Binding javascript (d3.js) to shiny - javascript

First, I am fairly unfamiliar with javascript and its library d3.js, but I am familiar with R. Creating dashboards using Shiny has been fun and easy (thanks to stackoverflow). Now I want to expand it by connect d3 elements to it.
I'm looking for information sources on how to actually bind javascript to Shiny (R dashboard) and explain what is actually going on.
Background:
I did the tutorial on js and jquery on w3schools and learned (a bit) about d3 using Scott Murray's book (Interactive Data visualization for the web). I hoped this would be enough to make me understand the examples and explanation concerning how to build custom input/output bindings on the Shiny website:
http://shiny.rstudio.com/articles/building-inputs.html
But unfortunately I don't and I can't seem to find any examples which are in minimal working code. Many examples on github are to complex for me to dissect, most probably because of my little experience with javascript. Here is an examples of custom input binding with javascript:
https://github.com/jcheng5/shiny-js-examples/tree/master/input
Here is an example of an input & output binding I try to unfold:
<script src="http://d3js.org/d3.v3.js"></script>
<script type="text/javascript">
(function(){
// Probably not idiomatic javascript.
this.countValue=0;
// BEGIN: FUNCTION
updateView = function(message) {
var svg = d3.select(".d3io").select("svg")
svg.append("text")
.transition()
.attr("x",message[0])
.attr("y",message[1])
.text(countValue)
.each("end",function(){
if(countValue<100) {
countValue+=1;
$(".d3io").trigger("change");
}
})
}
// END: FUNCTION
//BEGIN: OUTPUT BINDING
var d3OutputBinding = new Shiny.OutputBinding();
$.extend(d3OutputBinding, {
find: function(scope) {
return $(scope).find(".d3io");
},
renderError: function(el,error) {
console.log("Foe");
},
renderValue: function(el,data) {
updateView(data);
console.log("Friend");
}
});
Shiny.outputBindings.register(d3OutputBinding);
//END: OUTPUT BINDING
//BEGIN: INPUT BINDING
var d3InputBinding = new Shiny.InputBinding();
$.extend(d3InputBinding, {
find: function(scope) {
return $(scope).find(".d3io");
},
getValue: function(el) {
return countValue;
},
subscribe: function(el, callback) {
$(el).on("change.d3InputBinding", function(e) {
callback();
});
}
});
Shiny.inputBindings.register(d3InputBinding);
//END: OUTPUT BINDING
})()
</script>
Where "d3io" is a div element in the ui, updateView() is a function. Here is the ui:
#UI
library(shiny)
d3IO <- function(inputoutputID) {
div(id=inputoutputID,class=inputoutputID,tag("svg","")) #; eerst zat ; erbij, maar werkt blijkbaar ook zonder
}
# Define UI for shiny d3 chatter application
shinyUI(pageWithSidebar(
# Application title
headerPanel("D3 Javascript chatter",
"Demo of how to create D3 I/O and cumulative data transfer"),
sidebarPanel(
tags$p("This widget is a demonstration of how to wire shiny direct to javascript, without any input elements."),
tags$p("Each time a transition ends, the client asks the server for another packet of information, and adds it
to the existing set"),
tags$p("I can't claim this is likely to be idiomatic javascript, because I'm a novice, but it allows d3 apps
to do progressive rendering. In real use, a more complex request/response protocol will probably be
required. -AlexBBrown")
),
mainPanel(
includeHTML("d3widget.js"),
d3IO("d3io") #Creates div element that d3 selects
)
))
Here is the server file:
# SERVER
library(shiny)
# Define server logic required to respond to d3 requests
shinyServer(function(input, output) {
# Generate a plot of the requested variable against mpg and only
# include outliers if requested
output$d3io <- reactive(function() {
if (is.null(input$d3io)) {
0;
} else {
list(rnorm(1)*400+200,rnorm(1)*400+200);
}
})
})
Specific questions:
1) The server.r seems to get input called "d3io" (input$d3io) since this is not defined in ui.r, I reasoned it must come from the javascript file. Which element does it actually refer to?
2) I have trouble understanding the custom binding part:
var d3OutputBinding = new Shiny.OutputBinding();
$.extend(d3OutputBinding, {
find: function(scope) {
return $(scope).find(".d3io");
},
renderError: function(el,error) {
console.log("Foe");
},
renderValue: function(el,data) {
updateView(data);
console.log("Friend");
}
});
Shiny.outputBindings.register(d3OutputBinding);
My understanding is:
Create a new shiny outputbinding, first find the class .d3io (div element), if error then write to console "Foe" (is this special code?), if not error then renderValue using the function updateView using data (Where does it receive this value from?) and write to console "Friend". Finally register output.
Hope you guys can help! I'm creating a document with the steps on "The necessary steps to learn how to implement javascript into shiny when you don't know any javascript", I would love that!:)
Cheers,
Long

