live code examples: cytoscape.js initialization -- incomplete? - javascript

Being brand new to cytoscape.js, I may be missing something obvious. Please forgive me if that is so.
I am studying the first example offered here:
reached from this page
Three files are offered -- HTML, CSS, JavaScript -- along with the impression that these three will, when loaded into my browser, create a running example.
But the HTML seems to be incomplete, possibly in two ways:
the JavaScript on the jsbin page needs to be included via a script tag
the variable cy is not defined anywhere that I can see, leading to this error message in the console: Object #cy has no method cytoscape
A stack overflow search on that error message points back to the very fine cy.js documentation, but alas, I am still in the dark: where do I initialize the "cy" object?
And best of all, where can I find a complete working example, useful for such a raw beginner as myself, something I can pore over and study until I begin to grasp the logic of this style of programming, and make use of this very fine library?
Thanks!

Your first example is indeed a fully working example. Just use the menu to the top left. Choose File -> Download. This will download a single HTML-file, that works out of the box.
The file is called jsbin.ravecala.1.html. Open with
firefox jsbin.ravecala.1.html
(I also struggled a while before realizing this.)

I really don't know what's your JavaScript & jQuery knowledge level, but it seems you may need to practice it all a little.
Yes, if you're referring to the following tag:
<script src="http://cytoscape.github.io/cytoscape.js/api/cytoscape.js-latest/cytoscape.min.js"></script>
This is indeed necessary, as it is the basis of cytoscape.js, the library itself, wich allows, for instance, add the method cytoscape to the variable #cy, as you mentioned in your second point.
The variable #cy is the div itself. jQuery refers to objects IDs this way, with #. So:
<div id="cy"></div>
Can be referred as $("#cy"). Wich adds the cytoscape function to it is the library itself.
I think that this live example is really good, although the one you linked is more basic and appropriate to get known with the basic structure and initialization of cytoscape.js. I suggest you to get known with jQuery (this course was really clear to me) and read the cytoscape.js documentation, which is full of rich examples.

Related

Library to display JS object in HTML in a way debuggers do

Currently I am looking for efficient (means made by someone else) way to represent JS objects inside HTML page. Ideally I should provide arbitrary object and library should make dropdown or popup with all properties of that object that can be selected and viewed as well. Final goal is to make object representation as close to modern JS debugger interface as possible.
In case if I didn't get my point accross I want to find libarary that would allow to represent object on web page as on picture below.
So I would like to ask if any of you know a libarary that can help me to do this.
Update: I found that firebug-lite-debug.js has similar functionality but such approach requires unknown amount of work to extract code I need
Upadate: I ended up using json-formatter-js. It is able to render any js object and do it in lasy way so only expanded part of object is taken into account. Therefore gigantic things as window can be displayed.
It sounds like you just want a pre-made widget that will display an object as HTML?
I'd probably start with something like html-stringify
It spits out a mostly clean HTML string with basic formatting. You could use that directly in your page, or add some additional styles to help match the style of your page. You can try it out on RunKit to see if it'll meet your needs.
(RunKit is a nice way to try out packages like this, so you can see what the output looks like without having to install them.)

How can I find jquery/javascript/modernizer code responsible for a effect

I'm learning web design, and there is no better method than redoing others work. So I'm reading other pages code, but it's so hard to find the jQuery, Javascript or modernizer or ... code responsible for the effect.
I'm using firebug, also used firequery, but the problem is they give me the event but not the code and a big tree of DOM, I don't know where even I look into it.
I really don't care which event is triggered, but I do care how the code is written. If I find the code so I can understand the event is on click or on focus...
Or let's say a website has a some javascript file, linked to a website. when I load the webpage i get a webpage consist of DOM and external/internal script. When I see a cool effect and want to read the code, I run firebug, inspect element to find the element. After that I don't know what to do? I can't search for selector or event in the script because maybe the developer of the site used different selector that I'm searching. Sometimes I find the code, but it's so jammed, not in human readable form, I don't know how to change the code to something indent and neat
The problem becomes more dramatic when the website using other java framework than jQuery.
I've searched a lot, used many tools, but couldn't find anything useful, please with your advice light my way to learn web developing
edit:--
I found a way but I'm sure there should be a better way outside
first in chrome I inspect the element to find the corresponding element, then i right click and check all the break point on it(if it doesn't work i do the same for parent element)
after that i play with that element to trigger the function and it break
usually the function that called the method is down in the callstack
also for reading
also for reading the script i use pretty print of chrome, i used some online prettyfier but most of them has limitation in number of character, for a long script none of the google first page resault is good enough. so the only good option here is for now is chrome, anyone have any other method?
It is difficult to learn how to do things just from inspecting it, as many effects may be implemented entirely in JavaScript, which may be deep, hidden away in a source file.
You mention that the code is not in human readable form, beautifying it may help:
https://stackoverflow.com/a/6318092/1061602
Most 'visual' effects should be able to be viewable from the CSS, e.g. JQuery Mobile's buttons, it is possible to see how the different classes are combined, ui-shadow, ui-btn, ui-disabled etc
Otherwise, searching for selectors is pretty much all you can do. Personally, if I am learning, looking at too much code at one time can be overwhelming. Also a lot of the UI effects may be difficult to trace.
My advice is, perhaps a better way around it would be to try and describe one single effect that you require, and then search on Google or Stack Overflow for guidance on how to create that effect.
The usual documentation sources will be useful:
http://www.w3schools.com/css3/default.asp
http://api.jquery.com/
Happy learning!

