Develop Reference

deep filtering on array of objects

I have data like this one below
let data = [
{
name: 'basic',
to: 'aaa',
subMenus: [
{
name: 'general conc',
to: 'geneal',
},
{
name: 'example view',
to: 'example',
},
{
name: 'fancy',
to: 'bbb',
innerSubMenus: [
{
name: 'adding',
to: 'add',
},
{
name: 'getting',
to: 'get',
},
]
}
]
}
]
I need to filter data based on name (in main, subMenus, and innerSubMenus)
Here is the piece of code
function deepFilter(inputText){
data.filter(items => items.name.toLowerCase().includes(inputText.toLowerCase()))
}
As you can see, the function filters the first prop (name --> basic in this case when inputText = 'basic', doesn't work when inputText = 'general conc') but I want to be able to filter names in subMenus and innerSubMenus as well. Please, guide me on how to do it. Thanks
expected outputs:
deepFilter('basic') -> true // only this part is covered by my implementation
deepFilter('general conc') -> true
deepFilter('adding') -> true
deepFilter('ffff') -> false //since there is not name with value of 'ffff' in data

I think this should work well.
function deepFilter(inputText, datas) {
return datas.filter(data => {
function checkInsideObj(object, inputText) {
for (let value of Object.values(object)) {
if (object.name && object.name.toLowerCase() === inputText.toLowerCase()) {
return true;
}
if (Array.isArray(value)) {
return value.some(item => {
return checkInsideObj(item, inputText)
}
)
}
}
return false;
}
return checkInsideObj(data, inputText)
}
)
}
deepFilter("input", data)

Lodash/JS - Convert _.find statement to _.forEach

I'm having trouble converting the following Lodash statement to something that works in an application that I inherited at work and am trying to fix bugs in. At the moment, we are having issues with only one device on our system returning when two devices have the same name and the following code seems to be the culprit as it would only return the first "true" value in an array:
var group = _.find(groupList, {id: id});
How would I successfully convert this to a statement that iterates over all objects in an array and then returns those objects? I've tried the following options to no avail:
var group = _.filter(groupList, {id: id});
and
var group = _.every(groupList, {id: id});
and
var group = _.forEach(groupList, {id: id})
return {id};
I know I am probably missing something in my syntax. Any help would be much appreciated. Running Lodash v3.7.0
Here's the rest of the code in the directive in case anyone is interested or sees something else I might be missing:
define(['./../_module'], function (directives) {
'use strict';
directives.directive('dmGroupedList', ['$compile', '$state', 'APP_CONSTANTS', function ($compile, $state, APP_CONSTANTS) {
return {
restrict: 'A',
scope: {
items: '=',
groupBy: '=',
actions: '=',
nonameGroupLabel: '='
},
templateUrl: function (elem, attrs) {
return attrs.templateUrl || 'views/shared-templates/grouped-list.html';
},
link: function (scope, element, attrs) {
scope.$watchGroup(['items', 'groupBy', 'nonameGroupLabel'], function () {
scope.groupList = [];
scope.groupedItems = {};
var actions = scope.actions[scope.groupBy];
_.forEach(scope.items, function (item) {
scope.handlers.getGroups(scope.groupList, item, scope.items, scope.groupBy, actions);
});
_.forEach(scope.groupList, function (group) {
var items = scope.groupedItems[group.id];
items = _.sortBy(items, function (item) {
return item.description;
});
scope.groupedItems[group.id] = items;
});
var groupsToSort = _.where(scope.groupList, {unassigned: false});
var unassignedGroups = _.sortBy(_.where(scope.groupList, {unassigned: true}), 'name');
scope.groupList = _.sortBy(groupsToSort, function (group) {
return group.name;
});
//adds unassigned groups to a new array via the javascript "push" method
if (angular.isDefined(unassignedGroups)) {
for (var i = 0; i < unassignedGroups.length; i++) {
scope.groupList.push(unassignedGroups[i]);
}
}
});
scope.handlers = {
getGroups: function (groupList, item, items, groupBy, actions) {
var group = item[groupBy];
if (_.isEmpty(group)) {
scope.handlers.addGroupToList(groupList, APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE, items, groupBy, item, actions, scope);
}
else {
if (angular.isArray(group) || angular.isObject(group)) {
_.forEach(group, function (groupName) {
if (groupName == APP_CONSTANTS.ZERO) {
scope.handlers.addGroupToList(groupList, APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE, items, groupBy, item, actions, scope);
return;
}
scope.handlers.addGroupToList(groupList, groupName, items, groupBy, item, actions, scope);
})
} else {
scope.handlers.addGroupToList(groupList, group, items, groupBy, item, actions, scope);
}
}
},
addGroupToList: function (groupList, groupId, items, groupBy, item, handlers, scope) {
var id = _.camelCase(groupId);
var group = _.find(groupList, {id: id});
//var group = _.forEach(groupList, {id: id})
//return {id};
if (!group) {
var name = '';
var unassigned = false;
var link = null;
if (groupId == APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE || groupId == APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE_PARENT_ID) {
if (groupId == APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE_PARENT_ID) {
name = APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.NONE;
} else {
name = APP_CONSTANTS.DEVICE_NONE_NAME_MAPPING.UNASSIGNED;
}
unassigned = true;
} else {
link = handlers.getGroupLink(groupId);
name = handlers.getGroupName(groupId, items);
}
group = {id: id, name: name, unassigned: unassigned, link: link};
groupList.push(group);
}
scope.groupedItems[group.id] = scope.groupedItems[group.id] || [];
if (angular.isDefined(handlers.processingGroup)) {
handlers.processingGroup(group, groupList, groupId, items, groupBy, item, handlers, scope);
} else {
scope.groupedItems[group.id].push({
description: handlers.getItemDescription(item),
link: handlers.getItemLink(item)
})
}
}
};
}
};
}]);
});

