Delete multiple Objects at once on a fabric.js canvas in html5 - javascript

I'm actually working on a html5 canvas project which uses the fabric.js Framework for the canvas interactions. Now I'm struggeling with the deletion of multiple objects. The following code does not seem to track the selected objects, but tracks all objects on the canvas.
var deleteSelectedObject = document.getElementById('delete-item');
deleteSelectedObject.onclick = function(){
var curSelectedObjects = new Array();
curSelectedObjects = canvas.getObjects(canvas.getActiveGroup);
canvas.discardActiveGroup();
for (var i = 0; i < curSelectedObjects.length; i++){
canvas.setActiveObject(curSelectedObjects[i]);
canvas.remove(canvas.getActiveObject());
}
};
Don't get my failure.

Due to #Kangax comment which solved most of the problem, I found the following solution to delete the currently selected objects from the canvas.
var deleteSelectedObject = document.getElementById('delete-item');
deleteSelectedObject.onclick = function()
{
if(canvas.getActiveGroup()){
canvas.getActiveGroup().forEachObject(function(o){ canvas.remove(o) });
canvas.discardActiveGroup().renderAll();
} else {
canvas.remove(canvas.getActiveObject());
}
};
The function checks whether a group is selected. If a group is selected every object of the group gets removed.
If no group is selected the function tries to remove a selected object. If nothing is selected, the canvas is not changed.

Your code seems like it is selecting and then de-selecting the objects.
This may work better:
var deleteSelectedObject = document.getElementById('delete-item');
deleteSelectedObject.onclick = function()
{
var curSelectedObjects = canvas.getObjects(canvas.getActiveGroup);
canvas.discardActiveGroup();
for (var i = 0; i < curSelectedObjects.length; i++)
{
canvas.remove(curSelectedObjects[i]);
}
};
Good information link:
https://github.com/kangax/fabric.js/wiki/Tutorial-2#wiki-modifying-objects

You can check any object property and can remove
var objects = canvas.getObjects();
for (var i = 0; i < objects.length; ) {
if (objects[i].name == 'cropArea' || objects[i].name == 'bleedLine') {
canvas.remove(objects[i]);
i = 0;
} else {
i++;
}
}

I done this:
var selectedObj = canvas.getObjects(canvas.getActiveGroup())
return me the array of the selected objects. :)
the last function paranthesis is missing in your code snippet

None of the solutions above (or anywhere elese on stackoverflow) worked for me except for this one solution I found on jsfiddle:
function deleteObjects(){
var activeObject = canvas.getActiveObject(),
activeGroup = canvas.getActiveGroup();
if (activeObject) {
if (confirm('Are you sure?')) {
canvas.remove(activeObject);
}
}
else if (activeGroup) {
if (confirm('Are you sure?')) {
var objectsInGroup = activeGroup.getObjects();
canvas.discardActiveGroup();
objectsInGroup.forEach(function(object) {
canvas.remove(object);
});
}
}
}
http://jsfiddle.net/beewayne/z0qn35Lo/

Did you know that canvas.remove can take more than one parameter? So the easiest way should be this one:
canvas.remove(...canvas.getObjects());
Other than canvas.clear this will only remove the objects in the canvas and not also the background.

Related

How to read back data from LocalStorage

Once checkbox is active there are various <p> tags that get class "result". What I do with them is following:
function submit(){
alert("in submit");
var user_choice = document.getElementsByClassName("result");
for (var i = 0; i < user_choice.length; i++){
console.log(user_choice[i].innerHTML);
}
localStorage.setItem('storage',user_choice);
}
I hope this makes an HTMLcollection. After that, at submitted.html page (redirect there after pressing submit button) I wanna console.log all the items. So I write this:
window.onload = function() {
if ( localStorage.getItem('storage')) {
var got_user_choice = localStorage.getItem('storage');
for (var i = 0; i < got_user_choice.length; i++){
console.log(got_user_choice[i].innerHTML);
}
}
}
As long as it's a HTMLcollection (read array) I operate with it in terms of array. But what I get in console is just undefined. What's wrong with my code?
Local storage can only contain strings, not DOM elements. You should make an array of all the elements, and convert that to JSON.
function submit(){
alert("in submit");
var user_choice = document.getElementsByClassName("result");
var html = [];
for (var i = 0; i < user_choice.length; i++){
console.log(user_choice[i].innerHTML);
html.push(user_choice[i].innerHTML);
}
localStorage.setItem('storage',JSON.stringify(html));
}