Hi Sweetbabyjesus (so fun to say). You had two questions:
1) The server.r seems to get input called "d3io" (input$d3io) since this is not defined in ui.r, I reasoned it must come from the javascript file. Which element does it actually refer to?
That phrase input$d3io has the following components:
input is a parameter passed into the function - it's a list that
stores the current values of all the widgets in the app.
$ is the member selector.
d3io refers to the content of the div element with that id
('d3IO("d3io")') in the mainPanel of the UI.
2) I have trouble understanding the custom binding part:
var d3OutputBinding = new Shiny.OutputBinding();
That's right, this creates an instance of Shiny.OutputBinding and assigns it to the variable d3OutputBinding.
$.extend(d3OutputBinding, {
find: function(scope) {
return $(scope).find(".d3io");
},
renderError: function(el,error) {
console.log("Foe");
},
renderValue: function(el,data) {
updateView(data);
console.log("Friend");
}
});
This code extends the behaviour of d3OutputBinding with three functions called find, renderError and renderValue. Those three functions are required for a Shiny.OutputBinding.
find is the key because it returns a list of elements that should be passed into the two render functions via their el parameter. Notice it's returning elements whose css class is "d3io" - that's the same div mentioned earlier.
Note that extend() is a function of jQuery javascript library, and the $ in this context is an alias for the jQuery object.
Shiny.outputBindings.register(d3OutputBinding);
Lets Shiny know that this newly configured object should be put to use now.
Cheers, Nick

I'm going to take a step back and assume you want the amazing results D3 is capable of, but aren't necessarily tied to D3. Essentially, I'll be answering this question:
What are the necessary steps to learn how to implement JavaScript into Shiny when you don't know any JavaScript?
While D3 is amazingly powerful, it's also notoriously difficult to master - even for many folks who are quite comfortable with JavaScript. While I love D3 and use it almost every day, I'd recommend against it in this case. Instead, there's library called Plotly, which uses D3 in the background, but is built specifically for the scientific community and data scientists, so it's very friendly to the R community.
They have a thorough tutorial for connecting to Shiny and even have a ggplot2 converter if you're already familiar with that syntax, as many in the R world are. Unless your needs are very unusual, Plotly will likely serve your needs just as well as writing directly in D3, with a much more friendly learning curve.

Are you familiar with the rCharts package? It can work pretty well with Shiny and most of the output options are based on D3 variants. Two examples.

Very busy with work, I haven't had the chance to post it. Note that this is a workaround using the customMessageHandler (and I'm not using custom input/output binding). Here goes:
Objective: Send data from data frame to create a D3JS tree using customMessageHandler.
Path: I've managed to send data in data.frame format to a d3js tree. After you click the actionbutton, it changes the data in the data frame to JSON format, then sends it to the js file which creates the tree. The data of the tree is hard-coded on "server.r".
Where's the code? On my github!
https://github.com/SweetBabyJesus/shiny-d3js-simple-binding
Original: I created a tree algorithm based on CHAID to create insights from large datasets. People can upload their csv to the dashboard which then spits out the d3js tree:) The code is somewhat lengthy, therefore I cut it down for you and created a minimal code example.
Hope you like it.
Cheers,
Long

Related

react external javascript integration

I'm tring to merge 2 projects i found:
https://github.com/danxfisher/MeetEasier
and
this page https://tympanus.net/Development/Interactive3DMallMap/
i've done the changes in the react project meeteasier and included the html parts from interactivemallmap(with my little react abd nodejs knowledge) . I have problems on calling the javascript from main.js(interactivemallmap).
Here is the problem:
The first time i load the page with the chromedev i see that in the main.js it gets the values but when i recall the functions that values are null:
original main.js start like this and dot work:
;(function(window) {
...
mall = document.querySelector('.mall'),
...
pins = [].slice.call(mallLevelsEl.querySelectorAll('.map__space')),
....
pins.forEach(function(pin) {
var contentItem = contentEl.querySelector('.content__item[data- space="' + pin.getAttribute('data-space') + '"]');
pin.addEventListener('mouseenter', function() {
//if( !isOpenContentArea ) {
classie.add(contentItem, 'content__item--hover');
//}
});
....
})(window);
i've tried with the $(document).ready(function(){ instead of ;(function(window) {
but it is not working or better: in the first page load the it gets its value, but after when i pass over with the mouse and the event mouseenter triggers all the values are undefined
I think this is not the right approach but how do i make it work?
I do not have enough code to fully understand what is going on, but seeing that you're trying to merge two big projects with different codebases, if I were you I should take it slow, and take some steps back.
Your problem:
The main problem is that, to use React, you should first have a fundemental understanding of what it is doing under the hood.
You're trying to implement jQuery (a DOM library) with React, however, this will not work this easily, because React works with something that's called a virtual DOM, and it does not have access to the regular DOM nodes unless specifically ordered to do so (using findDOMNode from the react-dom package handles this for example).
What you should do:
Please read the docs first:
https://reactjs.org/docs/hello-world.html
Then, after you understand React, try implementing the SVG maps in it, step by step.
Just a small insight:
Rendering SVG in your render method, or try rebuilding it with D3 (https://d3js.org/) for example, just a suggestion on how to handle complex SVG.
You should handle most logic that's from main.js in the componentDidMount lifecycle, assuming you're going to need to access the map nodes.

