Month: March 2009

Is there a way to turn a normal Eclipse Project into a JPA Project?

I have a normal project with Entities in it and a Persistence.xml file, but it is not an eclipse recognized JPA project. What can I do?

Answer

project properties –> project facets.
There you can click on the JPA check-box and you have an JPA project.

For the past few years, I’ve been working on a team that does .NET and SQL Server. I’ll soon be joining a team that is Java and Oracle. What can I read/do to get up-to-speed.

Answer

This, similar, SO Thread might be helpful.

How do I do this?

Answer

You can execute anything you want from Python with the os.system() function.

os.system(command)
Execute the command
(a string) in a subshell. This is
implemented by calling the Standard C
function system, and has the same
limitations. Changes to os.environ,
sys.stdin, etc. are not reflected in
the environment of the executed
command.

For more power and flexibility you will want to look at the subprocess module:

The subprocess module allows you to
spawn new processes, connect to their
input/output/error pipes, and obtain
their return codes.

I’m a complete novice, looking for instructions on implementing javascript. I am attempting to replace a YUI slider with buttons and a text field. I am trying to achieve buttons that, when held down, will continue to make the text field increase, preferably at a faster and faster rate. (http://www.blackbird502.com/white.htm)I have this in the java tag in the head:

function holdit(btn, action, start, speedup) {
var t;

var repeat = function () {
    action();
    t = setTimeout(repeat, start);
    start = start / speedup;
}

btn.mousedown = function() {
    repeat();
}

btn.mouseup = function () {
    clearTimeout(t);
}

/* to use */
holdit(btn, function () { }, 1000, 2); 
/* x..1000ms..x..500ms..x..250ms..x */

I have no clue how to implement the press and hold into the following in the body:

<form><input type=button value="UP"  class="btn" onClick="javascript:this.form.amount.value++;"><br /><input type=text name=amount value=5 class="text"><br /> <input type=button value="DOWN"  class="btn" onClick="javascript:this.form.amount.value--;" ></form>

Is it possible? Thanks.

Answer

This code should do everything you’re looking for; it’s based very loosely on tj111’s example. I tried to make it as reusable as possible, and it doesn’t need JavaScript mixed in with the HTML.

You do need to add IDs to the buttons (btnUP and btnDOWN) and text field (amount). You can change these IDs in the window.onload statement.

// This function creates a closure and puts a mousedown handler on the element specified in the "button" parameter.
function makeButtonIncrement(button, action, target, initialDelay, multiplier){
    var holdTimer, changeValue, timerIsRunning = false, delay = initialDelay;
    changeValue = function(){
        if(action == "add" && target.value < 1000)
            target.value++;
        else if(action == "subtract" && target.value > 0)
            target.value--;
        holdTimer = setTimeout(changeValue, delay);
        if(delay > 20) delay = delay * multiplier;
        if(!timerIsRunning){
            // When the function is first called, it puts an onmouseup handler on the whole document 
            // that stops the process when the mouse is released. This is important if the user moves
            // the cursor off of the button.
            document.onmouseup = function(){
                clearTimeout(holdTimer);
                document.onmouseup = null;
                timerIsRunning = false;
                delay = initialDelay;
            }
            timerIsRunning = true;
        }
    }
    button.onmousedown = changeValue;
}

//should only be called after the window/DOM has been loaded
window.onload = function() {
    makeButtonIncrement(document.getElementById('btnUP'), "add", document.getElementById('amount'), 500, 0.7);
    makeButtonIncrement(document.getElementById('btnDOWN'), "subtract", document.getElementById('amount'), 500, 0.7);
}

I developed a web application, that permits my users to manage some aspects of a web site dynamically (yes, some kind of cms) in LAMP environment (debian, apache, php, mysql)

Well, for example, they create a news in their private area on my server, then this is published on their website via a cURL request (or by ajax).

The news is created with an WYSIWYG editor (fck at moment, probably tinyMCE in the next future).

So, i can’t disallow the html tags, but how can i be safe?
What kind of tags i MUST delete (javascripts?)?
That in meaning to be server-safe.. but how to be ‘legally’ safe?
If an user use my application to make xss, can i be have some legal troubles?

Answer

If you are using php, an excellent solution is to use HTMLPurifier. It has many options to filter out bad stuff, and as a side effect, guarantees well formed html output. I use it to view spam which can be a hostile environment.