Trying to use Backbone's navigate property.
this.navigate("week/" + companyName + "/" + employeeNo + "/" + weekEnd, { trigger: true, replace: false });
The code above is executed once.
It hits this:
routes: {
"week/:companyName/:employeeNo/:weekEnd": "getWeek"
},
And then this function gets hit twice:
getWeek: function (companyName, employeeNo, weekEnd) {
console.log('getWeek:', companyName, employeeNo, weekEnd);
}
It is logged twice in Firefox, only once in IE and Chrome.
What's the issue here? I originally didn't even have trigger set to true, and Firefox ignored that and still triggered the URL.
I had a similar issue recently with Firefox doing two server calls after a Backbone.navigate. In my case it was because we had not encoded the string. Does your company name have any characters which should be encoded?
You could try:
this.navigate("week/" + escape(companyName) + "/" + employeeNo + "/" + weekEnd, { trigger: true, replace: false });
Stepping in as I've run into the same issue and got to the underlying problem here.
As everyone mentioned before, the problem comes from URL encoding. Now as to why the issue only appears in Firefox...
Let's start by summarizing quickly how the routes are called when the hash changes. There are 3 key functions here:
loadUrl: this function is the one that will call your route handler.
navigate: this is the function used to change the route manually. If the trigger flag is set to true, the function will call loadUrl.
checkUrl: this function is set as callback for the onhashchange event on the window object (when it's available of course). It also runs loadUrl on certain conditions.
Now, we're getting to the interesting part.
When you run navigate, Backbone will cache the fragment you navigated to. The hash changing, checkUrl will also be called. This function will then check if the cached hash equals the current one, so as not to execute loadUrl if you called navigate before, because it would mean it has already been called. To make that comparison, checkUrl gets the current hash with the function getFragment, which uses getHash. Here is getHash's code:
getHash: function(window) {
var match = (window || this).location.href.match(/#(.*)$/);
return match ? match[1] : '';
},
And you got your problem. location.href is URI-encoded in firefox, but is not in chrome. So if you navigated to another hash (with or without the trigger flag), in firefox, Backbone will cache the unencoded version of your hash, and then compare it with the encoded version. If your hash contained a should-be-encoded character, the result of the comparison will be negative, and Backbone will execute the route handler it should not execute.
As per the solution, well, folks said it before, your URIs should be encoded.
Question may be old, but for me this was still relevant. Encoding the url wasn't enough in my case. I replaced the GetHash() function in Backbone with:
getHash: function (t) {
var e = (t || this).location.href.match(/#(.*)$/);
return match ? this.decodeFragment(match[1]) : '';
}
Related
I have set up a number of intercepts in the body of my tests. Here they are, pasted from the Cypress log, with the alias added
cy:intercept ➟ // alias: getRecipesSku(971520)
Method: GET
Matcher: "https://wpsite.com/wp-json/wp/v2/posts?tags[]=6287&_fields**"
Mocked Response: [{ ... }]
cy:intercept ➟ // alias: getRecipesSku(971520,971310)
Method: GET
Matcher: "https://wpsite.com/wp-json/wp/v2/posts?tags[]=6287&tags[]=6289&_fields**"
Mocked Response: [{ ... }]
Our application's tests also mocks a number of routes by default, (coming from an apiClient.initialize) including this one below. FWIW, this is defined earlier than those above:
cy:intercept ➟ // alias: getJustcookRecipes
Method: GET
Matcher: "https://wpsite.com/wp-json/**"
Mocked Response: [{ ... }]
My test code sets up those first two intercepts, and ultimately calls the routes. Here is the code, heavily abridged:
it('refreshes the recipes when switching protein tabs', () => {
apiClient.initialize()
/* do lots of other stuff; load up the page, perform other tests, etc */
// call a function that sets up the intercepts. you can see from the cypress output
// that the intercepts are created correctly, so I don't feel I need to include the code here.
