Hi! I’m Starx

Question 1

Question by Edward Tanguay

I allow PDF files to be uploaded to my site (PHP).

I would like to offer the ability to also allow .zip files which contain PDF files in directories so it is easier for users to simply zip a directory and upload one file instead of uploading multiple zip files individual.

For those of you who offer a .zip file upload feature to your (PHP) website, what are the technical, security, and other issues you have faced?

Answer

Answer by Starx

Starx

AFAIK, php can handle zip files pretty efficiently. Difficulties/Issues that I can think of is, while accessing the file where We need to extract the zip first, and then retrieve the actual needed file. Due to that reason, extracting a zip, might consume additional amount of server time, depending on the size of the file itself.

Where As, during uploads, I do not suppose there is any difficulties or issues specially emphasized on zip types.

Question 2

Question by hbase_user

hbase_user

How to find whether a json array is empty or not using PHP?
empty($jsonarray) seems doesn’t work!

Answer

Answer by Starx

Starx

Try this

if(count(json_decode($jsonarray,1))==0) {
    echo "empty";
}

//or
if(empty(json_decode($jsonarray,1))) {
    echo "empty";
}

Question 3

Question by selvin

selvin

I want to give a div a glassy reflection appearance as well as a semi transparent effect. How can I combine these two effects so that the div will look like a glassy transparent gadget? Is there a way to do this?

The div’s bgcolor is lightskyblue and no background image is set yet.

enter image description here

Answer

Answer by Starx

Starx

You can give alpha tranparency in your background color.

For example

div { 
    background: rgba(255,255,255,0.5); /* white color with 50% transparency */
}

In IE However, rgba does not works. You need to use filter.

For Example

div {
    background: transparent;
    -ms-filter: "progid: DXImageTransform.Microsoft.gradient(startColorstr=#77ffffff, endColorstr=#77ffffff)"; /* For IE8 */
    filter: progid: DXImageTransform.Microsoft.gradient(startColorstr=#77ffffff, endColorstr=#77ffffff); /* < IE 7 */
    zoom: 1;
}

The color patter in both the start and end color is different than the way in RGBA, it user ARGB Format and all in Hex. Like in above example, following are how the values are distributed

77: alpha (fully transparent: 00, fully opaque: FF) 
ff: Red
ff: Green
ff: Blue

This method will place a transparent background on your division, but if you want the entire div to be tranparent including everything inside, then you can use opacity property

For example

div {
    background: #fff;
    opacity: 0.5; /* This is not support in IE though, use filter if needed in IE *
}

Demo

Question 4

Question by leora

leora

i recently asked this question on how to have a container div width set so i could avoid scrolling for folks with wide monitors. I got a great answer basically to combine min-width with display: block;

I now have one follow up. The accepted answer works great if the browser up front is set to be wide but if at first its not wide and a user stretchs the window, the div container doesn’t change or stretch.

is there anyway i can take this one step further and reset the width of the div when the browser window itself resizes.

Answer

Answer by clairesuzy

clairesuzy

you could use absolute positioning,

#panel {
 position: absolute;
 top: 50px;
 left: 50px;
 right: 50px;
 bottom: 50px;
 background: #eee;
 border: 3px double #000;
 overflow: auto;
 }


<div id="panel"><p>I shrink and grow</p></div>

overflow:auto; sets a scroll bar on the #panel itself if the content requires it.. which may not be desired?

Working Example

Answer

Answer by Starx

Starx

How about estimating the area of screen, your page should cover and writing the width in percentage?

For example,

#wrapper { width: 90%; }

Question 5

Question by tekknolagi

tekknolagi

INSERT INTO homework_MarcWed30-2011 ('Teacher', 'Class', 'Period', 'Assn') 
                              VALUES ('a', 'a', 'a', 'a')

i get the following error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘-2011 (Teacher varchar(30), Class varchar(30), Period varchar(30), Assn varchar(‘ at line 1

what is going on?

on a side note, the create table statement does not work for me:

mysql_query("CREATE TABLE homework_MarcWed30-2011 (Teacher varchar(30), Class varchar(30), Period varchar(30), Assn varchar(400))","mysql_connect('#####', '#####', '#####')") OR die(mysql_error());

Answer

Answer by Positive

Positive

Column names should be out of quotes they can be surrounded by back quote “ but not with single or double quote.