Simple lightbox feedback form? Included screenshot

There are so many lightboxes to choose from, I'm looking for a very lightweight one to use in an embedded javascript widget that would be a single domain name. I saw the perfect one on chainreactioncycles.com, it popped up out of nowhere so I took a screenshot:
I tried looking for info on it on the page source, but couldn't find anything that would let me trace where it came from... Would anybody know of one like this? Or exactly that one?
If not exactly like above, anything similar would be great too, keeping the following in mind:
Very small javascript download (animation not needed)
Self contained, not dependent on any libraries other than jquery (since I'm already using that anyway).
Works in major browsers
Close button (like GetSatisfaction or UserVoice)
Dims background
Avoids javascript namespace conflicts (or can easily be made to avoid them)
CSS styling of lightbox does not interfere with site styling
Have you used an existing lightbox scripts for this same purpose with similar requirements? Did you roll your own? Insights welcome!
What you are looking for is called a modal box.
Here is a list of them
... and here is a striking replica of what you are looking for
Check out Zoombox.. It sounds like what you're looking for... Simple to use... Allows custom content.. jQuery Module... From past experience it covers what you have outlined as requirements etc
http://www.grafikart.fr/zoombox will tell you all you need to know.

What does JpegMini use to animate the image comparison on the homepage?

Hopefully the title is clear. I'm talking about the large image comparison slider on the homepage of JpegMini.
I've managed to identify it as needing three core files (written as they are named on the site):
jquery.min.js
jquery-ui-1.8.14.min.js
scripts-0135.min.js
It's this last one I'm unable to find any information about so it may hold the secrets but I don't know.
Anyone got any ideas?
The .imagePairs elements have a mousemove event bound:
$('.imagePairs').data('events').mousemove[0].handler
is a function.
The code is apparent inside scripts-0135.min.js, but it is minified.
What you can do is parsing it through jsbeautifier and see if you can make something out of it. It will still have variable names which make no sense, so it will not be easy.
Looking at the code, it seems like they initialize it with $('.imagePairs').myBeforeAfter, which is most probably the function that handles the effect.
I never was able to determine the script used, in the end I searched the web and found a suitable alternative which came with good documentation. http://www.catchmyfame.com/2009/06/25/jquery-beforeafter-plugin/

javascript rollover effects question

I am learning JS currently with a js book.
A rollover effects example got me, so I need some help.
I upload a snapshot on Flickr.com. The url is : http://www.flickr.com/photos/58745632#N05/5389380030/
The left side of the snapshot is the page and the right side of the snapshot is the javascript code.
My question is can I change the content in the red box to the codes in the green box.
If I can, why does the author bother to add this line "thisLink.imgToChange = thisImage"?
And what is the relationship between "thisLink.imgToChange" and "thisImage"?
Are they the same one or are they identical ones?
Could someone explain it for me?
Thank you very much.
thisImage is the reference to an image object. It is being passed as a variable to the function.
An image object has properties like the source (.src), .width. height etc.
thisLink is also an object, and it can have properites too. So, thisLink.imgToChange = thisImage sets the "imgToChange" to the image fed into the function. imgToChange is a completely arbitrary property chosen by the programmer. It's being used stash some data used later.
All this code demonstrates the "hard way" of doing a rollover. Having to type (or even use) "document.getElementById" over and over again all of this is a pain. Most of the time we depend on scripts to automate these things.
Frameworks, which are basically optimized versions of the type of code you're working on here, were developed to take care of the dirty work. The most popular framework, by far, is jQuery.
Doing pretty well the same thing using jQuery can be done in one line of code.
Here's another posting as an example.
Short answer:
.imgToChange and thisImg refer to the same place. .imgToChange is added as a property so it's easy to use later, like in the onmouseout function.
UPDATE
Regarding your comment: It won't work either way (probably).
Since setupRollover() is called multiple times, the variable thisImage will point to a different image node every time it's called. The code in the green box will only be applied to the most recent thisImage.
The red box uses this because that means "the object that fired the event". The red box sets up each object to refer to the appropriate image. Then, when this is moused over, the correct image is changed.
Try it out yourself, it's easier to see than to explain.
Given that this is straight out of JavaScript & Ajax for the Web: Visual QuickStart Guide, 7th edition1, what in particular are you having trouble with in the (line-by-line) explanation on pages 96-97?
1 Co-written by me, btw.

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