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Javier Neira

How To Make Firebug's JavaScript Debugger Break Inside Dynamic JavaScript Using The 'de... - 0 views

beerpla.net/...debugger-keyword-ie-chrome-too

shared by Javier Neira on 19 Dec 09 - Cached
  • The Problem With Dynamic JavaScript However, what if the JavaScript file where you need to set breakpoints is not static but instead dynamic (generated on the fly). If you set a breakpoint in this case and reload the page, the breakpoint will most likely disappear, especially if the JavaScript url is generated uniquely every time. The Solution If you have access to the source, the solution comes in the form of the debugger; keyword. Just add it to your dynamic JavaScript generator or into any JavaScript file you have access to exactly where you want Firebug to break, and voila – it does.
  • More so, this method also works in Google Chrome and IE (if you have Microsoft Script Debugger)
  • Javier Neira on 19 Dec 09
     
    The Problem With Dynamic JavaScript However, what if the JavaScript file where you need to set breakpoints is not static but instead dynamic (generated on the fly). If you set a breakpoint in this case and reload the page, the breakpoint will most likely disappear, especially if the JavaScript url is generated uniquely every time. The Solution If you have access to the source, the solution comes in the form of the debugger; keyword. Just add it to your dynamic JavaScript generator or into any JavaScript file you have access to exactly where you want Firebug to break, and voila - it does.
Hussain M Elius

Better Coda Slider - 0 views

jqueryfordesigners.com/...coda-slider.html

javascript jquery coda slider

shared by Hussain M Elius on 01 Jan 09 - Cached
  • This technique demonstrates an accessible 'Coda'-like slider interface, but in addition, allows you to place links to the sliding content anywhere on the page and have the effect (and navigation) still work.
  • Hussain M Elius on 01 Jan 09
     
    This technique demonstrates an accessible 'Coda'-like slider interface, but in addition, allows you to place links to the sliding content anywhere on the page and have the effect (and navigation) still work.
Javier Neira

Accessing a MySQL database from Node.JS « Devthought - 2 views

devthought.com/...g-a-mysql-database-from-nodejs

mysql access javascript slayer node.js

shared by Javier Neira on 09 Dec 09 - Cached
  • Javier Neira on 09 Dec 09
     
    connection.query("SELECT * FROM TABLE").addCallback(function(result){ for (var i = 0, l = result.ROWS.length; i < l; i++){ var row = result.ROWS[i]; // do something with the data } });
Javier Neira

JavaScript EE, Part 1: Run JavaScript files on the server side - 0 views

www.ibm.com/...wa-aj-javaee

j2ee javascript jdk 1.6 server client ajax

shared by Javier Neira on 04 Jun 09 - Cached
  • freedom to use the same JavaScript routines on both servers and clients. In addition, the techniques presented throughout this series will allow you to maintain a single code base for both Ajax and non-Ajax clients
  • This double-coding issue can be avoided by using JavaScript combined with Java code on the server side, getting full support of scripting languages through the javax.script API. In addition, the Java SE Development Kit (JDK) 6 already includes Mozilla's Rhino JavaScript engine, which means no setup is required.
  • the toSource() method, which all JavaScript objects must have.
  • ...5 more annotations...
  • engine.eval(scriptReader, vars);
  • sun.org.mozilla.javascript.internal.NativeObject
  • all data exchange between the Java code and the executed script should be done through primitive variables, strings, and Java objects (for example, beans) whose properties and methods can be accessed very easily in the JavaScript code. Simply said, don't try to access native JavaScript objects in your Java code. Use Java objects in the JavaScript code instead.
  • Note that javax.script.Invocable is an optional interface, which some script engines may not implement. The JavaScript engine that comes with JDK 6 does support this interface.
  • you can significantly reduce the execution time by compiling the scripts, using the methods provided by another optional interface named javax.script.Compilable, which is supported by the JavaScript engine of JDK 6.
Julian Knight

Jash: JavaScript Shell - 4 views

www.billyreisinger.com/jash

javascript programming development bookmarklet

shared by Julian Knight on 12 May 11 - Cached
  • Julian Knight on 12 May 11
     
    "Jash is a DHTML-based window that gives you command-line JavaScript access to the current browser window. With this console you can quickly debug scripts, manipulate the DOM, view the current page's objects, functions, and variables, execute arbitrary Javascript, enter new CSS (in IE, Firefox, Opera, and Safari), and much more." - A useful tool to execute JavaScript, make live (temporary) CSS changes to a page, discover the page structure, etc. for developers. Written totally in JavaScript so can be used on any platform with any browser. Include in your own pages for debugging or load via a bookmarklet to run on any page.
Javier Neira

Is JavaScript object-oriented? - Stack Overflow - 1 views

stackoverflow.com/...is-javascript-object-oriented

oop javascript discusion stackoverflow

shared by Javier Neira on 29 Oct 09 - Cached
  • Well this is broken. Since the function assigned to getValue is no longer in scope with _value it can't access it. We would need to promote _value to an attribute of this but that would make it accessable outside of the control of code written for the class, hence encapsulation is broken.
Ivan Pavlov

