JavaScript - Converting Anonymous Function To Function Loses Object
Hi All, I'm trying to convert an anonymous function to a real function (nesting is getting out of hand), however the msg object becomes undefined after conversion. Here is the converted anonymous function which fails: https://gist.github.com/2587613 and here is the original anonymous function which works: https://gist.github.com/2587667
Any help would be greatly appriciated Similar TutorialsWhat I want to do is have a two-dimension array where some of the elements point to the value in another element. I have done this successfully in PHP using referfences (=&) and now I want to do it in JavaScript. My JS skills are limited but I found this post explaining how it can be done - http://stackoverflow.com/a/1687183 Here's the code from that - Code: Function.prototype.toString = function() { return this(); } var x = 1; var y = function() { return x } x++; alert(y); // prints 2 It looks like it will do what I need to do. However, I want to use a two-dimension array, and if I try this it doesn't work - Code: for (var a = 2; a <= 5; a++) for (var b = 1; b < a; b++) matrix[a][b] = function() { return (matrix[b][a]) }; matrix is the two-dimension array which is alreay set up with some values. The two for loops are structured to fill in the rest of the values as references to existing values (it's a 5 x 5 array). The problem is coming from function() { return (matrix[b][a]) } because instead of the values for a and b being used in the creation of the anonymous function the actual variable names are used instead. Then later when I attempt to read one of the values setup by this it is "undefined" because the anonymous function is tries to return matrix[a][b] rather than matrix[4][2]. Can anyone help? Thanks! Hello, I'm hoping someone can help me with this. I have 3 pages that I need to put into my framework, they are products, shopping cart and billing. At the moment they work perfectly fine. Here is a live example - http://www.cems.uwe.ac.uk/~r4-george...g/products.php Now, I have a framework for a whole website that I need to put these pages into. (http://www.cems.uwe.ac.uk/~r4-george/wp4/index.php) The index uses a switch statement to go between pages. Here is the index.php PHP Code: <?php # index.php /* * This is the main page. * This page includes the configuration file, * the templates, and any content-specific modules. */ // Require the configuration file before any PHP code: require_once ('./modules/config.inc.php'); // Validate what page to show: if (isset($_GET['p'])) { $p = $_GET['p']; } elseif (isset($_POST['p'])) { // Forms $p = $_POST['p']; } else { $p = NULL; } // Determine what page to display: switch ($p) { case 'about': $page = 'about.inc.php'; $page_title = 'About This Site Again'; break; case 'products': $page = 'products.inc.php'; $page_title = 'Products on this site'; break; case 'this': $page = 'this.inc.php'; $page_title = 'This is Another Page.'; break; case 'that': $page = 'that.inc.php'; $page_title = 'That is Also a Page.'; break; case 'contact': $page = 'contact.inc.php'; $page_title = 'Contact Us'; break; case 'search': $page = 'search.inc.php'; $page_title = 'Search Results'; break; // Default is to include the main page. default: $page = 'main.inc.php'; $page_title = 'Site Home Page'; break; } // End of main switch. // Make sure the file exists: if (!file_exists('./modules/' . $page)) { $page = 'main.inc.php'; $page_title = 'Site Home Page'; } // Include the header file: include_once ('./includes/header.inc'); echo "<div id=\"content\">"; // Include the content-specific module: // $page is determined from the above switch. include ('./modules/' . $page); // Include the footer file to complete the template: include_once ('./includes/footer.inc'); ?> It uses the .inc.php files located in the modules folder to switch between pages. Here is my products.inc.php - PHP Code: <? include("includes/db.php"); include("includes/functions.php"); if($_REQUEST['command']=='add' && $_REQUEST['productid']>0){ $pid=$_REQUEST['productid']; addtocart($pid,1); header("location:shoppingcart.php"); exit(); } ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Products</title> <script language="javascript"> function addtocart(pid){ document.form1.productid.value=pid; document.form1.command.value='add'; document.form1.submit(); } </script> </head> <body> <form name="form1"> <input type="hidden" name="productid" /> <input type="hidden" name="command" /> </form> <div align="center"> <h1 align="center">Products</h1> <table border="0" cellpadding="2px" width="600px"> <? $result=mysql_query("select * from products"); while($row=mysql_fetch_array($result)){ ?