interceptJustCook({ skus: [beefCuts[0].id] }, [beefCut1Recipe])
interceptJustCook({ skus: [beefCuts[0].id, beefCuts[1].id] }, twoBeefRecipes)
// [#1] select 1 item;
// calls route associated with intercept "getRecipesSku(971520)"
page.click.checkboxWithSku(beefCuts[0].id)
/* assert against that call */
// [#2] select 2nd item (now 2 items are selected);
// calls route associated with intercept "getRecipesSku(971520, 971310)"
page.click.checkboxWithSku(beefCuts[1].id)
In the Cypress logs, the first call (marked by comment #1) is intercepted correctly:
cy:fetch ➟ (getRecipesSku(971520)) STUBBED
GET https://wpsite.com/wp-json/wp/v2/posts?tags[]=6287&_fields=jetpack_featured_media_url,title.rendered,excerpt.rendered,link,id&per_page=100&page=1&orderby=date
However, the second call (marked by comment #2) is intercepted by the wrong route mocker:
cy:fetch ➟ (getJustCookRecipes) STUBBED
GET https://wpsite.com/wp-json/wp/v2/posts?tags[]=6287&tags[]=6289&_fields=jetpack_featured_media_url,title.rendered,excerpt.rendered,link,id&per_page=100&page=1&orderby=date
You can see for yourself that the URL called at #2 does indeed match the getRecipesSku(971520, 971310) intercept, but it is caught by the getJustcookRecipes intercept. Now, I suppose the URL for that latter intercept would catch my second custom intercept. But it would also, in the same way, catch my first custom intercept, but that first one works.
(update:) I tried commenting out the place in the code where the getJustcookRecipes intercept is created so that it doesn't exist. Now, the call that should hit getRecipesSku(971520,971310) isn't being mocked at all! I checked and the mocked and called urls are a match.
Why is this going wrong and how do I fix it?
Something in the glob pattern for the 2nd intercept #getRecipesSku(971520,971310) is refusing to match.
It's probably not worth while analyzing what exactly (you may not be able to fix it in glob), but switching to a regex will match.
See regex101.com online test
cy.intercept(/wpsite\.com\/wp-json\/wp\/v2\/posts\?tags\[]=6287&tags\[]=6289&_fields/, {})
.as('getRecipesSku(971520,971310)')
The request query string may be badly formed
Looking at the docs for URLSearchParams, the implication is that the query string should be key/value pairs.
But the 2nd request has two identical keys using tags[] as the key.
It looks as if the correct format would be /wp/v2/posts?tags=[6287,6289] since the square brackets don't have a lot of meaning otherwise.
It may be that the server is handling the format tags[]=6287&tags[]=6289, but Cypress is probably not. If you run the following intercept you see the query object has only one tags[] key and it's the last one in the URL.
cy.intercept({
method: 'GET',
pathname: '/wp-json/wp/v2/posts',
},
(req) => {
console.log('url', req.url)
console.log('query', req.query) // Proxy {tags[]: '6289', ...
}
)
#Paolo was definitely on the right track. The WP API we're consuming uses tags[]=1,tags=[2] instead of tags[1,2] so that's correct, but some research into globs showed me that brackets are special. Why the first bracket isn't messing it up but the second one is, I'm not sure and I kind of don't care.
I thought about switching to regex, but instead I was able to escape the offender in the glob without switching to regex and needing to escape aaaallll the slashes in the url:
const interceptRecipes = (
{ category, skus }: RecipeFilterArgs,
recipes: Recipe[]
) => {
let queryString = ''
if (category) queryString = `categories[]=${CATEGORY_MAP[category]}`
if (skus) {
const tagIdMap = SkuToTagIdMap as Record<number, { tagId: number }>
// brackets break the glob pattern, so we need to escape them
queryString = skus.map((sku) => `tags\\[]=${tagIdMap[sku].tagId}`).join('&')
}
const url = `${baseUrl}?${queryString}${otherParams}`
const alias = category ? `get${category}Recipes` : `getRecipesSku(${skus})`
cy.intercept('GET', url, recipes).as(alias)
}
I'm loading some posts though AJAX and my WordPress pagination is using the following function to calculate paging:
get_pagenum_link($paged - 1)
The issue is that the pagination is getting created through AJAX so it's making this link look like: http://localhost:1234/vendor_new/wp-admin/admin-ajax.php
However the actual URL that I'm trying to achieve is for this:
http://localhost:1234/vendor_new/display-vendor-results
Is there a way to use this function with AJAX and still get the correct URL for paging?
I can think of three options for you:
To write your own version of get_pagenum_link() that would allow you to specify the base URL
To overwrite the $_SERVER['REQUEST_URI'] variable while you call get_pagenum_link()
To call the paginate_links() function, return the whole pagination's HTML and then process that with JS to only take the prev/next links.