Style node of Dabeng's OrgChart library

I am using the Dabeng Orgchart library, but I would like to customize the nodes, specifically creating a diamond instead of the squares they have in most examples. I have seen the createNode method, and I have found various CSS for creating a diamond but I can't figure out how to integrate it in dabeng org chart. What I want to do is display a diamond if some conditions are met, and the default square shapes if others are met. I have searched the web, but no example for changing the shape.
I am currently using the nodeTemplate attribute for the orgchart. Example:
var oc = $('#container').orgchart({
...
'nodeTemplate': orgTemplate,
...
});
In your orgtemplate function, data is whatever you have included in your orgchart data (in the example it would be name and title). You can stuff this object with other flags. For example, I have a chart in which I create new nodes and allow users to enter data into the node before committing it to the graph. I have a flag in my data object for data.isSaved to tell my template whether or not this node is saved or not. If it is saved, I have inline html checks (in AngularJS using ngIf's and the like, if you're familiar with AngularJS at all) to change the template based on the data.
In VanillaJS, you can just return pure HTML without the $compile and all that attached to pump in your own node template. You could actually do your check within the function for example:
function orgTemplate(data) {
if(data.isDiamond) {
return '<div class="diamond">...</div>';
} else {
return '<div class="square">...</div>';
}
}
I'm using AngularJS in my website so I define new scopes and use angular directives to make it more expandable. This is for reference for anyone else who stumbles upon this. My orgTemplate function is defined below.
function orgTemplate(data) {
var newScope = $scope.$new(true);
newScope.data = data;
return ( $compile('<div data-ng-include="\'.../template.html\'"></div>')(newScope));
}
Here's the orgChart Github as I'm sure you've browsed many times. If you look at the bottom you will see the nodeTemplate attribute definition I mention above. Hope this helps!
Side Note: I have had some trouble with styling when using custom templates, especially when defining different graph directions (i.e. 'l2r').
You can now customize your own node structure or shape with option "ndoeTemplate":
var nodeTemplate = function(data) {
return `
<span class="office">${data.office}</span>
<div class="title">${data.name}</div>
<div class="content">${data.title}</div>
`;
}
var oc = $('#chart-container').orgchart({
'data' : ds,
'nodeTemplate': nodeTemplate
});
Feel free to play around with this demo.
I would suggest you to use getorgchart instead it is highly customizable
http://www.getorgchart.com/Demos/Create-Your-Own-Theme-4