> <tr> <td><img src="<?=$row['picture']?>" /></td> <td> <b><?=$row['name']?></b><br /> <?=$row['description']?><br /> Price:<big style="color:green"> £<?=$row['price']?></big><br /><br /> <input type="button" value="Add to Cart" onclick="addtocart(<?=$row['serial']?>)" /> </td> </tr> <tr><td colspan="2"><hr size="1" /></td> <? } ?> </table> </div> </body> </html> This is EXACTLY the same code as the working example. The products get listed correctly but the problem I have is the 'Add to Cart' button fails to work. Live example - http://www.cems.uwe.ac.uk/~r4-george...php?p=products Everything is in the right directory. When I inspect the 'Add to Cart' button in chrome I get the following - Quote: Uncaught TypeError: Cannot set property 'value' of undefined addtocart index.php:51 (anonymous function)index.php:83 onclick Any help is really appreciated, I'm struggling to see what I have done wrong. I don't know whether it's a Javascript problem. If you need any of the code from other pages I can post it too. Thanks in advance. I've been going through this great tutorial on how to implement a type-ahead feature on a text field and there's something which hopefully you guys can explain. On the third page there is this function. Code: AutoSuggestControl.prototype.init = function () { var oThis = this; this.textbox.onkeyup = function (oEvent) { if (!oEvent) { oEvent = window.event; } oThis.handleKeyUp(oEvent); }; }; What I don't understand is this line: this.textbox.onkeyup = function (oEvent) { I know about anonymous functions, but I don't know where the value for the parameter oEvent is going to come from. Can someone explain this? Thanks! :) Hello! I'm working with nested functions and trying to pass a 'this' value to an anonymous being used in an assignment for an event listener. Here's the basics of my code: Code: <div id='abc'></div> <script type='text/javascript'> var abc = function () { this.myFunction = function() { var myObj myObj = document.createElement("input"); myObj.setAttribute("type", "button"); myObj.setAttribute("value", "Click Me"); myObj.addEventListener("click", function () { this.doDing(); }, false); document.getElementById('abc').appendChild(myObj); } this.doDing = function () { alert('ding'); } } var myInstance = new abc(); myInstance.myFunction(); </script> So, this should plop a button inside our DIV and when clicked I'd like it to run the alert-ding; unfortunately it seems to want to run the function as defined under the buttons object which doesn't work out too well. Any suggestions? Thanks! Hi everyone, I am pretty new at javascript OOP. I have a javascript file that has plenty of javascript functions, variables, arrays, etc. I need to convert this into an object. Here is an example: Code: var myvar1 = ''; var myvar2 = new array(); var myvar3 = new array(); var myvar4; var myvar5 = 60; var myvar6 = ''; function myfunc1(){ myvar1 = 'hello'; return myvar1; } function myfunc2(somenum=0){ myvar5 = somenum; //calling myfunc1() from within this function. //do something in here } function myfunc3(){ //calling myfunc1() from within this function. for(i=0;i<somelength;i++){ myvar2 = myvar3[i]; (something to put into the array) } } 1. I need to create an object and put ALL the varibles (myvar1 - myvar5) in that object. 2. Then the first two functions "myfunc1 and myfunc2" inside the same object. 2. And the function myfunc3 needs to sit OUTSIDE my object as a regular javascript function. It calls on myfunc1 (which is inside the object) and also inserts data into myvar2 (which is classified inside the object) and myvar3 (which is classified inside the object as well). This is what i came up with, but it's not going well: Code: var myobj1 = function(){ this.myvar1 = ''; this.myvar2 = new array(); this.myvar3 = new array(); this.myvar4; this.myvar5 = 60; this.myvar6 = ''; var myfunc1 = function(){ this.myvar1 = 'hello'; return this.myvar1; } var myfunc2 = function(somenum=0;){ this.myvar5 = somenum; //calling this.myfunc1() from within this function. //do something in here } } function myfunc3(){ //calling mynewobj.myfunc1() from within this function. for(i=0;i<somelength;i++){ mynewobj.myvar2 = mynewobj.myvar3[i]; (something to put into the array) } } var mynewobj = myobj1; HELP.....!!!! i really want to get into object oriented world, so thanks in advance. Hey all, I am confused about the true difference between the two below examples. Code: first example: // Demonstrating a problem