#1 Custom version of get_pagenum_link()
Pros: you would have to change a small amount of your current code - basically just change the name of the function you're calling and pass an extra argument.
Cons: if the function changes in the future(unlikely, but possible), you'd have to adjust your function as well.
I will only post the relevant code of the custom function - you can assume everything else can be left the way it's in the core version.
function my_get_pagenum_link( $pagenum = 1, $escape = true, $base = null ) {
global $wp_rewrite;
$pagenum = (int) $pagenum;
$request = $base ? remove_query_arg( 'paged', $base ) : remove_query_arg( 'paged' );
So in this case, we have one more argument that allows us to specify a base URL - it would be up to you to either hard-code the URL(not a good idea), or dynamically generate it. Here's how your code that handles the AJAX request would change:
my_get_pagenum_link( $paged - 1, true, 'http://localhost:1234/vendor_new/display-vendor-results' );
And that's about it for this solution.
#2 overwrite the $_SERVER['REQUEST_URI'] variable
Pros: Rather easy to implement, should be future-proof.
Cons: Might have side effects(in theory it shouldn't, but you never know); you might have to edit your JS code.
You can overwrite it with a value that you get on the back-end, or with a value that you pass with your AJAX request(so in your AJAX request, you can have a parameter for instance base that would be something like window.location.pathname + window.location.search). Difference is that in the second case, your JS would work from any page(if in the future you end-up having multiple locations use the same AJAX handler).
I will post the code that overwrites the variable and then restores it.
// Static base - making it dynamic is highly recommended
$base = '/vendor_new/display-vendor-results';
$orig_req_uri = $_SERVER['REQUEST_URI'];
// Overwrite the REQUEST_URI variable
$_SERVER['REQUEST_URI'] = $base;
// Get the pagination link
get_pagenum_link( $paged - 1 );
// Restore the original REQUEST_URI - in case anything else would resort on it
$_SERVER['REQUEST_URI'] = $orig_req_uri;
What happens here is that we simply override the REQUEST_URI variable with our own - this way we fool the add_query_arg function into thinking, that we're on the /vendor_new/display-vendor-results page and not on /wp-admin/admin-ajax.php
#3 Use paginate_links() and manipulate the HTML with JS
Pros: Can't really think of any at the moment.
Cons: You would have to adjust both your PHP and your JavaScript code.
Here is the idea: you use paginate_links() with it's arguments to create all of the pagination links(well - at least four of them - prev/next and first/last). Then you pass all of that HTML as an argument in your response(if you're using JSON - or as part of the response if you're just returning the HTML).
PHP code:
global $wp_rewrite, $wp_query;
// Again - hard coded, you should make it dynamic though
$base = trailingslashit( 'http://localhost:1234/vendor_new/display-vendor-results' ) . "{$wp_rewrite->pagination_base}/%#%/";
$html = '<div class="mypagination">' . paginate_links( array(
'base' => $base,
'format' => '?paged=%#%',
'current' => max( 1, $paged ),
'total' => $wp_query->max_num_pages,
'mid_size' => 0,
'end_size' => 1,
) ) . '</div>';
JS code(it's supposed to be inside of your AJAX success callback):
// the html variable is supposed to hold the AJAX response
// either just the pagination or the whole response
jQuery( html ).find('.mypagination > *:not(.page-numbers.next,.page-numbers.prev)').remove();
What happens here is that we find all elements that are inside the <div class="mypagination">, except the prev/next links and we remove them.
To wrap it up:
The easiest solution is probably #2, but if someone for some reason needs to know that the current page is admin-ajax.php while you are generating the links, then you might have an issue. The chances are that no one would even notice, since it would be your code that is running and any functions that could be attached to filters should also think that they are on the page you need(otherwise they might mess something up).
PS: If it was up to me, I was going to always use the paginate_links() function and display the page numbers on the front-end. I would then use the same function to generate the updated HTML in the AJAX handler.
This is actually hard to answer without specific details of what and how is being called. I bet you want to implement that in some kind of endless-sroll website, right?
Your best bet is to get via AJAX the paginated page itself, and grab the related markup.