 INSERT INTO `homework_MarcWed30-2011` (`Teacher`, `Class`, `Period`, `Assn`)
 VALUES ('a', 'a', 'a', 'a')

if there is – in table name you can still use by surrounding name in back quotes “.

Answer

Answer by Starx

Starx

Try this query

INSERT INTO `homework_marcwed30-2011` (`Teacher` ,`Class` ,`Period` ,`Assn`) VALUES ('a', 'a', 'a', 'a');

Variation, without field quotes

INSERT INTO `homework_marcwed30-2011` (Teacher ,Class ,Period ,Assn)
VALUES ('a', 'a', 'a', 'a')

Variation, without field defination

INSERT INTO `homework_marcwed30-2011` VALUES ('a', 'a', 'a', 'a')

For the table creation part

mysql_query("CREATE TABLE `homework_MarcWed30-2011` (Teacher varchar(30) NOT NULL, Class varchar(30) NOT NULL, Period varchar(30) NOT NULL, Assn varchar(400) NOT NULL);","mysql_connect('#####', '#####', '#####')") OR die(mysql_error());

Your error is that you didn’t define whether to allow Null or not.

Question 6

Question by Denoteone

Denoteone

I have an image with a link that when clicked I would like the user to be brought to an anchor on the same page and then the cursor to be focused on the input directly below.

<a onclick="document.newsletter.email.focus();" href="#newssection"><img src="images/newsletter_slide.jpg" /></a>

When it is just the onClick it works but does not scroll the page down and when I use the anchor it goes to that section but does not focus.

I switched around the onClick and the href and it didnt help

Answer

Answer by Kyle

Kyle

Try this.

http://jsfiddle.net/HgSjH/3/

<a onclick="document.newsletter.email.focus();return false;" href="#">click me</a>
<form name="newsletter" id="newssection">
  <input id="email" name="email"/>
</form>

Answer

Answer by Starx

Starx

I think a simple

document.getElementById('yourEmailField').focus(); should do the trick.

It will automatically focus to the element, and if needed scroll too.

Question 7

Question by auge

auge

I’m trying to dynamically detect the root directory of my page in order to direct to a specific script.

echo ($_SERVER['DOCUMENT_ROOT']);

It prints /myName/folder/index.php

I’d like to use in a html-file to enter a certain script like this:

<a href="<?php $_SERVER['DOCUMENT_ROOT'].'lib/logout.php'?>">log out</a>

This seems to be in bad syntax, the path is not successfully resolved.

What’s the proper approach to detect the path to logout.php?

The same question in different words:

How can I reliably achieve the path to the root directory (which contains my index.php) from ANY subdirectory? No matter if the html file is in /lib/subfolder or in /anotherDirectory, I want it to have a link directing to /lib/logout.php

On my machine it’s supposed to be http://localhost/myName/folder (which contains index.php and all subdirectories), on someone else’s it might be http://localhost/project

How can I detect the path to application root?

Answer

Answer by Starx

Starx

Try this,

<a href="/lib/logout.php'?>">log out</a>

This jumps to the root directly.

Question 8

Question by Dunhamzzz

Dunhamzzz

I have various jQuery click and submit events on my site, but some of them I only want to activate if the user is logged in (yes I have all required server-side validation), if they are not logged in, I want a jQuery UI dialogue to pop up.

If the user is logged in the page will have a javascript variable set: with var uk = 'randomkey';

What is the best method for this? Off the top of my head some sort of global function which checks for user value and fires the dialogue and returns false? Or is there a neater/optimised way of doing it.