How to update JavaScript array dynamically

I have an empty javascript array(matrix) that I created to achieve refresh of divs. I created a function to dynamically put data in it. Then I created a function to update the Array (which I have issues).
The Data populated in the Array are data attributes that I put in a JSON file.
To better undertand, here are my data attributes which i put in json file:
var currentAge = $(this).data("age");
var currentDate = $(this).data("date");
var currentFullName = $(this).data("fullname");
var currentIDPerson = $(this).data("idPerson");
var currentGender = $(this).data("gender");
Creation of the array:
var arrayData = [];
Here is the function a created to initiate and addind element to the Array :
function initMatrix(p_currentIDPerson, p_currentGender, p_currentFullName, p_currentDate, p_currentAge) {
var isFound = false;
// search if the unique index match the ID of the HTML one
for (var i = 0; i < arrayData.length; i++) {
if(arrayData[i].idPerson== p_currentIDPerson) {
isFound = true;
}
}
// If it doesn't exist we add elements
if(isFound == false) {
var tempArray = [
{
currentIDPerson: p_currentIDPerson,
currentGender: p_currentGender,
currentFullName: p_currentFullName,
currentDate: p_currentDate, currentAge: p_currentAge
}
];
arrayData.push(tempArray);
}
}
The update function here is what I tried, but it doesn't work, maybe I'm not coding it the right way. If you can help please.
function updateMatrix(p_currentIDPerson, p_currentGender, p_currentFullName, p_currentDate, p_currentAge) {
for (var i = 0; i < arguments.length; i++) {
for (var key in arguments[i]) {
arrayData[i] = arguments[i][key];
}
}
}
To understand the '$this' and elm: elm is the clickableDivs where I put click event:
(function( $ ) {
// Plugin to manage clickable divs
$.fn.infoClickable = function() {
this.each(function() {
var elm = $( this );
//Call init function
initMatrixRefresh(elm.attr("idPerson"), elm.data("gender"), elm.data("fullname"), elm.data("date"), elm.data("age"));
//call function update
updateMatrix("idTest", "Alarme", "none", "10-02-17 08:20", 10);
// Définition de l'evenement click
elm.on("click", function(){});
});
}
$('.clickableDiv').infoClickable();
}( jQuery ));
Thank you in advance
Well... I would recommend you to use an object in which each key is a person id for keeping this list, instead of an array. This way you can write cleaner code that achieves the same results but with improved performance. For example:
var myDataCollection = {};
function initMatrix(p_currentIDPerson, p_currentGender, p_currentFullName, p_currentDate, p_currentAge) {
if (!myDataCollection[p_currentIDPerson]) {
myDataCollection[p_currentIDPerson] = {
currentIDPerson: p_currentIDPerson,
currentGender: p_currentGender,
currentFullName: p_currentFullName,
currentDate: p_currentDate,
currentAge: p_currentAge
};
}
}
function updateMatrix(p_currentIDPerson, p_currentGender, p_currentFullName, p_currentDate, p_currentAge) {
if (myDataCollection[p_currentIDPerson]) {
myDataCollection[p_currentIDPerson] = {
currentGender: p_currentGender,
currentFullName: p_currentFullName,
currentDate: p_currentDate,
currentAge: p_currentAge
};
}
}
Depending on your business logic, you can remove the if statements and keep only one function that adds the object when there is no object with the specified id and updates the object when there is one.
I think the shape of the resulting matrix is different than you think. Specifically, the matrix after init looks like [ [ {id, ...} ] ]. Your update function isn't looping enough. It seems like you are trying to create a data structure for storing and updating a list of users. I would recommend a flat list or an object indexed by userID since thats your lookup.
var userStorage = {}
// add/update users
userStorage[id] = {id:u_id};
// list of users
var users = Object.keys(users);