Domain Driven Design in Node.js Application

TL; DR;
I'm looking for trite example of DDD node.js application.
Hi,
I'm going to create node application. I wonder that I can not find any example of application with business logic separated in domain.
OK, there are some examples like:
https://github.com/adrai/node-cqrs-domain - but this is whole CQRS with event sourcing implementation.
My idea is to do that like that:
//domain/book.js
function Book(title, author)
{
this._title = title;
this._author = author;
}
// domain methods ...
//infrastructure/persistance/repository/book-repository.js
function BookRepository()
{}
BookRepository.prototype.save(book)
{
var bookModel = mappers.mapToOrm(book);
return bookModel.save();
}
// [...] get, getAll, getNextId
//infrastructure/persistance/orm/book.js
//using http://bookshelfjs.org/
var Book = bookshelf.Model.extend({
tableName: 'books'
});
//infrastructure/mappers/book-mapper.js
function mapToOrm(book) {
//mapping [...]
return new persistance.Book();
}
function mapToDomain(domain) {
//mapping [...]
return new domain.Book();
}
but on the other hand I've never seen any similar solution (with domain model, orm model, repository and mappers). Am I thinking in the right way? Maybe there is no reason to separate business logic in domain in node.js applications. If so, why? If not, can you send me an example of DDD implementation or improve my code?
[2017/01/13]
I've created sample application in TypeScript. For now without repositories and not much services. Issues and pull requests are welcome.
https://github.com/dawiddominiak/ddd-typescript-bin-packing-problem-solution
I'm very new to Node.js world.
But I believe if you do your work using TypeScript with Node you can force most of DDD principles to be used.
The problem "and advantage in the same time" in node.js that there aren't so restrictions like we have in OOP languages like C# or Java. and this freedom "and messy" of JavaScript making create robust complex DomainModel and Business logic very hard
I'm looking to do the same thing at the moment, and I'm coming from the Ruby world. So, let me do 2 things:
Point you to the best Ruby implementation I've seen of Domain-Driven Design I have found, Hanami: http://hanamirb.org/guides/models/overview/ which you could use as a reference.
Discuss what I'm finding (literally right now, as I type) to attempt to find the analogs in Node.
I've found this page: https://github.com/sindresorhus/awesome-nodejs
which catalogs a ton of high-quality / high-popularity Node packages.
The first thing is, we need something that is going to do validation and schema construction for our Domain Models. Just looking at the first entry in the data validation section, Joi seems to be a decent choice for that:
https://github.com/hapijs/joi
For Persistence of the domain objects, I'm just setting up a stub object, borrowing from Hanami's interface:
var repo = {
find: function(entity_name, id) {
// - Fetch an entity from the collection by its ID
},
create: function(entity_name, data) {
// – Create a record for the given data and return an entity
},
update: function(entity_name, id, data) {
// – Update the record corresponding to the id and return the updated entity
},
delete: function(entity_name, id) {
// – Delete the record corresponding to the given entity
},
all: function(entity_name) {
// - Fetch all the entities from the collection
},
query: function(entity_name, query_object) {
},
first: function(entity_name) {
// - Fetch the first entity from the collection
},
last: function(entity_name) {
// - Fetch the last entity from the collection
},
clear: function(entity_name) {
// - Delete all the records from the collection
}
}
module.exports = repo
whether you choose to use Bookshelf, Sequelize, or even the LoopBack framework, you can code an object that is going to fit the above interface that then does the dirty work of integrating with those frameworks.
If I were to try different ORM's, I would create a different repo object for each of the above. Notice that as I've written it, the repo is a singleton that is aware of different entities and how to persist them. In many cases, this will no doubt delegate to different repository objects on a per-entity basis. However, that might not always be true. a simple in-memory repo, could just have an array of objects for each entity.
That leaves Services/Interactors - The functions/classes that actually do work. These are easy - they are the ones that take a domain object, perform some business logic, and in the CRUD cases, make a call out to the Repository. A probably-syntactically-wrong example:
const repository = require('./myFileRepository')
function createBook(bookEntity) {
if(bookEntity.valid?) {
repository.create('book', bookEntity)
return true
}
else {
return { error: 'book not valid' }
}
}
module.exports = createBook
for the Service functions, I just today learned about Node Machines, and they seem like a really smart idea: http://node-machine.org
they seem to be a JS-attempt at monads + documentation. so I'm considering writing them up like that.
anyway, given it's been a year since your post, you've probably moved on. hope this helps you / the community!
Many would argue that JavaScript is NOT well suited to modeling a complex problem into a domain model and then into code. That's especially the case if the domain is in business, industry and commerce, rather than in computer or data science.
I'm not saying one can't create a domain model in JavaScript. Just like one could create one in C. But does that mean one should?
The example you give uses some terminology in domain-driven design, but misses the whole purpose and ethos of applying it.

