Develop Reference

How can I edit html inside an iframe using javascript

I am working on automating a process within my business, part of which is sending an email through SalesForce. We don't have access to the SF API and the email has to be sent through salesforce in order to keep the communication searchable for the coworkers.
I need to use a template which can be selected in SalesForce, however this function does not work in IE (which our RPA solution uses) so I need to build this email from scratch.
I see two options for this:
Use the HTML to recreate the format with the right variables. This entails inserting/injecting/manipulating HTML.
Copy the format into memory/the clipboard, edit it programatically and paste it into the SF interface
This question will be about option 1. I will post an additional question with regards to the second option separately and edit this question to include that link. EDIT: Here is the link to the other question!
Now on to the question:
We use the Blue Prism RPA software suite. It has a possibility to insert javascript fragments into a website and subsequently invoke them. I was hoping that I could create a javascript fragment that recreates the template, insert it and then invoke it. I have been working on this for the past week and have hardly gotten any further.
I now am able to add basic text into the required field, but have found that to be able to use the template structure I need to use a different, HTML based, field. This field I find lives inside an iframe.
I have had zero experience with javascript prior to this week (luckily it seems similar to c# in which I do have experience) and now this iframe has me stumped. Apparently when you use Selenium or similar you can switch the driver to the new iframe but I don't have that option, it needs to be done through surface automation. Within javascript as well as the console I can not get it to target the separate document within the iframe. Apparently the iframe contents are not incorporated in that way in the bigger webpage.
So my question is this: How can I "switch focus" to the iframe using javascript? How can I then edit the iframe contents through javascript? Any help, tips etc. would be highly appreciated!

If you go to developer tools in the browser (F12 or right-click inspect) you can use the inpsect tool to get the path you are looking for. an iframe is just another window inside the window and once you have the 'base path' you can then extend further into the window from the iframe base path.
You can access frames one of two ways I know of;
document.getElementById('the frame you are looking for goes here').contentWindow.targetFunction();
and/or
window.frames[0].otherfunctions
where 0 is the Nth order of frame on the window in case there are others.
once you find that path you can interact with sub-elements on that iframe by getting the path to it from within the iframe.
some things to watch out for. frames not loading yet so make sure the frame you want is loaded and no other frame is moving it around the screen at run time. Also make sure the child frame is in the same domain, I think calling javascript has issues when going cross-domain i.e. it doesn't work (stand to be corrected there though maybe it depends on group settings)
Supply some code or the layout of the page and could give you a code example but top of my head the format will look like this
var doc = window.frames[0]
var thing = getElementById(doc.getElementByPath('maybePath')
'perform some set operations like set innerhtml to thing you desire

Why does Gmail go bonkers once Modernizr is dynamically loaded in it?

Entering this into the Chrome or Safari inspector console, inside Gmail:
function load(url,cb){var x=document.body.appendChild(document.createElement('script'));x.src=url;x.onload=function(){console.log("Dynamically loaded "+url);if(cb){cb();}};if(!cb){x.setAttribute('async','')}}
load("https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js",function(){alert("Modernizr loaded");});
Causes the layout of much of the text to go crazy.
Can this be explained? I'd like for my tool (which involves running a bookmarklet which dynamically loads Modernizr) to work on Gmail.

Modernizer adds a lot of classes to the <html> tag, and one of those classes is js. I couldn't find anything in the documentation that describes what that represents, although I suspect it just represents JavaScript support. Google has minified their classes, so they are all short two letter items (probably generated). One of them happens to be js as well, which is causing a lot of text to get centered.
In fact, to un-hose it, just remove the js class from the <html> tag after dynamically loading your script and it fixes itself.
Here's a fixed version:
function load(url,cb){var x=document.body.appendChild(document.createElement('script'));x.src=url;x.onload=function(){console.log("Dynamically loaded "+url);if(cb){cb();}};if(!cb){x.setAttribute('async','')}}
load("https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js",function(){var htmlElement = document.getElementsByTagName("html")[0]; htmlElement.className = htmlElement.className.replace
( /(?:^|\s)js(?!\S)/g , '' ); alert("Modernizr loaded");});

How to use page-mod to modify element loaded by JavaScript

I'm creating firefox addon to add onclick event to the specific button. ("input" element)
The button is placed in http://example.com/welcome#_pg=compose
but when I open the page, following error occures:
TypeError: document.querySelector("#send_top") is null
#send_top is id of the button which I want to modify. So, the button is not found.
This error occurs because http://example.com/welcome and http://example.com/welcome#_pg=compose is completely different pages.
In this case, the addon seems loading http://example.com/welcome but there is no button whose '#send_top' ID.
When #_pg=compose anchor is added, the button is loaded by JavaScript.
How can I load http://example.com/welcome#_pg=compose to modify the button?