Javascript HTML include results in duplicate includes in random places

This problem has me absolutely stumped. I'm trying to include HTML snippets with Javascript and it works, but for some reason it decides to also include duplicate snippets in various other locations.
Here is a screenshot of what I mean:
It also varies the number and location of these random includes.
This is the function I use to include. It searches through the document and finds div elements with the attribute include="x.html"
function include() {
var allElements;
var fileName;
var includeRequest;
allElements = document.getElementsByTagName("*");
for (var i = 0; i < allElements.length; i++) {
if (allElements[i].getAttribute("include")) {
fileName = allElements[i].getAttribute("include");
includeRequest = new XMLHttpRequest();
includeRequest.open("GET", fileName, true);
includeRequest.onreadystatechange = function() {
if (includeRequest.readyState == 4 && includeRequest.status == 200) {
allElements[i].removeAttribute("include");
allElements[i].innerHTML = includeRequest.responseText;
include();
delete includeRequest;
includeRequest = null;
}
}
includeRequest.send();
return;
}
}
}
This is the function that gets tags from an html file containing articles, and adds them to the list of tags in the box on the right. As you can see, in one place the footer is added to the list instead of the tag. I don't know why.
function getTags() {
var taglist = document.getElementById("taglist");
var tagsRequest = new XMLHttpRequest();
tagsRequest.open("GET", "blogstubs.html", true);
tagsRequest.responseType = "document";
tagsRequest.onreadystatechange = function() {
if (tagsRequest.readyState == 4 && tagsRequest.status == 200) {
var tagsResponse = tagsRequest.responseXML;
var tags = tagsResponse.getElementsByClassName("tag");
var tags = getUnique(tags);
var len = tags.length;
for (var i = 0; i < len; i++) {
var li = document.createElement("li");
li.appendChild(tags[i]);
taglist.appendChild(li);
}
delete tagsRequest;
tagsRequest = null;
}
}
tagsRequest.send();
}
Javascript only solution please. Ideas?
I copied your website (I hope you don't mind) and tested it with my changes, it seems to be working now without this bug. Here's what I did:
1) I created a new function, don't forget to change the name to whatever you prefer:
function newFunction(allElements, includeRequest) {
allElements.removeAttribute("include");
allElements.innerHTML = includeRequest.responseText;
include();
delete includeRequest;
includeRequest = null;
}
2) I changed the include() function to look like this:
function include() {
var allElements;
var fileName;
var includeRequest;
allElements = document.getElementsByTagName("*");
for (var i = 0; i < allElements.length; i++) {
if (allElements[i].getAttribute("include")) {
var element = allElements[i];
fileName = element.getAttribute("include");
includeRequest = new XMLHttpRequest();
includeRequest.open("GET", fileName, true);
includeRequest.onreadystatechange = function() {
if (includeRequest.readyState == 4 && includeRequest.status == 200) {
return newFunction(element, includeRequest);
}
}
includeRequest.send();
return;
}
}
}
I think the problem was caused by async nature of AJAX requests, like I said in the comment. So you need to pass the variables to your AJAX call instead of using the global scope, that's why you need this new callback function.
In other words, in the original code the AJAX variable allElements[i] wasn't in sync with your loop's allElements[i], so while in your loop it would be 5, in AJAX function (which executed separately and not in order with the loop) it would be 3, 6 or whatever else. That is why it would append the html to the element that seems random. Think of AJAX as of someone who doesn't care about the order of your loops, someone who really doesn't like to wait while someone else is counting and does everything in his own order.