Best way to organize jQuery/JavaScript code (2013) [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 9 years ago.
The Problem
This answer has been answered before but are old and not up to date. I have over 2000 lines of code in a single file, and as we all know this is bad practice, especially when i'm looking through code or adding new features. I want to better organize my code, for now and for the future.
I should mention that I'm building a tool (not a simple website) with lots of buttons, UI elements, drag, drops, action listeners/handlers and function in the global scope where several listeners may use the same function.
Example code
$('#button1').on('click', function(e){
// Determined action.
update_html();
});
... // Around 75 more of this
function update_html(){ .... }
...
More example code
Conclusion
I really need to organize this code for best use and not to repeat myself and be able to add new features and update old ones. I will be working on this by myself. Some selectors can be 100 lines of code others are 1. I have looked a bit at require.js and found it kinda repetitive, and actually writing more code than needed . I'm open to any possible solution that fit this criteria and link to resource / examples are always a plus.
Thanks.
I'll go over some simple things that may, or may not, help you. Some might be obvious, some might be extremely arcane.
Step 1: Compartmentalize your code
Separating your code into multiple, modular units is a very good first step. Round up what works "together" and put them in their own little encased unit. don't worry about the format for now, keep it inline. The structure is a later point.
So, suppose you have a page like this:
It would make sense to compartmentalize so that all the header-related event handlers/binders are in there, for ease of maintenance (and not having to sift through 1000 lines).
You can then use a tool such as Grunt to re-build your JS back to a single unit.
Step 1a: Dependency management
Use a library such as RequireJS or CommonJS to implement something called AMD. Asynchronous Module Loading allows you to explicitely state what your code depends on, which then allows you to offload the library-calling to the code. You can just literally say "This needs jQuery" and the AMD will load it, and execute your code when jQuery is available.
This also has a hidden gem: the library loading will be done the second the DOM is ready, not before. This no longer halts load-up of your page!
Step 2: Modularize
See the wireframe? I have two ad units. They'll most likely have shared event listeners.
Your task in this step is to identify the points of repetition in your code and to try to synthesise all this into modules. Modules, right now, will encompass everything. We'll split stuff as we go along.
The whole idea of this step is to go from step 1 and delete all the copy-pastas, to replace them with units that are loosely coupled. So, instead of having:
ad_unit1.js
$("#au1").click(function() { ... });
ad_unit2.js
$("#au2").click(function() { ... });
I will have:
ad_unit.js:
var AdUnit = function(elem) {
this.element = elem || new jQuery();
}
AdUnit.prototype.bindEvents = function() {
... Events go here
}
page.js:
var AUs = new AdUnit($("#au1,#au2"));
AUs.bindEvents();
Which allows you to compartmentalize between your events and your markup in addition to getting rid of repetition. This is a pretty decent step and we'll extend this further later on.
Step 3: Pick a framework!
If you'd like to modularize and reduce repetitions even further, there are a bunch of awesome frameworks around that implement MVC (Model - View - Controller) approaches. My favourite is Backbone/Spine, however, there's also Angular, Yii, ... The list goes on.
A Model represents your data.
A View represents your mark-up and all the events associated to it
A Controller represents your business logic - in other words, the controller tells the page what views to load and what models to use.
This will be a significant learning step, but the prize is worth it: it favours clean, modular code over spaghetti.
There are plenty of other things you can do, those are just guidelines and ideas.
Code-specific changes
Here are some specific improvements to your code:
$('.new_layer').click(function(){
dialog("Create new layer","Enter your layer name","_input", {
'OK' : function(){
var reply = $('.dialog_input').val();
if( reply != null && reply != "" ){
var name = "ln_"+reply.split(' ').join('_');
var parent = "";
if(selected_folder != "" ){
parent = selected_folder+" .content";
}
$R.find(".layer").clone()
.addClass(name).html(reply)
.appendTo("#layer_groups "+parent);
$R.find(".layers_group").clone()
.addClass(name).appendTo('#canvas '+selected_folder);
}
}
});
});
This is better written as:
$("body").on("click",".new_layer", function() {
dialog("Create new layer", "Enter your layer name", "_input", {
