My coworker and I have encountered a nasty situation where we have to use an active X control to manipulate a web camera on a page.
Is it possible to assign a javascript event handler to a button in the active x control so that it would fire an action on the page when clicked, or do we have to create a button on the html page itself that manipulates the Active X Control and then can fire any necessary actions on the page?
Please just use an existing ActiveX control. Like Flash or Silverlight. Flash has built-in webcam support and is controllable via JavaScript. Silverlight doesn't have built-in camera support, but it's JavaScript integration is fantastic.
If you must write your own then fret not, it is trivial to get it to interact with JavaScript. You just have to expose the IDispatch interface.
For events, you need to learn about Connection Points.
Yes! You can throw events in C++/ActiveX land which makes the JavaScript code run an event handler function. I was even able to make an entire invisible ActiveX control (same color as page background) with no buttons or visual feedback that did all of its GUI work through JavaScript and CSS.
edit: Frank's advice is right on. Here's the link on scripting events.
My strategy was to call a C++ function called MyUpdate (which implements IConnectionPoint) when I wanted to force updates in the browser.
(Also, I made sure to pump Windows messages in the Fire_MyUpdate method because sometimes JavaScript code would call back into C++ land by calling methods on the ActiveX control; this avoids freezing up the browser and ensures that the JavaScript GUI stays responsive, e.g. for a Cancel button.)
On the browser side, the JavaScript code has the global variable referencing the object, followed by "::", followed by the method name:
function Uploader::MyUpdate()
{
// ... code to fetch the current state of various
// properties from the Uploader object and do something with it
// for example check Uploader.IsActive and show or hide an HTML div
}
Related
I have a WinForms app that uses a .NET webbrowser control. What I need to do, is wire up an event on the WinForms side to fire when a value is set (via javascript) in the loaded HTML page. I had success doing this with an onclick event of a button, but I can't seem to get it to work with a custom event. I don't know if this is a limitation in what the browser control can attach to event wise.
So essentially, I need that when a JS function is called in the HTML page and sets a value of a hidden input element (or it could be a regular input that I style to be hidden), I need to know that in WinForms. If it helps, I am using browser flags in this application to emulate IE11 instead of the default IE9 engine. The HTML page loaded is also mine so I can modify it any way needed to make this work properly. I would just use the onclick events of the buttons, but this is a gmaps integration where there can be upwards of 2000 buttons generated (one per marker placed) so it seems like a huge waste of resources to wire up 2000 onclick events when any of those button clicks only modify 4 input fields with the data I care about.
This project happens to be in VB.NET, but C# solutions would be fine as well. They can be transcoded or if the solution uses C# specific features, we can move this to a separate DLL and reference it.
After spending a lot of time on this today, I found a solution. It isn't a direct solution to the problem I posted, but it got me to where I needed to be. I am still interested in an answer to the original problem if anyone has one, but for now, what I found I could do was to create a class in .NET that I could assign to the ScriptingObject of the browser control and then call window.external.myFunctionName, where myFunctionName is a function within the .NET class. This works great for my specific problem, but would not work if I didn't also control the HTML page I was consuming with the browser. That is why I am still interested in alternate solutions if anyone has one. Thanks.
In a javascript function, I want to open the window that is usually opened when the user clicks on the "Assign" button in the lead form.
In the ribbon workbench, I see that the function that is called on the click of Assign is XrmCore.Commands.Assign.assignObjectLegacy, in the library Main_system_library.js.
Is it possible to call this function in javascript?
Doing such things like using internal libraries, calling internal methods are unsupported in Dynamics CRM. Future version of product changes may affect this implementation.
Instead, try to use jQuery to find the button element & invoke the onclick event like $('#assignbuttonid').click(). This is too unsupported because we cannot use DOM manipulation but somewhat ok.
Otherwise I don’t see any alternate supported solution to do this.
Using jQuery is one way to mimic the feature but like Arun said it's unsupported and risk to break in the next update. Instead, I would call a custom action. An action is basically a workflow. You can assign your entity via javascript and it will be supported.
Here is a sample you can use: https://community.dynamics.com/crm/b/nishantranaweblog/archive/2017/05/27/sample-code-to-call-action-using-web-api-in-crm
I am currently trying to write a script using javascript along side a bit of html and some css - but let's stick with Javascript as thats where, I think, my problem comes from...
In short what I want my program to do is these following points:
I have an iFrame in the main window of my program.
The iFrame is used to access a website (obviously duh :P)
There is a button outside of the iFrame.
That button will call a function when pressed by the user.
HERE'S MY PROBLEM:
I want that function to simulate the press of a keyboard key (in that case, a number key followed by the ENTER key twice.