Three thoughts to help you debug this:
to correctly match the url you should consider using a regular expression instead of the page-match syntax - this might allow you to react to the anchors in a more predictable way
I've found that when using content scripts with pages that are heavily modified by JS, you can run into timing issues. A hacky workaround might be to look for the element you want and, if it isn' there, do a setTimeout for a 100 milliseconds or so and then re-check. Ugly, yes, but it worked for some example code I used with the new twitter UI, for example.
You can use the unsafeWindow variable in your content script to directly access the page's window object - this object will contain any changes JS has made to the page and is not proxied. You should use unsafeWindow with great caution however as its use represent a possible security problem. In particular, you should never trust any data coming from unsafeWindow, ever.

How does one properly test a javascript widget?

So, I've written a little javascript widget. All a user has to do is paste a script tag into the page, and right below it I insert a div with all of the content the user has requested.
Many sites do similar things, such as Twitter, Delicious and even StackOverflow.
What I'm curious about is how to test this widget to make sure that it will work properly on everyone's webpage. I'm not using an iframe, so I really want to make sure that this code will work when inserted most places. I know it looks the same in all browsers.
Suggestions? Or should I just build one hundred web pages and insert my script tag and see if it works? I would hope there is an easier way than that.

Once you have confirmed that your javascript works cross-browser in a controlled environment, here are some things that might cause problems when used on an actual website:
CSS
You're using a CSS class that is already being used (for a different purpose) by the target website
You're using positioning that might interfere with the site's CSS
The elements you are using are being styled by the website's CSS (you might want to use some sort of "reset" CSS that applies only to your widget)
HTML
You're creating elements with the same id attribute as an element that already exists on the website
You're specifying a name attribute that is already being used (while name can be used for multiple elements, you may not be expecting that)
Javascript
What is the expected behaviour without Javascript enabled? If your script creates everything, is it acceptable for nothing to be present without JS?

At very basic you should make sure your widget works for following test-cases. I am sure then it will work on all web-pages -
http/https: There should not be any warning for HTTPS pages for unencrypted content.
<script> / <no-script>: What if JavaScript is disabled? Is your widget still visible?
What happens when third-party cookies are disabled? Does your widget still work?
Layout-box restrictions: When parent div element's size is less than your widget. Does your widget overflow the given size and destroys owners page?

By keeping all your Javascripts under a namespace (global object) with a very unique name, you should be pretty much OK. Also, you can simply use an anonymous function if you just want to print out something.
Similar question: How to avoid name clashes in JavaScript widgets

How to dynamically add a Javascript function (and invoke)

Based on a click event on the page, via ajax I fetch a block of html and script, I am able to take the script element and append it to the head element, however WebKit based browsers are not treating it as script (ie. I cannot invoke a function declared in the appended script).
Using the Chrome Developer Tools I can see that my script node is indeed there, but it shows up differently then a script block that is not added dynamically, a non-dynamic script has a text child element and I cannot figure out a way to duplicate this for the dynamic script.
Any ideas or better ways to be doing this? The driving force is there is potentially a lot of html and script that would never be needed unless a user clicks on a particular tab, in which case the relevant content (and script) would be loaded. Thanks!

You could try using jQuery... it provides a method called .getScript that will load the JavaScript dynamically in the proper way. And it works fine in all well known browsers.

How about calling eval() on the content you receive from the server? Of course, you have to cut off the <script> and </script> parts.

If you're using a library like jQuery just use the built-in methods for doing this.
Otherwise you'd need to append it to the document rather than the head like this:
document.write("<scr" + "ipt type=\"text/javascript\" src=\"http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js\"></scr" + "ipt>");
In all honesty, I have no idea why the script tag is cut like that, but a lot of examples do that so there's probably a good reason.
You'll also need to account for the fact that loading the script might take quite a while, so after you've appended this to the body you should set up a timer that checks if the script is loaded. This can be achieved with a simple typeof check on any global variable the script exports.
Or you could just do an eval() on the actual javascript body, but there might be some caveats.
Generally speaking though, I'd leave this kind of thing up to the browser cache and just load the javascript on the page that your tabs are on. Just try not to use any onload events, but rather call whatever initializers you need when the tab is displayed.