with closures and loops var myArray = [“Apple”, “Car”, “Tree”, “Castle”]; var closureArray = new Array(); // Loop through myArray and create a closure for each that outputs that item for (var i = 0; i < myArray.length; i++) { var theItem = myArray[i]; closureArray[i] = function() { document.write(theItem + “ < br / > ”); } } // Loop through the closures and execute each one. for (var i = 0; i < closureArray.length; i++) { closureArray[i](); } Here we iterate through the length of myArray, assigning the current index of myArray to theItem variable. We declare closureArray 4 times as an anonymous function. The anonymous function in turn declares the predefined write() function, which is passed parameters. Since write() is in closureArray() a closure is created??? During each iteration, theItem is reassigned its value. The four closures reference this value. Since they reference this same value and since this value is reassigned ultimately to the value of the fourth index position, tHe time we execute closureArray later on, all four closures output the same string. This is because all four closures are within the same scope "the same environment" and therefore are referencing the same local variable, which has changed. I have a couple of problems with this example: 1) I thought a closure is a function that is returned - the inner function is not returned above. 2) theItem is not even a local variable of the parent function (closureArray) - I thought in order for a closure to work, the inner function only accesses the local variables of the outer function, but in this case the local variable is defined OUTSIDE of the parent function. 3) The guy says the "the four closures are sharing the same environment." The thing is even in the second example, they are sharing the same environment. Second example: Code: // A correct use of closures within loops var myArray = [“Apple”, “Car”, “Tree”, “Castle”]; var closureArray = new Array(); function writeItem(word) { return function() { document.write(word + “ < br / > ”); } } // Loop through myArray and create a closure for each that outputs that item for (var i = 0; i < myArray.length; i++) { var theItem = myArray[i]; closureArray[i] = writeItem(theItem); } // Loop through the closures and execute each one. for (var i = 0; i < closureArray.length; i++) { closureArray[i](); } Here we iterate over the length of myArray (4 times), assigning the index of myArray to theItem variable. We also return a function reference to the closureArray during each iteration (closureArray[i]), where i is index number so we assign 4 functon references. So when we iterate through myArray, we immediatelly call the writeItem() fucntion passing an argument of theItem at its current value. This returns a child anonymous function and when that child function is called, it will execute a block that calls the predefined write() method. We assign that returned anonymous function to the variable closureArray. Hence, closureArray holds a reference to that anonymous function. So closureArray during each iteration holds a reference to the anonymous function and we later call closureArray, which in turn calls the anonymous function, therefore calling the predefined write() function to output the local variable of the parent function. This outputs each distinct index of myArray. QUESTION: This is because since we created the closure, when we call writeItem, passing theItem argument, since theItem is a local variable of the parent function of the closure, it is never destroyed when we later call closureArray (the reference to the child anonymous function)? Yet weren't we using a closure in the first example as well? So whey wasn't those variables preserved? I don't think it has anything to do with assigning a returned anonymous function to closureArray. Even though an anonymous function creates a new memory position in the javascript engine, therefore not overwriting the other function references we create during the iteration, it's still referring to a local variable declared outside the reference. So if it's about the closure retaining value of parent's local variable even after exiting the parent function allowing for the current indexes to be preserved, then why did the closure in the first example fail to retain each index? Thanks for response Hi I need help with a function inside an object that is inserted into a function argument which is then used in a string that is returned. For a quick example which may help you understand. Code: function fn(o) { var text = '<a onclick="function(){'+o.func+'};">Click me!