You can just use filter:
var group = groupList.filter((group) => group.id === id);
EDIT: to return only the element, and not an array, when there is only one match, you can do the following:
var checkSingle = (groups) => groups.length === 1 ? groups[0] : groups;
var group = checkSingle(groupList.filter((group) => group.id === id));

You can _(groupList).groupBy('id').get(id):
var groupList = [
{ id: 1, name: 'site' },
{ id: 2, name: 'test' },
{ id: 2, name: 'prod' },
{ id: 3, name: 'dev' },
{ id: 4, name: 'back' },
{ id: 4, name: 'front' },
{ id: 5, name: 'sprint' }
];
console.log(_(groupList).groupBy('id').get(2));
console.log(_(groupList).groupBy('id').get(3));
console.log(_(groupList).groupBy('id').get(4));
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

v2.canGoForward is not a function

I am trying to move the code vm.canGoForward from my controller to a service to hide the implementation details.
BEFORE CODE CHANGE
This worked fine.
View:
<button ng-disabled="!vm.canGoForward()" class="btn btn-primary" name="next" type="button" ng-click="vm.gotoStep(vm.currentStep + 1)">
Controller:
var vm = this;
vm.currentStep = 1;
vm.steps = WizardService.getWizardSteps(vm.formData);
vm.canGoForward = function() {
var res = true,
i,
nextStateIndex = vm.currentStep + 1;
if (nextStateIndex > vm.steps.length) {
return false;
}
for (i = 1; res && i <= nextStateIndex; i++) {
res = (res && vm.steps[i-1].isReady());
}
return !!res;
};
Service
var wizardService = {
getWizardSteps: getWizardSteps
};
return wizardService;
function getWizardSteps(formData) {
var wizardSteps = [
{
step: 1,
name: 'Name',
template: 'views/wizard/step1.html',
isReady: function() { return true; }
},
{
step: 2,
name: 'Email',
template: 'views/wizard/step2.html',
isReady: function() { return formData.firstName && formData.lastName; }
},
{
step: 3,
name: 'Job Category',
template: 'views/wizard/step3.html',
isReady: function() { return formData.email; }
}
];
return wizardSteps;
}
AFTER CODE CHANGE
View
Remains the same
Controller
var vm = this;
vm.currentStep = 1;
vm.steps = WizardService.getWizardSteps(vm.formData);
vm.canGoForward = WizardService.canGoForward(vm.currentStep, vm.steps);
Service
var wizardService = {
getWizardSteps: getWizardSteps,
canGoForward: canGoForward
};
return wizardService;
function getWizardSteps(formData) {
var wizardSteps = [
{
step: 1,
name: 'Name',
template: 'views/wizard/step1.html',
isReady: function() { return true; }
},
{
step: 2,
name: 'Email',
template: 'views/wizard/step2.html',
isReady: function() { return formData.firstName && formData.lastName; }
},
{
step: 3,
name: 'Job Category',
template: 'views/wizard/step3.html',
isReady: function() { return formData.email; }
}
];
return wizardSteps;
}
function canGoForward(currentStep, steps) {
console.log(steps);
var res = true,
i,
nextStateIndex = currentStep + 1;
if (nextStateIndex > steps.length) {
return false;
}
for (i = 1; res && i <= nextStateIndex; i++) {
res = (res && steps[i-1].isReady());
}
return !!res;
}
I now get the following error: TypeError: v2.canGoForward is not a function. How can I resolve it?

In your second version, the following line will actually call WizardService.canGoForward on the spot, not assign it:
vm.canGoForward = WizardService.canGoForward(vm.currentStep, vm.steps);
What gets assigned is the return value of that call, which obviously is not a function, hence the error message when a call is attempted later.
If you want to assign the function, and ensure the arguments get passed when it is called later, then use bind:
vm.canGoForward = WizardService.canGoForward.bind(WizardService, vm.currentStep, vm.steps);

How to create an observable stream of custom objects using RxJS operators

I currently have input which looks as follows
const config = {
'mainA': { sub1: { name: 'test1'}, sub2: { name: 'test2'}},
'mainB': { sub1: { name: 'test3'}, sub2: { name: 'test4'}}
};
I'm trying to write a function (createCustomObservable) which would create an observable using standard RsJS operators as follows
var observable = createCustomObservable(config);
observable.subscribe((x) => console.log(x));
The console output should read as follows
{'mainA': 'test1'} -> {'mainA': 'test2'} -> {'mainB': 'test3'} -> {'mainB': 'test4'}
A series of objects with a single propery
Does anyone have any idea how to realise this using RxJS operators? Any help would be appreciated.