Assume you have a post http://www.yourdomain.com/post-1/
I guess you want to grab the pagination of the next page, therefore you need something like this:
$( "#pagination" ).load( "http://www.yourdomain.com/post-1/page/2 #pagination" );
This can easily work with get_next_posts_link() instead of get_pagenum_link().
Now, in order for your AJAX call to be dynamic, you could something like:
$( "#pagination" ).load( $("#pagination a").attr('href') + " #pagination" );
This will grab the next page's link from your current page, and load its pagination markup in place of the old.
It's also doable with get_pagenum_link() however you'd need to change the $("#pagination a").attr('href') selector appropriately, in order to get the next page (since you'd have more than one a elements inside #pagination
In Google Sheets, you can add some scripting functionality. I'm adding something for the onEdit event, but I can't tell if it's working. As far as I can tell, you can't debug a live event from Google Sheets, so you have to do it from the debugger, which is pointless since the event argument passed to my onEdit() function will always be undefined if I run it from the Script Editor.
So, I was trying to use the Logger.log method to log some data whenever the onEdit function gets called, but this too seems like it only works when run from the Script Editor. When I run it from the Script Editor, I can view the logs by going to View->Logs...
I was hoping I'd be able to see the logs from when the event actually gets executed, but I can't figure it out.
How do I debug this stuff?
UPDATE:
As written in this answer,
Stackdriver Logging is the preferred method of logging now.
Use console.log() to log to Stackdriver.
Logger.log will either send you an email (eventually) of errors that have happened in your scripts, or, if you are running things from the Script Editor, you can view the log from the last run function by going to View->Logs (still in script editor). Again, that will only show you anything that was logged from the last function you ran from inside Script Editor.
The script I was trying to get working had to do with spreadsheets - I made a spreadsheet todo-checklist type thing that sorted items by priorities and such.
The only triggers I installed for that script were the onOpen and onEdit triggers. Debugging the onEdit trigger was the hardest one to figure out, because I kept thinking that if I set a breakpoint in my onEdit function, opened the spreadsheet, edited a cell, that my breakpoint would be triggered. This is not the case.
To simulate having edited a cell, I did end up having to do something in the actual spreadsheet though. All I did was make sure the cell that I wanted it to treat as "edited" was selected, then in Script Editor, I would go to Run->onEdit. Then my breakpoint would be hit.
However, I did have to stop using the event argument that gets passed into the onEdit function - you can't simulate that by doing Run->onEdit. Any info I needed from the spreadsheet, like which cell was selected, etc, I had to figure out manually.
Anyways, long answer, but I figured it out eventually.
EDIT:
If you want to see the todo checklist I made, you can check it out here
(yes, I know anybody can edit it - that's the point of sharing it!)
I was hoping it'd let you see the script as well. Since you can't see it there, here it is:
function onOpen() {
setCheckboxes();
};
function setCheckboxes() {
var checklist = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("checklist");
var checklist_data_range = checklist.getDataRange();
var checklist_num_rows = checklist_data_range.getNumRows();
Logger.log("checklist num rows: " + checklist_num_rows);
var coredata = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("core_data");
var coredata_data_range = coredata.getDataRange();
for(var i = 0 ; i < checklist_num_rows-1; i++) {
var split = checklist_data_range.getCell(i+2, 3).getValue().split(" || ");
var item_id = split[split.length - 1];
if(item_id != "") {
item_id = parseInt(item_id);
Logger.log("setting value at ("+(i+2)+",2) to " + coredata_data_range.getCell(item_id+1, 3).getValue());
checklist_data_range.getCell(i+2,2).setValue(coredata_data_range.getCell(item_id+1, 3).getValue());
}
}
}
function onEdit() {
Logger.log("TESTING TESTING ON EDIT");
var active_sheet = SpreadsheetApp.getActiveSheet();
if(active_sheet.getName() == "checklist") {
var active_range = SpreadsheetApp.getActiveSheet().getActiveRange();
Logger.log("active_range: " + active_range);
Logger.log("active range col: " + active_range.getColumn() + "active range row: " + active_range.getRow());
Logger.log("active_range.value: " + active_range.getCell(1, 1).getValue());
Logger.log("active_range. colidx: " + active_range.getColumnIndex());
if(active_range.getCell(1,1).getValue() == "?" || active_range.getCell(1,1).getValue() == "?") {
Logger.log("made it!");
var next_cell = active_sheet.getRange(active_range.getRow(), active_range.getColumn()+1, 1, 1).getCell(1,1);
var val = next_cell.getValue();
Logger.log("val: " + val);
var splits = val.split(" || ");
var item_id = splits[splits.length-1];
Logger.log("item_id: " + item_id);
var core_data = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("core_data");
var sheet_data_range = core_data.getDataRange();
var num_rows = sheet_data_range.getNumRows();
var sheet_values = sheet_data_range.getValues();
Logger.log("num_rows: " + num_rows);
for(var i = 0; i < num_rows; i++) {
Logger.log("sheet_values[" + (i) + "][" + (8) + "] = " + sheet_values[i][8]);
if(sheet_values[i][8] == item_id) {
Logger.log("found it! tyring to set it...");
sheet_data_range.getCell(i+1, 2+1).setValue(active_range.getCell(1,1).getValue());
}
}
}
}
setCheckboxes();
};
As far as I can tell, you can't debug a live event from google docs, so you have to do it from the debugger, which is pointless since the event argument passed to my onEdit() function will always be undefined if I run it from the Script Editor.