</a>'; document.write(text); } fn({ func: function() {alert('clicked');} }); The above code should display a link on the page saying 'Click me!' and once you click it, an alert box should pop up but it doesn't seem to be working, can anyone help please, thank you. EDIT***** I'm nearly done with my script. I just lack one thing! I have 4 prompts asking a user for information. Basically all I want to do is.. If lastname, and first name are BOTH entered, seperate them with a comment like so : lastname,firstname but leave the comma out, if only one of the names are entered. How could I do this? <script type="text/javascript"> last=name=area=num=''; function info ( ) { last = prompt("Please enter your last name",''); name = prompt("Please enter your first name",''); area = prompt("Please enter your area code",''); num = prompt("Please enter your phone number",''); }; function Person (info) { this.name = name this.last = last this.area = area this.num = num } </script> <title></title> </head> <body> <script type="text/javascript"> info ( ); teacher = new Person(); tempString=''; document.writeln ( last ); document.writeln ( name) ; if(area==''||num==''){tempString='';} else{tempString = teacher.area +''+ teacher.num} document.writeln ( tempString); </script> I am tasked with making a function that can accept many different items and return whether or not they exist. Currently I am struggling on seeing if an object that holds all the methods for a button exists. I thought I could pass in the string name of the object then do a $('buttonObject').length >0 in the 'Exists' method to see if it was created yet. However this will never return true, and I cannot pass in the object into my exists function without it being created yet (throws error). So something like Exists(buttonObject) won't work, I'll have to pass in the string name of it (Exists('buttonObject')) or something else (I'm new to JS). So how do I go about testing whether or not it exists if I cannot pass in buttonObject, without quotes? Hello was following a tutorial online from bucky. and created a new example with different variables and such. My code in my eyes looks absolutely fine but however it does not display can anyone spot the problem? [code] <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Untitled Document</title> <script type="text/javascript"> function cigerettes (brand, tar, price) { this.brand=brand; this.tar=tar; this.price=price; this.ReducedCost = discount; } function discount() { var reduction = 20; var finalCost = this.price - reduction; return finalCost; } var packet1 = new cigerettes("Mayfair", "2.0 mg", 399); var packet2 = new cigerettes("Sovereign", "3.4 mg", 425); </script> </head> <body> <script type="text/javascript"> document.write(packet1.brand() + " they contain " + packet1.tar() + "of tar " + "the packet cost me " + packet1.price() + ". With discount I got them for: " + packet1.ReducedCost()); </script> </body> </html> [code] Hello, I have a code: Code: var device = function(pos_X,pos_Y,serial){ this.pos_x = pos_X; this.pos_y = pos_Y; this.serial_number = serial; this.click = function(){ $("#Control").html("Menu"); }; this.draw = function() { $("#MainArena").append("<div style='position: absolute; top: "+this.pos_y+"px; left: "+this.pos_x+"px;' onclick='"+alert('click')+";'>device</div>"); }; this.move = function(newX, newY) { this.pos_x = newX; this.pos_y = newY; }; [...] <body> <div id="MainArena"></div><div id="Control"></div> devices = new device(100,100,1); devices.draw(); </body> The main problem is in "onclick" in <div> element. This script generates: <div id="1" style="position: absolute; top: 100px; left:100px;" onclick="undefined;">device</div> Hello, I am attempting to implement a javascript joystick plugin. The project has a google code page located at: http://code.google.com/p/javascript-joystick/ After installing the plugin, the javascript works flawlessly in IE and FF, however chrome has some issues with executing it. A hosted version of what I am having trouble with can be found at http://www.jimmyblaze.net/joytest/simple.html The issue seems to be with a snippet of code from the main script that attempts to create an object and embed it on the page. The trouble area can be found he Code: try { ctrlFF.type = "application/x-vnd.numfum-joystick"; ctrlFF.width = 0; ctrlFF.height = 0; /* * Before accessing the plug-in's script interface it needs to be * added to the page. If the 'setDevice' call fails, the plug-in * is assumed to either not be installed or not working in this * browser, in which