OK: function() {
// There must be a way to get the input from here using this, if it is a standard library. If you wrote your own, make the value retrievable using something other than a class selector (horrible performance + scoping +multiple instance issues)
// This is where the view comes into play. Instead of cloning, bind the rendering into a JS prototype, and instantiate it. It means that you only have to modify stuff in one place, you don't risk cloning events with it, and you can test your Layer stand-alone
var newLayer = new Layer();
newLayer
.setName(name)
.bindToGroup(parent);
}
});
});
Earlier in your code:
window.Layer = function() {
this.instance = $("<div>");
// Markup generated here
};
window.Layer.prototype = {
setName: function(newName) {
},
bindToGroup: function(parentNode) {
}
}
Suddenly, you have a way to create a standard layer from anywhere in your code without copy pasting. You're doing this in five different places. I've just saved you five copy-pastes.
One more:
// Ruleset wrapper for actions
var PageElements = function(ruleSet) {
ruleSet = ruleSet || [];
this.rules = [];
for (var i = 0; i < ruleSet.length; i++) {
if (ruleSet[i].target && ruleSet[i].action) {
this.rules.push(ruleSet[i]);
}
}
}
PageElements.prototype.run = function(elem) {
for (var i = 0; i < this.rules.length; i++) {
this.rules[i].action.apply(elem.find(this.rules.target));
}
}
var GlobalRules = new PageElements([
{
"target": ".draggable",
"action": function() { this.draggable({
cancel: "div#scrolling, .content",
containment: "document"
});
}
},
{
"target" :".resizable",
"action": function() {
this.resizable({
handles: "all",
zIndex: 0,
containment: "document"
});
}
}
]);
GlobalRules.run($("body"));
// If you need to add elements later on, you can just call GlobalRules.run(yourNewElement);
This is a very potent way to register rules if you have events that are not standard, or creation events. This is also seriously kick-ass when combined with a pub/sub notification system and when bound to an event you fire whenever you create elements. Fire'n'forget modular event binding!
Here is a simple way to split your current codebase into multiple files, using require.js.
I will show you how to split your code into two files. Adding more files will be straightforward after that.
Step 1) At the top of your code, create an App object (or whatever name you prefer, like MyGame):
var App = {}
Step 2) Convert all of your top-level variables and functions to belong to the App object.
Instead of:
var selected_layer = "";
You want:
App.selected_layer = "";
Instead of:
function getModified(){
...
}
You want:
App.getModified = function() {
}
Note that at this point your code will not work until you finish the next step.
Step 3) Convert all global variable and function references to go through App.
Change stuff like:
selected_layer = "."+classes[1];
to:
App.selected_layer = "."+classes[1];
and:
getModified()
to:
App.GetModified()
Step 4) Test Your code at this stage -- it should all work. You will probably get a few errors at first because you missed something, so fix those before moving on.
Step 5) Set up requirejs. I assume you have a web page, served from a web server, whose code is in:
www/page.html
and jquery in
www/js/jquery.js
If these paths are not exactly like this the below will not work and you'll have to modify the paths.
Download requirejs and put require.js in your www/js directory.
in your page.html, delete all script tags and insert a script tag like:
<script data-main="js/main" src="js/require.js"></script>
create www/js/main.js with content:
require.config({
"shim": {
'jquery': { exports: '$' }
}
})
require(['jquery', 'app']);
then put all the code you just fixed up in Steps 1-3 (whose only global variable should be App) in:
www/js/app.js
At the very top of that file, put:
require(['jquery'], function($) {
At the bottom put:
})
Then load page.html in your browser. Your app should work!
Step 6) Create another file
Here is where your work pays off, you can do this over and over.
Pull out some code from www/js/app.js that references $ and App.
e.g.
$('a').click(function() { App.foo() }
Put it in www/js/foo.js
At the very top of that file, put:
require(['jquery', 'app'], function($, App) {
At the bottom put:
})
Then change the last line of www/js/main.js to:
require(['jquery', 'app', 'foo']);
That's it! Do this every time you want to put code in its own file!
For your question and comments I'll assume you are not willing to port your code to a framework like Backbone, or use a loader library like Require. You just want a better way to orgainze the code that you already have, in the simplest way possible.
I understand it is annoying to scroll through 2000+ lines of code to find the section that you want to work on. The solution is to split your code in different files, one for each functionality. For example sidebar.js, canvas.js etc. Then you can join them together for production using Grunt, together with Usemin you can have something like this:
