date
const BASE_URL = "http://localhost/";
let feData = JSON.parse(localStorage.getItem("feData"));
if (feData != null) {
let body = new FormData();
body.append('version', feData.version);
function isOnline() {
const networkState = (navigator.connection) ? navigator.connection.type : null;
fetch(BASE_URL + "update", {
method: "POST",
body: body,
})
.then(res => {
if (res.ok) {
return res.json();
} else {
console.log(res);
}
})
.then(data => {
updateData(data);
})
.catch(err => {
console.log(err);
});
} else {
// Import the data if none was found
fetch(BASE_URL + "all")
.then(res => {
if (res.ok) {
return res.json();
} else {
console.log(res);
}
})
.then(data => {
updateData(data);
})
.catch(err => {
console.log(err);
});
if (networkState != null && networkState != "none") {
return true;
}
return false;
}
// Get the data from the server or update the data in the localstorage if needed
function getOrUpdateData() {
if (feData != null) {
let body = new FormData();
body.append('version', feData.version);
fetch(BASE_URL + "update", {
method: "POST",
body: body,
})
.then(res => {
if (res.ok) {
return res.json();
} else {
console.log(res);
}
})
.then(data => {
updateData(data);
})
.catch(err => {
console.log(err);
});
} else {
// Import the data if none was found
fetch(BASE_URL + "all")
.then(res => {
if (res.ok) {
return res.json();
} else {
console.log(res);
}
})
.then(data => {
updateData(data);
})
.catch(err => {
console.log(err);
});
}
}
// Update the data in the localstorage
function updateData(data) {
// If the data received from the server are not empty then we can save them in the local storage
if (data != null && Object.keys(data).length > 0) {
@ -54,4 +67,19 @@ function updateData(data) {
// End of the update process, we can now display the data
displayCharacters();
}
}
// Doesn't try to get or update the data if the user is not connected to the internet
if (isOnline()) {
getOrUpdateData();
} else {
// If the user is not connected to internet but the data are already present in the app, then we display them
if (feData != null) {
displayCharacters();
} else {
alert("Please connect to the internet to download the data");
}
// Create an event to get/update the data when the user goes online
document.addEventListener("online", getOrUpdateData, false);
}