case it is removed in the catch. */ document.body.appendChild(ctrlFF, document.body); if (ctrlFF.setDevice(0) != null) { /* * As with the code for IE, any non-null value is a * success. */ return ctrlFF; } Chrome doesn't seem to support the .setDevice function, as when running the chrome developer tools inspect element tool, I can see it throw an exception at that line, and prompts the user to update java, because it thinks it is out of date. Has anyone run into this issue with chrome and know of a possible fix? Thanks a lot for your time, Legomaniac Hi, I am facing a problem in passing replace() function as an argument in user defined java function, can any one help me how to resolve it? intention is to pass a file path to my user defined function, but before passing the path i want to replace the character '\' to '\\' I am posting my javascript function he <a href="#" onclick="OpenDocPreview('<%# Eval("PATH")%>'.replace(/\\/g,"\\\\"), '<%# Eval("Filename")%>')"><%# Eval("DocTitle") %></a> function OpenDocPreview(url, docname) { alert('message from search base : ' + url + ' ' + docname); } thank you, I was working on a tutorial for some ajax uploading stuff and I ran across a new function syntax I don't recognize. I am not a Javascript pro, but I am not a newbie either. here is the code I am working on: Code: function handleFileSelect(e){ var files = e.target.files; var output = []; for(var i=0,f;f=files[i];i++){ if(f.type.match('image.*')){ var reader = new FileReader(); reader.onload = (function(theFile){ return function(e){ var span = document.createElement('span'); span.innerHTML = ['<img class="thumb" src="',e.target.result,'" title="',theFile.nbame,'" />'].join(''); document.getElementById('list').insertBefore(span,null); }; })(f); reader.readAsDataURL(f); } } document.getElementById('list').innerHTML = '<ul>'+output.join('')+'</ul>'; } document.getElementById('files').addEventListener('change',handleFileSelect,false); To be a little more clear, the code in question is that is the very middle. The syntax I don't understand is: Code: class.event = (function(arguments){ //stuff you put in a function... })(more Arguments?); I tried to customize a simple one to learn for myself and I wrote this: Code: var a = 'A'; var b = 'B'; test = (function(t){ alert(t); alert(b); })(b); test(a); The browser would alert 'B' and that's it. The console would tell me that 'test is not a function.' OK, so I am confused. The topmost code works. What I am wondering is what the syntax is called for creating a function (or event listener?) that way, and how it works. Although if I new what it was called I could just google how it works. <p> <script type="text/javascript">// <![CDATA[ var metrics = { "mm" : 1, "cm" : 10, "m" : 1000, "inch" : 25.4, "foot" : 304.8 }; function convert(num, dec){ var val = document.getElementById("fromVal").value; if(isNaN(val)){ return } function roundNumber(num, dec) { var result = Math.round( Math.round( num * Math.pow( 10, dec + 1 ) ) / Math.pow( 10, 1 ) ) / Math.pow(10,dec); return result; } document.getElementById("toVal").value = val * metrics[document.getElementById("fromSystem").value]/ metrics[document.getElementById("toSystem").value]; } var interval = null; function watchChanges(){ interval == null ? setInterval("convert()", 500) : clearInterval(interval); } // ]]></script> </p> <table> <tbody> <tr> <td><input id="fromVal" style="width: 100px;" onfocus="watchChanges()" onblur="watchChanges()" type="text" /><select id="fromSystem" onchange="convert()"> <option value="mm">millimeters</option> <option selected="selected" value="cm">centimeters</option> <option value="m">meters</option> <option value="foot">feet</option> <option value="inch">inches</option> </select></td> </tr> <tr> <td colspan="1" align="center">=</td> </tr> <tr> <td><input id="toVal" style="width: 100px;" type="text" disabled="disabled" /><select id="toSystem" onchange="convert()"> <option value="mm">millimeters</option> <option value="cm">centimeters</option> <option value="m">meters</option> <option selected="selected" value="foot">feet</option> <option value="inch">inches</option> </select></td> Hi! I'm trying to toggle a class and one works and the other does not and I don't know why. I'm just getting my feet wet with jquery and javascript and I figured this was a pretty easy task to take on! Maybe. Link to the page: Franklin Township Soccer Club - Change Field Status My sad, sorry attempt =| Code: $( "li.open" ).click(function() { $( this ).toggleClass( "closed" ); }); $( "li.closed" ).click(function() { $( this ).toggleClass( "open" ); }); The first function works with open, so I figured I'd just use opposite on closed! Ha! I don't think so! In the end within those function there is an element in a form on that page it's hidden. I'd like to change the value from a 0 to 1 for vice versa. That' will be my next step. If you could give me a little nudge in the right direction I'd appreciate it! But first understanding why one works and the other does not, that is the primary mission! I do appreciate any help given! Dave i keep getting error Call to undefined function codeandurl() below is my code PHP Code: <?php $value= strip_tags(get_field('link',$post)); $resultid=get_field('resultid',$post); codeandurl($resultid,$value); ?> <div id="result"></div> <script type="text/javascript"> function codeandurl(resultid,url){ $( "#result" ).text(resultid); $( "#result" ).dialog({ modal: true, buttons: { Ok: function() { $( this ).dialog( "close" ); } } }); window.open(url); return false; } </script> I found this script, and it works great: Code: <script type="text/javascript"> function disable(element) { var input = document.getElementById(element).getElementsByTagName("input"); for(var i = 0; i < input.length; i++) { input[i].setAttribute("disabled","true"); } } </script> I tried to make the inverse by simply reversing the setAttribute() like so: Code: <script type="text/javascript"> function enable(element) { var input = document.getElementById(element).getElementsByTagName("input"); for(var i = 0; i < input.length; i++) { input[i].setAttribute("disabled","false"); } } </script> But that didn't do it. Can someone show me why, and how to fix it? Here's the sample form which I'm trying to test it on: Code: <form> <input type="radio" name="test" onclick="disable('D1')" /> disable<br/> <input type="radio" name="test" onclick="enable('D1')" /> enable<br/> <fieldset id="D1"> <input class="" type="text" value="test value1" /><input class="" type="text" value="test value2" /><br/> <input class="" type="text" value="test value3" /><input class="" type="text" value="test value4" /><br/> <input class="" type="text" value="test value5" /><input class="" type="text" value="test value6" /><br/> </fieldset> </form> Edit: The ultimate goal which I'm working toward now (step by step =) is to have a form more like: Code: <form> <input type="radio" name="test" onclick="disable('D1')" /> <fieldset id="D1"> <input class="" type="text" value="test value1" /><input class="" type="text" value="test value2" /> </fieldset> <input type="radio" name="test" onclick="disable('D2')" /> <fieldset id="D2"> <input class="" type="text" value="test value3" /><input class="" type="text" value="test value4" /> </fieldset> <input type="radio" name="test" onclick="disable('D3')" /> <fieldset id="D3"> <input class="" type="text" value="test value5" /><input class="" type="text" value="test value6" /> </fieldset> </form> And have the fieldsets enable and disable according the selection of the radio buttons. Also, the fieldsets (and their ID's) will be dynamically generated via PHP Thanks-a-bunch, ~ Mo I made a mouseover event of a caption on a picture, when I hover the opacity of the background color of the hover and the text goes down. What I want is that when I hover over the image which the caption is floating on, the onmouseover event gets activite. For an imaginary example: Code: function unhighlight(x) { x.style.backgroundColor="transparent" } Function ActivationFuction() { activate.function="unhighlight" } thanks Thank you in advance if someone can help. I have been banging my head against the wall for hours now. Here is the code: Code: for (var i = 0; i < BS_crm['activityTypes'].length; i++) { var clickFunc = function(){ activityList.showForm( -1, {blockType:[""+BS_crm['activityTypes'][i]['id'], "0"]} ); }; var type = { value: BS_crm['activityTypes'][i]['id'], label: "Add New "+BS_crm['activityTypes'][i]['label'], css: BS_crm['activityTypes'][i]['css']+"_16", onClick: clickFunc }; previewLinks.items.push( type ); } Now, basically what I am doing here is running through one array to create an array of objects, that will be used to create links that will use whatever onClick function I pass it. The problem is that on the second line I need the BS_crm['activityTypes'][i]['id'] to be a value, not a reference. If that line was simply changed to: Code: var clickFunc = function(){ activityList.showForm( -1, {blockType:["3", "0"]} ); }; then everything would work as I need. How can I make this happen? I would really appreciate any help. Thank you again in advance. |