In your html:
<!-- build:js scripts/app.js -->
<script src="scripts/sidebar.js"></script>
<script src="scripts/canvas.js"></script>
<!-- endbuild -->
In your Gruntfile:
useminPrepare: {
html: 'app/index.html',
options: {
dest: 'dist'
}
},
usemin: {
html: ['dist/{,*/}*.html'],
css: ['dist/styles/{,*/}*.css'],
options: {
dirs: ['dist']
}
}
If you want to use Yeoman it will give you a boilerplate code for all this.
Then for each file itself, you need to make sure you follow best practices and that all the code and variables are all in that file, and don't depend on other files. This doesn't mean you can't call functions of one file from other, the point is to have variables and functions encapsulated. Something similar to namespacing. I'll assume you don't want to port all your code to be Object Oriented, but if you don't mind refactoring a bit, I'd recommend to add something equivalent with what is called a Module pattern. It looks something like this:
sidebar.js
var Sidebar = (function(){
// functions and vars here are private
var init = function(){
$("#sidebar #sortable").sortable({
forceHelperSize: true,
forcePlaceholderSize: true,
revert: true,
revert: 150,
placeholder: "highlight panel",
axis: "y",
tolerance: "pointer",
cancel: ".content"
}).disableSelection();
}
return {
// here your can put your "public" functions
init : init
}
})();
Then you can load this bit of code like this:
$(document).ready(function(){
Sidebar.init();
...
This will allow you to have a much more maintainable code without having to rewrite your code too much.
Use javascript MVC Framework in order to organize the javascript code in a standard way.
Best JavaScript MVC frameworks available are:
Backbone
Angular
CanJS
Ember
ReactJS
Selecting a JavaScript MVC framework required so many factors to consider. Read the following comparison article that will help you to select best framework based on the factors important for your project:
http://sporto.github.io/blog/2013/04/12/comparison-angular-backbone-can-ember/
You can also use RequireJS with the framework to support Asynchrounous js file & module loading.
Look the below to get started on JS Module loading:
http://www.sitepoint.com/understanding-requirejs-for-effective-javascript-module-loading/
Categorize your code. This method is helping me a lot and does work with any js framework:
(function(){//HEADER: menu
//your code for your header
})();
(function(){//HEADER: location bar
//your code for your location
})();
(function(){//FOOTER
//your code for your footer
})();
(function(){//PANEL: interactive links. e.g:
var crr = null;
$('::section.panel a').addEvent('click', function(E){
if ( crr) {
crr.hide();
}
crr = this.show();
});
})();
In your preferred editor (the best is Komodo Edit) you may fold in by collapsing all entries and you will see only the titles:
(function(){//HEADER: menu_____________________________________
(function(){//HEADER: location bar_____________________________
(function(){//FOOTER___________________________________________
(function(){//PANEL: interactive links. e.g:___________________
I would suggest:
publisher/subscriber pattern for event management.
object orientation
namespacing
In your case Jessica, divide the interface into pages or screens. Pages or screens can be objects and extended from some parent classes. Manage the interactions among pages with a PageManager class.
I suggest that you use something like Backbone. Backbone is a RESTFUL supported javascript library. Ik makes your code cleaner and more readable and is powerful when used together with requirejs.
http://backbonejs.org/
http://requirejs.org/
Backbone isn't a real library. It is meant to give structure to your javascript code. It is able to include other libraries like jquery, jquery-ui, google-maps etc. Backbone is in my opinion the closest javascript approach to Object Oriented and Model View Controller structures.
Also regarding your workflow.. If you build your applications in PHP use the Laravel library. It'll work flawlessly with Backbone when used with the RESTfull principle. Below the link to Laravel Framework and a tutorial about building RESTfull APIs:
http://maxoffsky.com/code-blog/building-restful-api-in-laravel-start-here/
http://laravel.com/
Below is a tutorial from nettuts. Nettuts has a lot of High Quality tutorials:
http://net.tutsplus.com/tutorials/javascript-ajax/understanding-backbone-js-and-the-server/
Maybe its time for you start implementing a whole development workflow using such tools as yeoman http://yeoman.io/. This will help control all your dependencies, build process and if you wanted, automated testing. Its a lot of work to start with but once implemented will make future changes a lot easier.