True - so define the event argument yourself for debugging. See How can I test a trigger function in GAS?
I was trying to use the Logger.log method to log some data whenever the onEdit function gets called, but this too seems like it only works when run from the Script Editor. When I run it from the Script Editor, I can view the logs by going to View->Logs...
True again, but there is help. Peter Hermann's BetterLog library will redirect all logs to a spreadsheet, enabling logging even from code that is not attached to an instance of the editor / debugger.
If you're coding in a spreadsheet-contained script, for example, you can add just this one line to the top of your script file, and all logs will go to a "Logs" sheet in the spreadsheet. No other code necessary, just use Logger.log() as you usually would:
Logger = BetterLog.useSpreadsheet();
2017 Update:
Stackdriver Logging is now available for Google Apps Script. From the menu bar in the script editor, goto:
View > Stackdriver Logging to view or stream the logs.
console.log() will write DEBUG level messages
Example onEdit() logging:
function onEdit (e) {
var debug_e = {
authMode: e.authMode,
range: e.range.getA1Notation(),
source: e.source.getId(),
user: e.user,
value: e.value,
oldValue: e. oldValue
}
console.log({message: 'onEdit() Event Object', eventObject: debug_e});
}
Then check the logs in the Stackdriver UI labeled onEdit() Event Object to see the output
I've gone through these posts and somehow ended up finding a simple answer, which I'm posting here for those how want short and sweet solutions:
Use console.log("Hello World") in your script.
Go to https://script.google.com/home/my and select your add-on.
Click on the ellipsis menu on Project Details, select Executions.
Click on the header of the latest execution and read the log.
A little hacky, but I created an array called "console", and anytime I wanted to output to console I pushed to the array. Then whenever I wanted to see the actual output, I just returned console instead of whatever I was returning before.
//return 'console' //uncomment to output console
return "actual output";
}
If you have the script editor open you will see the logs under View->Logs. If your script has an onedit trigger, make a change to the spreadsheet which should trigger the function with the script editor opened in a second tab. Then go to the script editor tab and open the log. You will see whatever your function passes to the logger.
Basically as long as the script editor is open, the event will write to the log and show it for you. It will not show if someone else is in the file elsewhere.
I am having the same problem, I found the below on the web somewhere....
Event handlers in Docs are a little tricky though. Because docs can handle multiple simultaneous edits by multiple users, the event handlers are handled server-side. The major issue with this structure is that when an event trigger script fails, it fails on the server. If you want to see the debug info you'll need to setup an explicit trigger under the triggers menu that emails you the debug info when the event fails or else it will fail silently.
It's far from elegant, but while debugging, I often log to the Logger, and then use getLog() to fetch its contents. Then, I either:
save the results to a variable (which can be inspected in the Google Scripts debugger—this works around cases where I can't set a breakpoint in some code, but I can set one in code that gets executed later)
write it to some temporary DOM element
display it in an alert
Essentially, it just becomes a JavaScript output issue.
It grossly lacks the functionality of modern console.log() implementations, but the Logger does still help debug Google Scripts.