The main problem for what you trying to solve is traverse the object to get all the objects that contains the "name" field, and get their value.
There's no Rx operator to automatically do that, so to achieve this task you can simply use Rx.Observable.create - https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/create.md
const config = {
'mainA': {
sub1: {
name: 'test1'
},
sub2: {
name: 'test2'
}
},
'mainB': {
sub1: {
name: 'test3'
},
sub2: {
name: 'test4'
}
}
};
function traverse(o, func) {
for (var i in o) {
func.apply(this, [i, o[i]]);
if (o[i] !== null && typeof(o[i]) == "object") {
//going on step down in the object tree!!
traverse(o[i], func);
}
}
}
var source = Rx.Observable.create(function(observer) {
traverse(config, function(key, value) {
if (key == "name")
observer.onNext(value);
});
observer.onCompleted();
return function() {
console.log('disposed');
};
});
source.subscribe(function(next) {
console.log(next);
})
Sample: https://jsbin.com/yolufovubi/edit?js,console

we can create a new stream by Observable constructor, You have to manually call next(), error() and complete() functions.
function createCustomObservable(config) {
return new Observable(
observer => {
try {
observer.next(config)
} catch(err) {
observer.error(err);
} finally {
observer.complete();
}
})
}
and use it this way
var observable = createCustomObservable(config);
observable.subscribe((x) => console.log(x));

KnockOutJS trigger parent function on child subscribe

I am currently trying to learn KnockOutJS. I thought it would be a great idea to create a simple task-list application.
I do not want to write a long text here, let's dive into my problem. I appreciate all kind of help - I am new to KnockOutJS tho!
The tasks are declared as followed:
var Task = function (data) {
var self = this;
self.name = ko.observable(data.name);
self.status = ko.observable(data.status);
self.priority = ko.observable(data.priority);
}
And the view model looks like this
var TaskListViewModel = function() {
var self = this;
self.currentTask = ko.observable();
self.currentTask(new Task({ name: "", status: false, priority: new Priority({ name: "", value: 0 }) }));
self.tasksArr = ko.observableArray();
self.tasks = ko.computed(function () {
return self.tasksArr.slice().sort(self.sortTasks);
}, self);
self.sortTasks = function (l, r) {
if (l.status() != r.status()) {
if (l.status()) return 1;
else return -1;
}
return (l.priority().value > r.priority().value) ? 1 : -1;
};
self.priorities = [
new Priority({ name: "Low", value: 3 }),
new Priority({ name: "Medium", value: 2 }),
new Priority({ name: "High", value: 1 })
];
// Adds a task to the list
// also saves updated task list to localstorage
self.addTask = function () {
self.tasksArr.push(new Task({ name: self.currentTask().name(), status: false, priority: self.currentTask().priority() }));
self.localStorageSave();
self.currentTask().name("");
};
// Removes a task to a list
// also saves updated task list to localstorage
self.removeTask = function (task) {
self.tasksArr.remove(task);
self.localStorageSave();
};
// Simple test function to check if event is fired.
self.testFunction = function (task) {
console.log("Test function called");
};
// Saves all tasks to localStorage
self.localStorageSave = function () {
localStorage.setItem("romaTasks", ko.toJSON(self.tasksArr));
};
// loads saved data from localstorage and parses them correctly.
self.localStorageLoad = function () {
var parsed = JSON.parse(localStorage.getItem("romaTasks"));
if (parsed != null) {
var tTask = null;
for (var i = 0; i < parsed.length; i++) {
tTask = new Task({
name: parsed[i].name,
status: parsed[i].status,
priority: new Priority({
name: parsed[i].priority.name,
value: parsed[i].priority.value
})
});
self.tasksArr.push(tTask);
}
}
};
self.localStorageLoad();
}
What I want to do in my html is pretty simple.
All tasks I have added are saved to localStorage. The save function is, as you can see, called each time an element has been added & removed. But I also want to save as soon as the status of each task has been changed, but it is not possible to use subscribe here, such as
self.status.subscribe(function() {});
because I cannot access self.tasksArr from the Task class.
Any idea? Is it possible to make the self.tasksArr public somehow?
Thanks in advance!

Try this:
self.addTask = function () {
var myTask = new Task({ name: self.currentTask().name(), status: false, priority: self.currentTask().priority() })
myTask.status.subscribe(function (newValue) {
self.localStorageSave();
});
self.tasksArr.push(myTask);
self.localStorageSave();
self.currentTask().name("");
};