Storin a variable with many id's in array

var arrayOfId[] = $scope.rep.Selected.id;
I have this code. My question is if I had a some id's in $scope...Selected.id and then I make this (code) all these id's will be in every other array or in one array?
$scope.delIt = function () {
if ($scope.rep.Selected > 0) {
$scope.rep.Selected = true;
} else {
$scope.rep.Selected = false
}
var arrayOfId [] = $scope.rep.Selected.id;
for(i=0; i<=arrayOfId[i]; i++){
$http.delete("http://localhost:3000/users/" +arrayOfId[]);
}
}
This is full code. I wanted to send request every single id wich is stored in $scope.rep.Selected.id

Check if team already added

I have a page where you can invite teams. Clicking "Invite teams" makes a popup box appear showing a search input. The search-function is AJAX based. When a team is found through your search word(s), you'll have to click on the team whereupon the team will be showed in a "Invited-teams"-box.
It works in a way that when you "add" the team, a hidden input field is generated containing the team's ID as a value. The problem is that with my current code, it is possible to add the same team as many times as you wish. I should be possible to check, if the team can be found in the hidden-input-data. If it already exists, it should not be possible to add the sane team.
My current javascript-code can be found beneath here. Please notice that I have tried to make the code that checks the team, but it doesn't work.
function addTeam(tid) {
// Grab the input value
var teamName = document.getElementById(tid).innerHTML;
var teamID = document.getElementById(tid).id;
// If empty value
if(!teamName || !teamID) {
alert('An error occured.');
} else {
//Tried to do the "team-adlready-added"-test, but it doesn't work
var stored_teams = $t('#store-teams').getElementsByTagName('input');
for (var i = 0; i < stored_teams.length; i++) {
var stored_team = stored_teams[i];
if(stored_team.value == teamID) {
break;
var team_already_added = 1;
}
alert(team_already_added);
}
if((team_already_added) || team_already_added != 1) {
// Store the team's ID in hidden inputs
var store_team = document.createElement('input');
store_team.type = 'hidden';
store_team.value = teamID;
// Append it and attach the event (via onclick)
$t('#store-teams').appendChild(store_team);
// Create the teams with the value as innerHTML
var div = document.createElement('div');
div.className = 'team-to-invite';
div.innerHTML = teamName;
// Append it and attach the event (via onclick)
$t('#teams').appendChild(div);
}
div.onclick = removeTeam;
}
return false;
}
Thanks in advance.
I just want to give you a hint for a possible solution without html elements.
You can create a new functional object for team:
var Team = function (id, name) {
this.name = name;
this.id = id;
}
Create an array which will contain teams:
var TeamList = [];
Add you Teams:
TeamList.push(new Team(1, "Team 1"));
TeamList.push(new Team(2, "Team 2"));
TeamList.push(new Team(3, "Team 3"));
TeamList.push(new Team(4, "Team 4"));
Write a function which loops trough the list of teams and checks with the id if a team already exists:
function containsTeam(id) {
for (var i = 0; i < TeamList.length; i++) {
if (TeamList[i].id == id) {
return true;
}
}
return false;
}
Just check it:
containsTeam(1); //returns true
containsTeam(5); //returns false
Have a look at the jsFiddle DEMO and open the console to see the output.
EDIT: In addition, to remove an element you can write a function which looks pretty much the same as the containsTeam function. Just use array.splice instead of returning true:
function removeTeam(id) {
for (var i = 0; i < TeamList.length; i++) {
if (TeamList[i].id == id) {
TeamList.splice(i, 1);
}
}
}
And remove a team:
removeTeam(3);
Your variable scope is off.
You declare team already added in the wrong spot.
Declare it with team name and team id and it will get you in the right direction

Categories

Resources