Just as a notice. I made a test function for my spreadsheet. I use the variable google throws in the onEdit(e) function (I called it e). Then I made a test function like this:
function test(){
var testRange = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(GetItemInfoSheetName).getRange(2,7)
var testObject = {
range:testRange,
value:"someValue"
}
onEdit(testObject)
SpreadsheetApp.getActiveSpreadsheet().getSheetByName(GetItemInfoSheetName).getRange(2,6).setValue(Logger.getLog())
}
Calling this test function makes all the code run as you had an event in the spreadsheet. I just put in the possision of the cell i edited whitch gave me an unexpected result, setting value as the value i put into the cell.
OBS! for more variables googles gives to the function go here: https://developers.google.com/apps-script/guides/triggers/events#google_sheets_events
Currently you are confined to the container bound nature of using scripts within docs. If you create a new script inside outside of docs then you will be able to export information to a google spreadsheet and use it like a logging tool.
For example in your first code block
function setCheckboxes() {
// Add your spreadsheet data
var errorSheet = SpreadsheetApp.openById('EnterSpreadSheetIDHere').getSheetByName('EnterSheetNameHere');
var cell = errorSheet.getRange('A1').offset(errorSheet.getLastRow(),0);
// existing code
var checklist = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("checklist");
var checklist_data_range = checklist.getDataRange();
var checklist_num_rows = checklist_data_range.getNumRows();
// existing logger
Logger.log("checklist num rows: " + checklist_num_rows);
//We can pass the information to the sheet using cell.setValue()
cell.setValue(new Date() + "Checklist num rows: " + checklist_num_rows);
When I'm working with GAS I have two monitors ( you can use two windows ) set up with one containing the GAS environment and the other containing the SS so I can write information to and log.
The dev console will log errors thrown by the app script, so you can just throw an error to get it logged as a normal console.log. It will stop execution, but it might still be useful for step by step debugging.
throw Error('hello world!');
will show up in the console similarly to console.log('hello world')
For Apps Script projects that are tied to a single Sheet (or doc) — in 2022 — there is no View menu like other answers suggest. Instead you need to look in the Executions menu on the left sidebar to see the executions of your onSelectionChange function (or any other function), from there you can click REFRESH until your console.log messages appear.
just debug your spreadsheet code like this:
...
throw whatAmI;
...
shows like this:
I have a url containing a hash e.g http://www.acme.com/home.xsp#key=1234
When the url above loads in the browser I need to call a serverside javascript based on the value in the hash.
I have found a few ways of retriving the hash client side like this
var key = getHashUrlVars()["key"];
so I have the key available in my client side script in the onclientload event.
So in the same onClientLoad event I now need to call my server side javascript method so I have tried the following
'#{javascript:doStuff(key)}'
'#{javascript:doStuff(' + key + ')}'
..and a few other ways. but I can't get it to work.
maybe there is an XSP command I can use instead?
any ideas how to solve this?
You could do a XSP.partialRefreshPost in CSJS and use parameters to send your data to the server:
var p = { "key": getHashUrlVars()["key"] }
XSP.partialRefreshPost( '#{id:_element_to_refresh_}', {params: p} );
To access the parameters in SSJS just try this:
doStuff( param.key )
You could use an empty div-element as a target execute the SSJS code. Or you can use the executeOnServer - method: http://xpages.info/XPagesHome.nsf/Entry.xsp?documentId=88065536729EA065852578CB0066ADEC
Hope this helps
Sven
I have read a number of posts about this but none with any solid answer. Here is my code:
// button creation
onew = document.createElement('input');
onew.setAttribute("type", "button");
onew.setAttribute("value", "hosts");
onew.onclick = function(){fnDisplay_Computers("'" + alines[i] + "'"); }; // ie
onew.setAttribute("onclick", "fnDisplay_Computers('" + alines[i] + "')"); // mozilla
odiv.appendChild(onew);
Now, the setAttribute() method (with the mozilla comment) works fine in mozilla but only if it comes AFTER the line above it. So in other words it seems to just default to whichever gets set last. The .onclick method (with the ie comment) does not work in either case, am I using it incorrectly?
Either way I can't find a way to make this work at all in IE, let alone in both. I did change the function call when using the .onclick method and it worked fine using just a simple call to an alert function which is why I believe my syntax is incorrect.
Long story short, I can't get the onclick parameter to work consistently between IE/Mozilla.