Answer

Answer by Richard Neil Ilagan

Richard Neil Ilagan

Since you say that you’re already performing server-side validation, I’d suggest that you take away all the JS behavior you want for logged-in users, and those for not-logged-in users to two separate JS files, and load the relevant one into the page before your server even flushes the HTML back to the browser.

Answer

Answer by Starx

Starx

It would be better if you would filter the elements while the page is loading, to avoid unauthorised access. Try to avoid complexity as much as possible.

But if you really need to do this, you can send a ajax request to detect if user is logged in (Relying on the client’s browser by setting class name is a bad idea, it can be easily tampered).

Just an example

$.post(
    "apage.php",
    { action: 'checklogged' },
    function(data) {
        //if the response come as `no` and `yes`
        if(data=='no') {
            //dialogbox code
        }
        else {
           var uk = 'randomkey';
        }
    }
);

Question 9

Question by jimmy_in

jimmy_in

<span id="n-email" class="email-btn"><a href="#."></a></span>

On clicking this, a list item with a text field shows

<li id="new" class="select">
    <a>
        <input type="text" id="emails" class="add-email" value="Untitled" onfocus="if(this.value=='Untitled'){this.value=''}" onblur="if(this.value=='')  {this.value='Untitled'}"/>
    </a>
</li>

Suppose I filled something in this input field and press enter.
On pressing enter I want to fire a event which would

Remove the <li> containing the input field.

Insert new <li> in its place, like

<li>
    <a href="#.">
        //here comes the value what we entered in the input field of above li//
    </a>
</li>

Answer

Answer by Starx

Starx

First, you need to hide the #new row, then you need to use keypress event to catch the enter key, finally use the append() method to insert a new element.

Here is a example based on your script

$(".email-btn").click(function() {
    $("#new").show();
});

$("#emails").keypress(function(e)
{
    value = $(this).val();
    code= (e.keyCode ? e.keyCode : e.which);
    if (code == 13) {
        $("#new").remove();
        $("#mylist").append("<li><a>"+value+"</a></li>");
    }

});

Demo

Question 10

Question by Hello_jQuery

Hello_jQuery

Is it possible for jQuery to bind events to elements if the jQuery script block comes before the html tags in the page?

As an example, this does not work:

<script>
    $('a').bind('click', function() {
    alert($(this).attr("innerHTML"));
</script>

<a href="#Hello">Greetings</a>

Yes, I could just put the script after the elements, but hey, maybe I don’t wanna. Just curious if this is the only way.

Answer

Answer by Felix Kling

Felix Kling

Yes, if you put the code in a ready^[docs] event handler (and fix your syntax errors ;)):

$(function() {
    $('a').bind('click', function() {
        alert(this.innerHTML);
        // jQuery way would be: $(this).html()
    });
});

Answer

Answer by Starx

Starx

Another way is to execute the script during $(window).load() event

$(window).load(function() {
    $('a').bind('click', function() {
    alert($(this).attr("innerHTML"));
});

Now the bind will occur once all the document is fully loaded.

Hi! I’m Starx

experienced Software Developer. And this is my blog

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What are the difficulties/issues to consider when allowing ZIP file uploads?

Question by Edward Tanguay

Answer by Starx

How to find whether a json array is empty or not?

Question by hbase_user

Answer by Starx

How to make a div with glassy and semi transparent effect?

Question by selvin

Answer by Starx

resizing div width with browser resize

Question by leora

Answer by clairesuzy

Working Example

Answer by Starx

What is wrong with this MySQL syntax?

Question by tekknolagi

Answer by Positive

Answer by Starx

add an anchor and onClick to a link

Question by Denoteone

Answer by Kyle

Answer by Starx

How to detect the path to the application root?

Question by auge

Answer by Starx

Method for over-riding various jQuery events if a global var is not set

Question by Dunhamzzz

Answer by Richard Neil Ilagan

Answer by Starx

Dynamically generate a <li>?

Question by jimmy_in

Answer by Starx

jQuery script BEFORE HTML elements

Question by Hello_jQuery

Answer by Felix Kling

Answer by Starx

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