Event handling in Dojo

Taking Jeff Atwood's advice, I decided to use a JavaScript library for the very basic to-do list application I'm writing. I picked the Dojo toolkit, version 1.1.1. At first, all was fine: the drag-and-drop code I wrote worked first time, you can drag tasks on-screen to change their order of precedence, and each drag-and-drop operation calls an event handler that sends an AJAX call to the server to let it know that order has been changed.
Then I went to add in the email tracking functionality. Standard stuff: new incoming emails have a unique ID number attached to their subject line, all subsequent emails about that problem can be tracked by simply leaving that ID number in the subject when you reply. So, we have a list of open tasks, each with their own ID number, and each of those tasks has a time-ordered list of associated emails. I wanted the text of those emails to be available to the user as they were looking at their list of tasks, so I made each task box a Dijit "Tree" control - top level contains the task description, branches contain email dates, and a single "leaf" off of each of those branches contains the email text.
First problem: I wanted the tree view to be fully-collapsed by default. After searching Google quite extensively, I found a number of solutions, all of which seemed to be valid for previous versions of Dojo but not the one I was using. I eventually figured out that the best solution would seem to be to have a event handler called when the Tree control had loaded that simply collapsed each branch/leaf. Unfortunately, even though the Tree control had been instantiated and its "startup" event handler called, the branches and leaves still hadn't loaded (the data was still being loaded via an AJAX call). So, I modified the system so that all email text and Tree structure is added server-side. This means the whole fully-populated Tree control is available when its startup event handler is called.
So, the startup event handler fully collapses the tree. Next, I couldn't find a "proper" way to have nice formatted text for the email leaves. I can put the email text in the leaf just fine, but any HTML gets escaped out and shows up in the web page. Cue more rummaging around Dojo's documentation (tends to be out of date, with code and examples for pre-1.0 versions) and Google. I eventually came up with the solution of getting JavaScript to go and read the SPAN element that's inside each leaf node and un-escape the escaped HTML code in it's innerHTML. I figured I'd put code to do this in with the fully-collapse-the-tree code, in the Tree control's startup event handler.
However... it turns out that the SPAN element isn't actually created until the user clicks on the expando (the little "+" symbol in a tree view you click to expand a node). Okay, fair enough - I'll add the re-formatting code to the onExpand() event handler, or whatever it's called. Which doesn't seem to exist. I've searched to documentation, I've searched Google... I'm quite possibly mis-understanding Dojo's "publish/subscribe" event handling system, but I think that mainly because there doesn't seem to be any comprehensive documentation for it anywhere (like, where do I find out what events I can subscribe to?).
So, in the end, the best solution I can come up with is to add an onClick event handler (not a "Dojo" event, but a plain JavaScript event that Dojo knows nothing about) to the expando node of each Tree branch that re-formats the HTML inside the SPAN element of each leaf. Except... when that is called, the SPAN element still doesn't exist (sometimes - other times it's been cached, just to further confuse you). Therefore, I have the event handler set up a timer that periodically calls a function that checks to see if the relevant SPAN element has turned up yet before then re-formatting it.
// An event handler called whenever a "email title" tree node is expanded.
function formatTreeNode(nodeID) {
if (dijit.byId(nodeID).getChildren().length != 0) {
clearInterval(nodeUpdateIntervalID);
messageBody = dijit.byId(nodeID).getChildren()[0].labelNode.innerHTML
if (messageBody.indexOf("<b>Message text:</b>") == -1) {
messageBody = messageBody.replace(/>/g, ">");
messageBody = messageBody.replace(/</g, "<");
messageBody = messageBody.replace(/&/g, "&");
dijit.byId(nodeID).getChildren()[0].labelNode.innerHTML = "<b>Message text:</b><div style=\"font-family:courier\">"+messageBody+"</div>";
}
}
}
// An event handler called when a tree node has been set up - we changed the default fully-expanded to fully-collapsed.
function setupTree(theTree) {
dijit.byId("tree-"+theTree).rootNode.collapse();
messageNode = dijit.byId("tree-"+theTree).rootNode.getChildren();
for (pl = 0; pl < messageNode.length; pl++) {
messageNode[pl].collapse();
messageNode[pl].expandoNode.onclick = eval("nodeUpdateIntervalID = setInterval(\"formatTreeNode('"+messageNode[pl].id+"')\",200); formatTreeNode('"+messageNode[pl].id+"');");
}
}
The above has the feel of a truly horrible hack, and I feel sure I must have taken a wrong turn somewhere early on in my thought process. Can someone please tell me:
The correct way to go about putting nicely-formatted text inside a Dojo/Dijit Tree control.
The correct way to handle Dojo events, like where I can figure out what events are available for me to subscribe to.
A better JavaScript library to use (can I do what I want to with JQuery and avoid the all-around-the-houses approach seen above?).
PS: If you're naming a software project, give thought to its name's uniqueness in Google - I'm sure searching for "Dojo" documentation in Google would be easier without all the martial arts results getting in the way.
PPS: Firefox spellchecker knows how to spell "Atwood", correcting me when I put two 'T's instead of one. Is Jeff just that famous now?
I assume that you followed the dijit.Tree and dojo.data in Dojo 1.1 tutorial which directed you to pass the data to the tree control using a data store. That had me banging my head of a brick wall for a while.
Its not really a great approach and the alternative is not really well documented. You need to create a use model instead. I have included an example below of a tree model that I created for displaying the structure of an LDAP directory.
You will find the default implementation of the model in your dojo distribution at ./dijit/_tree/model.js. The comments should help you understand the functions supported by the model.
The IDirectoryService class the code below are stubs for server-side Java POJOs generated by Direct Web Remoting (DWR). I highly recommend DWR if you going to be doing a lot of client-server interaction.
dojo.declare("LDAPDirectoryTreeModel", [ dijit.tree.model ], {
getRoot : function(onItem) {
IDirectoryService.getRoots( function(roots) {
onItem(roots[0])
});
},
mayHaveChildren : function(item) {
return true;
},
getChildren : function(parentItem, onComplete) {
IDirectoryService.getChildrenImpl(parentItem, onComplete);
},
getIdentity : function(item) {
return item.dn;
},
getLabel : function(item) {
return item.rdn;
}
});
And here is an extract from the my JSP page where I created the model and used it to populate the tree control.
<div
dojoType="LDAPDirectoryTreeModel"
jsid="treeModel"
id="treeModel">
</div>
<div
jsid="tree"
id="tree"
dojoType="dijit.Tree" model="treeModel"
labelAttr="name"
label="${directory.host}:${directory.port}">
</div>

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