-- Nicholas
onew.setAttribute("type", "button");
Never use setAttribute on HTML documents. IE gets it badly wrong in many cases, and the DOM-HTML properties are shorter, faster and easier to read:
onew.type= 'button';
onew.onclick = function(){fnDisplay_Computers("'" + alines[i] + "'"); }; // ie
What is ‘alines’? Why are you converting it to a string and surrounding it with single quotes? It looks like you are trying to do something heinous involving evaluating code in a string (which is what you're doing below in the ‘onew.setAttribute’ version). Evaluating JavaScript code in strings is almost always the Wrong Thing; avoid it like the plague. In the above case, IE should do the same as Firefox: it shouldn't work.
If ‘alines[i]’ is a string, I guess what you're trying to do is make it remember that string by constructing a code string that will evaluate in JavaScript to the original string. But:
"'" + alines[i] + "'"
is insufficient. What happens if ‘alines[i]’ has an apostrophe in, or a backslash?
'O'Reilly'
you've got a syntax error and possible security hole. Now, you could do something laborious and annoying like:
"'" + alines[i].split('\\').join('\\\\').split("'").join("\\'") + "'"
to try to escape the string, but it's ugly and won't work for other datatypes. You could even ask JavaScript to do it for you:
uneval(alines[i])
But not all objects can even be converted to evaluatable JavaScript source strings; basically the entire approach is doomed to failure.
The normal thing to do if you just want to have the onclick callback call a function with a parameter is to write the code in the straightforward way:
onew.onclick= function() {
fnDisplay_Computers(alines[i]);
};
Generally this will work and is what you want. There is, however, a slight wrinkle which you may have hit here, which could be what is confusing you into considering the wacky approach with the strings.
Namely, if ‘i’ in this case is the variable of an enclosing ‘for’ loop, the reference to ‘alines[i]’ won't do what you think it does. The ‘i’ will be accessed by the callback function when the click happens — which is after the loop has finished. At this point the ‘i’ variable will be left with whatever value it had at the end of the loop, so ‘alines[i]’ will always be the last element of ‘alines’, regardless of which ‘onew’ was clicked.
(See eg. How to fix closure problem in ActionScript 3 (AS3) for some discussion of this. It's one of the biggest causes of confusion with closures in both JavaScript and Python, and should really be fixed at a language level some day.)
You can get around the loop problem by encapsulating the closure in its own function, like this:
function callbackWithArgs(f, args) {
return function() { f.apply(window, args); }
}
// ...
onew.onclick= callbackWithArgs(fnDisplay_Computers, [alines[i]]);
And in a later version of JavaScript, you'll be able to say simply:
onew.onclick= fnDisplay_Computers.bind(window, alines[i]);
If you would like to be able to use ‘Function.bind()’ in browsers today, you can get an implementation from the Prototype framework, or just use:
if (!('bind' in Function.prototype)) {
Function.prototype.bind= function(owner) {
var that= this;
var args= Array.prototype.slice.call(arguments, 1);
return function() {
return that.apply(owner,
args.length===0? arguments : arguments.length===0? args :
args.concat(Array.prototype.slice.call(arguments, 0))
);
};
};
}
I usually use something like:
onew.onclick = new Function("fnDisplay_Computers('" + alines[i] + "')");
this should work both in IE e Firefox.
Use the addEventListener() function with "click" for the type argument for Mozilla-based browsers, and attachEvent() function with "onclick" as the sEvent argument for IE; I find it best to use a try/catch statement, for example:
try {
onew.attachEvent("onclick", //For IE
function(){fnDisplay_Computers("'" + alines[i] + "'"); });
}
catch(e) {
onew.addEventListener("click", //For Mozilla-based browsers
function(){fnDisplay_Computers("'" + alines[i] + "'"); },
false);
}
I think #3 protesteth too much. In a lot of situations I'm building a table dynamically and need to pass parameters to the callback function. It isn't a typesafe issue since my variable parm is an integer index to the table row in question. Here's code with both a variable and fixed parameter that seems to be cross-browser compliant:
for (i = 0; i < arrTableData.length; i++) {
eleTR = objTable.insertRow(i + 1);
cell = eleTR.insertCell(0);
cell.width = "21";
var myElement = document.createElement('img');
myElement.setAttribute('src', 'images/button_down.gif');
myElement.setAttribute('alt', 'Move item down');
myElement.onclick = new Function('moveItem(' + i + ',0)');
cell.appendChild(myElement);
}