jsTree 3 - select next / previous node of dynamically loaded tree - javascript

I have a jsTree with lazy loading. I want to be able to select the next and previous nodes using an external function. The api suggests tree.get_next_dom() but this only seem to work on nodes that have already been loaded, not ones that may require loading first.
$("[href='#next']").click(function () {
var tree = $('#container').jstree(true),
curr = tree.get_selected(false);
tree.deselect_all();
var n = tree.get_next_dom(curr);
tree.select_node(n);
});
see full fiddle for a example showing the lazy load ..
http://jsfiddle.net/6L7twnka/3/
So "next" would see if the node had children and then expand it, loading if required. Previous would have to look at get_prev_dom and then expand it and then possibly expand all the last nodes inside it (recursively) in order to then put the selection on the most immediately previous node. I got a bit lost trying to do this.

Maybe I've already solved, but I leave here a suggestion.
After the method call "tree.deselect_all ();" you invoke the "tree.open_all ()" method.
$ ("[href = '# next']"). click (function () {
var tree = $ ('# container'). jstree (true)
curr = tree.get_selected (false);
tree.deselect_all ();
tree.open_all ();
var n = tree.get_next_dom (curr);
tree.select_node (n);
});
Sincerely,
Charles Oliveira

Related

Vis.js network: how to add a node on click inside the canvas?

Manipulation methods of vis.js only include addNodeMode(), but not something like addNode(). I wonder if there's some nice way to create a node on click. May be by manipulating the data instead of network itself?
Of'course, one may go
network.on('click',function(params){
if((params.nodes.length == 0) && (params.edges.length == 0)) {
network.addNodeMode(); // doesn't add, one more click needed
//# generate click in the same place. Use params.pointer.canvas
// or params.pointer.DOM to set appropriate coordinates
}
})
but then we have also to prevent infinit loops since we generate a click event in a click handler..
Ok, here's my current implementation:
...
data = ...
nodes = new vis.DataSet(data.nodes); // make nodes manipulatable
data = { nodes:nodes, edges:edges };
...
var network = new vis.Network(container, data, options);
network.on('click',function(params){
if((params.nodes.length == 0) && (params.edges.length == 0)) {
var updatedIds = nodes.add([{
label:'new',
x:params.pointer.canvas.x,
y:params.pointer.canvas.y
}]);
network.selectNodes([updatedIds[0]]);
network.editNode();
}
})
It's not perfect since it actually creates a node and starts editing it, so if we cancel editing, the node stays. It also creates unwanted shadows of nodes. But it's already a working prototype which is enough to start with.
You can add nodes dynamically by using the update method of the vis.DataSet class. See this documentation page for details: https://visjs.github.io/vis-data/data/dataset.html