Service Mapping Description Proposal - JSON Schema - 0 views

groups.google.com/...e-mapping-description-proposal

javascript

shared by Ivan Pavlov on 21 Mar 08 - Cached
  • Ivan Pavlov on 21 Mar 08
     
    A Service Mapping Description (SMD) is a JSON representation describing web services. An SMD can defines the various aspects of a web service such that clients can coherently interact with the web services. An SMD can be used by generic tools to generate interfaces, human and programmatic, to access available web services. A wide array of web services can be described with SMD including REST services and JSON-RPC services. The SMD format is designed to be flexible, compact, simple, readable, and easily implemented.
Ivan Pavlov

JNEXT - JavaScript Native Extensions - 0 views

jnext.org

javascript

shared by Ivan Pavlov on 06 Oct 08 - Cached
  • JNEXT is an open source (triple MPL, GPL, LGPL license), small footprint, cross platform and cross browser framework for extending Web browser Javascript (for more background and motivation check this blog entry). With JNEXT it is possible to utilize existing Web browsers to host full and self contained applications that do not depend on external Web servers for the application logic (although they are free to make use of them). This is acheived by enabling Javascript controlled access to the full range of native operating system resources (such as TCP/UDP sockets, files, databases, threads etc).
yc c

JavaScript Shell - 0 views

www.squarefree.com/shell

bookmarklet debug dom javascript shell tools

shared by yc c on 31 May 07 - Cached
  • yc c on 31 May 07
     
    Features: You can enter statements and expressions at the same prompt. The result of each non-void statement or expression is shown. User-defined variables. b = document.body User-defined functions. function f() { return 5; } JavaScript error messages are shown in red. Previous statements and expressions are available through Up and Down arrow keys. Tab completion. Multiline input (Shift+Enter to insert a line break). If the shell is opened using a bookmarklet, JavaScript typed into the shell runs in the context of the original window. Works well in Firefox, mostly works in Opera 8 and in IE 6 for Windows. Suggested uses: Test short bits of JavaScript, bookmarklets, or user scripts. (For longer bits of JavaScript, try the JavaScript development enviornment too.) Explore DOM objects such as document.body using props (Alt+P) to figure out what is possible. Explore the DOM of a specific page using the bookmarklet version of the shell. Modify the DOM of a specific page using the bookmarklet version of the shell. Use the shell like you would use the home screen of a calculator such as a TI-83. Alt+M gives you easy access to math functions such as sin and pow.
Vincent Tsao

Javascript Closures - 0 views

jibbering.com/...closures.html

closure javascript programming reference

shared by Vincent Tsao on 17 Jun 08 - Cached
  • The simple explanation of a Closure is that ECMAScript allows inner functions; function definitions and function expressions that are inside the function bodes of other functions. And that those inner functions are allowed access to all of the local variables, parameters and declared inner functions within their outer function(s).
Julian Knight

DOMAss - The DOM assistant - Robert's talk - 0 views

www.robertnyman.com/...domass-the-dom-assistant

development html imported delicious javascript programming scripting

shared by Julian Knight on 29 Aug 08 - No Cached
  • Julian Knight on 29 Aug 08
     
    JS library to standardise access to the DOM
Javier Neira

InfoQ: ECMAScript 5 released - 1 views

www.infoq.com/...ecmascript5

javascript ecmascript 5 features

shared by Javier Neira on 12 Dec 09 - Cached
  • The introduction of strict mode aims to avoid common coding problems in ECMAScript applications. This is achieved with the presence of a lone string literal in a unit (script or function): "use strict;"
  • for either the entire script (if at the top of the script) or for a single function (if the first part of a function).
  • var i=3 is needed
  • ...10 more annotations...
  • and introducing new variables through eval cannot occu
  • delete cannot be used against arguments, functions or variables or other properties with the configurable flag set to false
  • with statements, often a source of errors, are no longer used and considered syntax errors
  • Functions can no longer have duplicate arguments with the same name Objects can no longer have duplicate properties with the same name
  • Access to the global object becomes a runtime error
  • A new JSON object with parse and stringify to support efficient generation of JSON data; like eval but without the security implications of being able to reduce code
  • Array now has standard functions, such as indexOf(), map(), filter(), and reduce()
  • Object now has seal()
  • and freeze()
  • Object.getPrototypeof() returns the prototype of the given object
Javier Neira