The thing is, I need to 'simulate' these keypress inside the iFrame, so they interact with the website that is access through the iFrame.
In short, I can't seem to find a way to interact with the website in iFrame from outside of it. I would prefer a solution using pure JS but I'm fully aware that there would probably be a much simpler solution using Jquery. So I'm open to either one of them.
I don't think that pieces of my code would help as there is basically nothing coded so far, besides the main function and the basic layout of the page. I'm ready to redo the whole architecture of what I've done so far if needed.
Thanks for you help.
Yann
I'm making a game using JavaScript, currently I'm using window.location = "somepage.html" to perform navigation but I'm not sure if that is the correct way to do it. As I said in the title I've choosed Blank App Template so I do not have any navigator.js or something like.
Can you guys tell me the best way to do it?
Although you can use window.location to perform navigation, I'm sure you've already noticed a few of the downsides:
The transition between pages goes through a black screen, which is an artifact of how the underlying HTML rendering engine works.
You lose your script context between pages, e.g. you don't have any shared variables or namespaces, unless you use HTML5 session storage (or WinRT app data).
It's hard to wire up back buttons, e.g. you have to make sure each destination page knows what page navigated to it, and then maintain a back stack in session storage.
It's for these reasons that WinJS + navigator.js created a way to do "pages" via DOM replacement, which is the same strategy used by "single page web apps." That is, you have a div in default.html within which you load an unload DOM fragments to give the appearance of page navigation, while you don't actually ever leave the original script context of default.html. As a result, all of your in-memory variables persist across all page navigations.
The mechanics work like this: WinJS.Navigation provides an API to manage navigation and a backstack. By itself, however, all it really does is manage a backstack array and fire navigation-related events. To do the DOM replacement, something has to be listening to those events.
Those listeners are what navigator.js implements, so that's a piece of code that you can pull into any project for this purpose. Navigator.js also implements a custom control called the PageControlNavigator (usually Application.PageControlNavigator) is what implements the listeners.
That leave the mechanics of how you define your "pages." This is what the WinJS.UI.Pages API is for, and navigator.js assumes that you've defined your pages in this way. (Technically speaking, you can define your own page mechanisms for this, perhaps using the low-level WinJS.UI.Fragments API or even implementing your own from scratch. But WinJS.UI.Pages came about because everyone who approached this problem basically came up with the same solution, so the WinJS team provided one implementation that everyone can use.)
Put together then:
You define each page as an instance of WinJS.UI.Pages.PageControl, where each page is identified by its HTML file (which can load its own JS and CSS files). The JS file contains implementations of a page's methods like ready, in which you can do initialization work. You can then build out any other object structure you want.
In default.html, define a single div for the "host container" for the page rendering. This is an instance of the PageControlNavigator class that's defined in navigator.js. In its data-win-options you specify "{home: }" for the initial page that's loaded.
Whenever you want to switch to another page, call WinJS.Navigation.navigate with the identifier for the target page (namely the path to its .html file). In response, it will fire some navigating events.
In response, the PageControlNavigator's handlers for those events will load the target page's HTML into the DOM, within its div in default.html. It will then unload the previous page's DOM. When all of this gets rendered, you see a page transition--and a smooth one because we can animate the content in and out rather than go through a black screen.
In this process, the previous page control's unload method is called, and the init/load/processed/ready methods of the new page control are called.
It's not too hard to convert a blank app template into a nav template project--move your default.html/.css/.js content into a page control structure, add navigator.js to default.html (and your project), and put a PageControlNavigator into default.html. I suggest that you create a project from the nav app template for reference. Given the explanation above, you should be able to understand the structure.
For more details, refer to Chapter 3 of my free ebook, Programming Windows Store Apps with HTML, CSS, and JavaScript, Second Edition, where I talk about app anatomy and page navigation with plenty of code examples.
I am working on a web page that contains check boxes that do some stuff when they are clicked, or changed. There is no explicit event binding in the HTML itself. I have literally no idea how the event binding has been done and no way to find what JavaScript is being run when the checkboxes are changed (other than the page uses jQuery in other places).
The JavaScript itself is spread out in several locations in the HTML itself, plus in a whole bunch of additional JavaScript files. This would make just sticking breakpoints everywhere in the JavaScript difficult.
Is there any way, using some debugging environment for example, to find out what JavaScript is run when I change the values of these checkboxes?
Go to scripts tab in google chrome developer tools and set an Event Listener Breakpoint to a change event (or click event, whatever they are using) and go click a checkbox. It will then stop execution right away and you may manually walk through the whole execution process, function by function.