Kendo Treeview Expanding big tree issue

I have created a tree control using kendo TreeView.it has more than 10,000 nodes and i have used loadOnDemand false when creating Tree.
I am providing a feature to expand the tree by its level, for this i have created a method which takes the parameter "level" as number and expand it accordingly and user can enter 15 (max level) into the method, it works fine with 500 to 600 nodes for all the levels but when tree has more than 5000 nodes than if user is trying to expand above the 2nd level nodes then browser hangs and shows not responding error.
Method which i have created to expand the tree is :-
function ExapandByLevel(level, currentLevel) {
if (!currentLevel) {
currentLevel = 0;
}
if (level != currentLevel) {
var collapsedItems = $("#treeView").find(".k-plus:visible");
if (collapsedItems.length > 0) {
setTimeout(function () {
currentLevel++;
var $tree = $("#treeView");
var treeView = $tree.data("kendoTreeView");
var collapsedItemsLength = collapsedItems.length;
for (var i = 0; i < collapsedItemsLength; i++) {
treeView.expand($(collapsedItems[i]).closest(".k-item"));
}
ExapandByLevel(level, currentLevel);
}, 100);
}
else {
//console.timeEnd("ExapandByLevel");
hideLoading();
}
}
if (level == currentLevel) {
hideLoading();
}
}
call above given method like this:-
ExapandByLevel(15);
here 15 is level to expand in tree.
when tree has more than 5000 nodes than if user is trying to expand above the 2nd level nodes then browser hangs and shows not responding error.
please suggest any way to do this,what i want is expand the tree which can contains more than 5000 nodes.
I had a similar problem with kendo TreeView, when I wanted to load a tree with 30,000 nodes. The browser would freeze for a long time to load this number of nodes even when loadOnDemand was set to true.
So we decided to implement the server-side functionality for expanding nodes, and that's what you should do. You need to have 2 changes in your existing code.
Change your tree use server side Expand method.
When you call expand, you should make sure the node is expanded.
These two steps will be explained below. The thing you should know is, this way your browser doesn't hang at all, but it may take some time to complete the operation, because there will be so many webservice calls to the server.
Change your tree to use server side Expand method:
Please see Kendo UI's demos for Binding to Remote Data in this
link. Note that loadOnDemand should be set to true. In addition the server side Expand web service should be implemented too.
When you call expand, you should make sure the node is expanded:
In order to do this, there should be an event like Expanded defined in Kendo UI TreeView, but unfortunately there is none, except Expanding event. Using setTimeout in this case is not reliable, because the network is not reliable. So we ended up using a while statement to check that the node's children are created or not. There might be a better solution for this, however this satisfies our current requirement. Here's the change you should make when expanding nodes:
if (collapsedItems.length > 0) {
currentLevel++;
var $tree = $("#treeView");
var treeView = $tree.data("kendoTreeView");
var collapsedItemsLength = collapsedItems.length;
for (var i = 0; i < collapsedItemsLength; i++) {
var node = $(collapsedItems[i]).closest(".k-item")
if (!node.hasChildren)
continue; // do not expand if the node does not have children
treeView.expand(node);
// wait until the node is expanded
while (!node.Children || node.Children.length == 0);
}
ExapandByLevel(level, currentLevel);
}
You can also do the expand calls in a parallel way in order to decrease the loading time, but then you should change the way you check if all the nodes are expanded or not. I just wrote a sample code here that should work fine.
Hope this helps.
The solution to your problem is pretty simple: Update the version of Kendo UI that you are using since they have optimized (a loooooooooot) the code for HierarchicalDataSource and for TreeView.
Check this: http://jsfiddle.net/OnaBai/GHdwR/135/
This is your code where I've change the version of kendoui.all.min.js to v2014.1.318. I didn't even changed the CSS (despite you should). You will see that opening those 5000 nodes is pretty fast.
Nevertheless, if you go to 10000 elements you will very likely consider it slow but sorry for challenging you: do you really think that 10000 nodes tree is User Friendly? Is a Tree the correct way of presenting such a huge amount of data?

JS vs DOM timing: .remove() element visually happens, but travesal still includes it