Perfection kills » Understanding delete - 3 views

perfectionkills.com/understanding-delete

javascript delete tutorial

shared by Javier Neira on 11 Jan 10 - Cached
yc c liked it
  • All because it’s not possible to delete variables in Javascript. At least not when declared in such way.
  • It’s almost as if Firebug follows some other rules of deletion. It is Firebug that has led Stoyan astray! So what is really going on here?
  • we need to understand how delete operator works in Javascript: what exactly can and cannot be deleted and why.
  • ...35 more annotations...
  • var o = { x: 1 }; delete o.x; // true o.x; // undefined
  • var x = 1; delete x; // false x; // 1
  • function x(){} delete x; // false typeof x; // "function"
  • Note that delete only returns false when a property can not be deleted.
  • variable instantiation and property attributes
  • Global code, Function code and Eval code.
  • When a source text is treated as a Program, it is executed in a global scope, and is considered a Global code.
  • Anything that’s executed directly within a function is, quite obviously, considered a Function code. In browsers, content of event attributes (e.g. &lt;p onclick="..."&gt;) is usually parsed and treated as a Function code.
  • text that’s supplied to a built-in eval function is parsed as Eval code. We will soon see why this type is special.
  • And now that we know the difference between property assignment and variable declaration — latter one sets DontDelete, whereas former one doesn’t — it should be clear why undeclared assignment creates a deletable property:
  • As you can see, execution contexts can logically form a stack. First there might be Global code with its own execution context; that code might call a function, with its own execution context; that function could call another function, and so on and so forth. Even if function is calling itself recursively, a new execition context is being entered with every invocation.
  • Every execution context has a so-called Variable Object associated with it. Similarly to execution context, Variable object is an abstract entity, a mechanism to describe variable instantiation. Now, the interesing part is that variables and functions declared in a source text are actually added as properties of this Variable object.
  • When control enters execution context for Global code, a Global object is used as a Variable object. This is precisely why variables or functions declared globally become properties of a Global object:
  • The behavior is actually very similar: they become properties of Variable object. The only difference is that when in Function code, a Variable object is not a Global object, but a so-called Activation object. Activation object is created every time execution context for Function code is entered.
  • and a special Arguments object (under arguments name). Note that Activation object is an internal mechanism and is never really accessible by program code.
  • within Eval code are created as properties of calling context’s Variable object. Eval code simply uses Variable object of the execution context that it’s being called within:
  • Execution context When ECMAScript code executes, it always happens within certain execution context.
  • When declared variables and functions become properties of a Variable object — either Activation object (for Function code), or Global object (for Global code), these properties are created with DontDelete attribute. However, any explicit (or implicit) property assignment creates property without DontDelete attribute. And this is essentialy why we can delete some properties, but not others:
  • Special arguments variable (or, as we know now, a property of Activation object) has DontDelete. length property of any function instance has DontDelete as well:
  • As you might remember, undeclared assignment creates a property on a global object.
  • Now that it’s clear what happens with variables (they become properties), the only remaining concept to understand is property attributes. Every property can have zero or more attributes from the following set — ReadOnly, DontEnum, DontDelete and Internal. These attributes serve as sort of flags — an attribute can either exist on a property or not. For the purposes of today’s discussion, we are only interested in DontDelete.
  • Variables declared within Eval code are actually created as properties without DontDelete:
  • This interesting eval behavior, coupled with another aspect of ECMAScript can technically allow us to delete non-deletable properties. The thing about function declarations is that they can overwrite same-named variables in the same execution context:
  • Note how function declaration takes precedence and overwrites same-named variable (or, in other words, same property of Variable object). This is because function declarations are instantiated after variable declarations, and are allowed to overwrite them
  • If we declare function via eval, that function should also replace that property’s attributes with its own. And since variables declared from within eval create properties without DontDelete, instantiating this new function should essentially remove existing DontDelete attribute from the property in question, making that property deletable (and of course changing its value to reference newly created function).
  • Unfortunately, this kind of spoofing doesn’t work in any implementation I tried. I might be missing something here, or this behavior might simply be too obscure for implementors to pay attention to
  • this.x = 1; delete x; // TypeError: Object doesn't support this action
  • var x = 1; delete this.x; // TypeError: Cannot delete 'this.x'
  • It’s as if variable declarations in Global code do not create properties on Global object in IE.
  • Not only is there an error, but created property appears to have DontDelete set on it, which of course it shouldn’t have:
  • “The global variable object is implemented as a JScript object, and the global object is implemented by the host.
  • Note how this and window seem to reference same object (if we can believe === operator), but Variable object (the one on which function is declared) is different from whatever this references.
  • delete doesn’t differentiate between variables and properties (in fact, for delete, those are all References) and really only cares about DontDelete attribute (and property existence).
  • The moral of the story is to never trust host objects.
  • Few restrictions are being introduced. SyntaxError is now thrown when expression in delete operator is a direct reference to a variable, function argument or function identifier. In addition, if property has internal [[Configurable]] == false, a TypeError is thrown:
seth kutcher

The Best Remote PC Support I Ever Had - 1 views

The Remote PC Support Now excellent remote PC support services are the best. They have skilled computer tech professionals who can fix your PC while you wait or just go back to work or just simpl...

remote PC support

started by seth kutcher on 12 Sep 11 no follow-up yet
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