Creating a feature for undo/redo in VueJS involves watching the settings and adding a new element to an array of changes when there is a setting change. Additionally, there is a method for undoing actions when the corresponding button is clicked.
An issue arises when clicking the undo button and reverting the last setting update triggers the watch function again.
To address this problem, how can we prevent adding a new element to the changes array if the settings changed due to the Undo button being clicked?
(function () {
var Admin = {};
Admin.init = function () {
};
var appData = {
settings: {
has_border: true,
leave_reviews: true,
has_questions: true
},
mutations: [],
mutationIndex: null,
undoDisabled: true,
redoDisabled: true
};
var app = new Vue({
el: '#app',
data: appData,
methods: {
undo: function() {
if (this.mutations[this.mutationIndex - 1]) {
let settings = JSON.parse(this.mutations[this.mutationIndex - 1]);
this.settings = settings;
this.mutationIndex = this.mutations.length - 1;
console.log (settings);
}
},
redo: function() {
}
},
computed: {
border_class: {
get: function () {
return this.settings.has_border ? ' rp-pwb' : ''
}
},
undo_class: {
get: function () {
return this.undoDisabled ? ' disabled' : ''
}
},
redo_class: {
get: function () {
return this.redoDisabled ? ' disabled' : ''
}
}
},
watch: {
undoDisabled: function () {
return this.mutations.length;
},
redoDisabled: function () {
return this.mutations.length;
},
settings: {
handler: function () {
let mutation = JSON.stringify(this.settings),
prevMutation = JSON.stringify(this.mutations[this.mutations.length-1]);
if (mutation !== prevMutation) {
this.mutations.push(mutation);
this.mutationIndex = this.mutations.length - 1;
this.undoDisabled = false;
}
},
deep: true
}
}
});
Admin.init();
})();