The short description of the functionality that we are trying to achieve: we have a list of source objects on the left, a person can drag new items from the list to a list on the right, items thus get added to the list on the right; they can also remove items from the list on the right. The list on the right then gets saved whenever it is changed. (I don't think the specifics of how/where it is being saved matter...)
I am having a problem with a bit of timing in the JavaScript vs. DOM elements realm of things. Items that are already on the list on the right can be removed. We have some code that fires on a 'remove/delete' type icon/button on a DOM element, that is supposed to remove the element from the DOM visually and permanently (i.e. it doesn't need to be brought back with a 'show'). This visual change should then also show up in the JSON object that is built when the JS traverses the DOM tree to build the new updated list.
However, this chunk of JS code that runs immediately after this .remove() is called, the element that should have just been removed still shows up in the JSON object. This is not good.
Here are what I believe to be the relevant bits of code operating here. This lives in a web browser; much of this is in the document.ready() function. A given list can also have subsections, hence the sub-list parts and loops.
The on-click definition:
$('body').on('click', '.removeLine', function() {
var parent=$(this).parent().parent().parent(); //The button is a few DIVs shy of the outer container
var List=$(this).closest('article'); //Another parent object, containing all the
parent.fadeOut( 300,
function() {
parent.slideUp(300);
parent.remove();
}
);
sendList(List); // This builds and stores the list based on the DOM elements
});
And then later on, this function definition:
function sendList(List) {
var ListArray=[],
subListArray=[],
itemsArray = [],
subListName = "";
var ListTitle = encodeText(List.find('.title').html());
// loop through the subLists
List.find('.subList').each(
function(index, element) {
subListName=($(this).find('header > .title').html()); // Get sublist Title
subListID=($(this).attr('id')); // Get subList ID
// loop through the line items
itemsArray=[];
$(this).find('.itemSearchResult').each(
function(index, element) {
// Build item Array
if( $(this).attr('data-itemid')!= item ) {
itemArray.push( $(this).attr('data-itemid'));
}
}
);
// Build SubList Array with items Array
subListArray.push(
{
"subListName": subListName,
"subListID" : subListID,
"items" : itemsArray
}
);
}
); <!-- end SubList Loop -->
// Complete List Array with subListArray
ListArray ={
"ListName": ListTitle,
"ListID": List.attr('id'),
"subLists": subListArray
};
// Send New List to DataLists Object - the local version of storage
updateDataLists(ListArray);
// Update remote storage
window.location= URLstring + "&$Type=List" + "&$JSON=" + JSON.stringify(ListArray) + "&$objectID=" + ListArray.ListID;
};
It seems to be the interaction of the 'parent.remove()' step and then the call to 'sendList()' that get their wires crossed. Visually, the object on screen looks right, but if we check the data being sent to the storage, it comes through WITH the object that was visually removed.
Thanks,
J
PS. As you can probably tell, we are new at the Javascript thing, so our code may not be terribly efficient or proper. But...it works! (Well, except for this issue. And we have run into this issue a few times. We have a workaround for it, but I would rather understand what is going on here. Learn the deeper workings of JS so we don't create these problems in the first place.)
There's a few things going on here, but I'm going to explain it by approaching it from an asynchronous programming perspective.
You are calling sendList before the element gets removed from the DOM. Your element doesn't get removed from the DOM until after your fadeOut callback gets executed (which takes 300ms).
Your sendList function gets called immediately after you begin the fadeOut, but your program doesn't wait to call sendList until your fadeOut is finished - that's what the callback is for.
So I would approach it by calling sendList in the callback, after your DOM element has been removed like this:
$('body').on('click', '.removeLine', function() {
var el = $(this); //maintain a reference to $(this) to use in the callback
var parent=$(this).parent().parent().parent(); //The button is a few DIVs shy of the outer container
parent.fadeOut( 300,
function() {
parent.slideUp(300);
parent.remove();
sendList(el.closest('article'));
}
);
});

onClick replace /segment/ of img src path with one of number of values

No idea what I'm doing or why it isn't working. Clearly not using the right method and probably won't use the right language to explain the problem..
Photogallery... Trying to have a single html page... it has links to images... buttons on the page 'aim to' modify the path to the images by finding the name currently in the path and replacing it with the name of the gallery corresponding to the button the user clicked on...
example:
GALLERY2go : function(e) {
if(GalleryID!="landscapes")
{
var find = ''+ findGalleryID()+'';
var repl = "landscapes";
var page = document.body.innerHTML;
while (page.indexOf(find) >= 0) {
var i = page.indexOf(find);
var j = find.length;
page = page.substr(0,i) + repl + page.substr(i+j);
document.body.innerHTML = page;
var GalleryID = "landscapes";
}
}
},
There's a function higher up the page to get var find to take the value of var GalleryID:
var GalleryID = "portfolio";
function findGalleryID() {
return GalleryID
}
Clearly the first varGalleryID is global (t'was there to set a default value should I have been able to find a way of referring to it onLoad) and the one inside the function is cleared at the end of the function (I've read that much). But I don't know what any of this means.
The code, given its frailties or otherwise ridiculousness, actually does change all of the image links (and absolutely everything else called "portfolio") in the html page - hence "portfolio" becomes "landscapes"... the path to the images changes and they all update... As a JavaScript beginner I was pretty chuffed to see it worked. But you can't click on another gallery button because it's stuck in a loop of some sort. In fact, after you click the button you can't click on anything else and all of the rest of the JavaScript functionality is buggered. Perhaps I've introduced some kind of loop it never exits. If you click on portfolio when you're in portfolio you crash the browser! Anyway I'm well aware that 'my cobbled together solution' is not how it would be done by someone with any experience in writing code. They'd probably use something else with a different name that takes another lifetime to learn. I don't think I can use getElement by and refer to the class/id name and parse the filename [using lots of words I don't at all understand] because of the implications on the other parts of the script. I've tried using a div wrapper and code to launch a child html doc and that come in without disposing of the existing content or talking to the stylesheet. I'm bloody lost and don't even know where to start looking next.
The point is... And here's a plea... If any of you do reply, I fear you will reply without the making the assumption that you're talking to someone who really hasn't got a clue what AJAX and JQuery and PHP are... I have searched forums; I don't understand them. Please bear that in mind.
I'll take a stab at updating your function a bit. I recognize that a critique of the code as it stands probably won't help you solve your problem.
var currentGallery = 'landscape';
function ChangeGallery(name) {
var imgs = document.getElementsByTagName("img") // get all the img tags on the page
for (var i = 0; i < imgs.length; i++) { // loop through them
if (imgs[i].src.indexOf(currentGallery) >= 0) { // if this img tag's src contains the current gallery
imgs[i].src = imgs[i].src.replace(currentGallery, name);
}
}
currentGallery = name;
}
As to why I've done what I've done - you're correct in that the scope of the variables - whether the whole page, or only the given function, knows about it, is mixed in your given code. However, another potential problem is that if you replace everything in the html that says 'landscape' with 'portfolio', it could potentially change non-images. This code only finds images, and then replaces the src only if it contains the given keyword.

