How do I test for an empty JavaScript object?
ECMA 5+: Note, though, that this creates an unnecessary array (the return value of keys). Pre-ECMA 5: jQuery: lodash: Underscore: Hoek ExtJS AngularJS (version 1) Ramda
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Open a URL in a new tab (and not a new window)
Nothing an author can do can choose to open in a new tab instead of a new window; it is a user preference. (Note that the default user preference in most browsers is for new tabs, so a trivial test on a browser where that preference hasn’t been changed will not demonstrate this.) CSS3 proposed target-new, but the … Read more
Remove element by id
The DOM is organized in a tree of nodes, where each node has a value, along with a list of references to its child nodes. So element.parentNode.removeChild(element) mimics exactly what is happening internally: First you go the parent node, then remove the reference to the child node. As of DOM4, a helper function is provided to do … Read more
How to read a local text file?
You need to check for status 0 (as when loading files locally with XMLHttpRequest, you don’t get a status returned because it’s not from a Webserver) And specify file:// in your filename:
Is it possible to write data to file using only JavaScript?
Some suggestions for this – If you are trying to write a file on client machine, You can’t do this in any cross-browser way. IE does have methods to enable “trusted” applications to use ActiveX objects to read/write file. If you are trying to save it on your server then simply pass on the text … Read more
Cannot open local file – Chrome: Not allowed to load local resource
We use Chrome a lot in the classroom and it is a must to working with local files. What we have been using is “Web Server for Chrome”. You start it up, choose the folder wishing to work with and go to URL (like 127.0.0.1:port you chose) It is a simple server and cannot use … Read more
Scroll to an element with jQuery
Assuming you have a button with the id button, try this example: I got the code from the article Smoothly scroll to an element without a jQuery plugin. And I have tested it on the example below.
What is lexical scope?
I understand them through examples. 🙂 First, lexical scope (also called static scope), in C-like syntax: Every inner level can access its outer levels. There is another way, called dynamic scope used by the first implementation of Lisp, again in a C-like syntax: Here fun can either access x in dummy1 or dummy2, or any x in any function that call fun with x declared in it. will print 5, will print 10. The … Read more
Tricky : ‘dict’ object is not callable
What you’ve run into is called “shadowing”. You’ve created an object in some namespace (either the global namespace of your module, or the local namespace of a function) that has the same name as a the builtin dict type. This prevents you from accessing the builtin dict in the usual way. You can still get to it, with a bit more … Read more