How do I prevent the Javascript InfoVis SpaceTree `ST.select()` method from collapsing nodes?

I'm using the JavaScript InfoVis Toolkit and in particular the SpaceTree visualisation.
I need to expand all of the tree and then show a path from a particular leaf node back to the root.
I've got the tree to expand just fine but it's the selection of a leaf node and highlighting the path back to the root that's causing me some problems.
I'm using the ST.select(node, onComplete) function to select the leaf node I'm interested in and indeed the path back to the root (lines and nodes) are highlighted.
To do this I implemented the onBeforePlotNode and onBeforePlotLine ST.Controller methods to allow me to highlight the nodes back to the root and their plotlines:
onBeforePlotNode: function(node){
//add some color to the nodes in the path between the
//root node and the selected node.
if (node.selected) {
node.data.$color = "#dddddd";
} else {
delete node.data.$color;
}
},
onBeforePlotLine: function(adj){
if (adj.nodeFrom.selected && adj.nodeTo.selected) {
adj.data.$color = "#33CC33";
adj.data.$lineWidth = 5;
} else {
delete adj.data.$color;
delete adj.data.$lineWidth;
}
}
The problem is that when I call ST.select() to highlight the leaf node all child nodes beneath this level are collapsed/hidden.
To see this in action I've uploaded a couple of examples:
Full tree expansion - leaf not selected
Leaf selected - path shown, but all children below node N2 missing
You may need to scroll down if your browser window is a bit small.
So my question is, how do I show nodes from a leaf node back to the root node in JavaScript InfoVis without collapsing level 3's children (level 1 being the root)?
If there was a way to find my leafe node and walk the tree back to the root (setting styles on the way) then I'd be happing doing that
OK after digging through all that code, cluttering it with console.log() calls and breakpoints, I found it.
It has to do with the inital onClick call, the fact that the graph as an update loop that's running in the background and the fact that everything besides onClick seems to ignore the busy state of the graph.
What happens
onClick gets called and triggers a chain of events, part of them is asynchronous
select is being called which is more or less synchronous and does its work
onClick finally gets done and one of it's side effects is that it re-expands the graph
select has set clickedNode and now onClick uses the newly set value of it and screws up
Solution
We need to redesign select so it respects the busy state of the graph:
select: function(id, onComplete) {
var that = this;
if (this.busy) {
window.setTimeout(function() {
that.select(id, onComplete);
}, 1);
return;
}
// original select code follows here (remove the old var that = this; assignment)
That's all, we simply check for the busy state and delay select until it's false.
This should also be applied to all other function besides onClick that are called from the outside, the library designer here did a bad job of indicating what has side effects and what has not though.
Did you try setting "constrained: false" in ST's properties? That solved it for me.
http://thejit.org/static/v20/Docs/files/Visualizations/Spacetree-js.html

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