I am looking for solution to pass parameters from the current page to a previous page and way how to check that the page was popped from another page in Xamarin.Forms.
Thanks !
To pass information from one page to another you can either use events or MessagingCenter: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/messaging-center.
As a personal suggestion, I would try events first, if you cant achieve whatever you want with plain events, then you should give a look to MessagingCenter.
But as a TL;DR, the MessagingCenter allows components/viewmodels to communicate without knowing anything about each other.
Related
I have some check boxes on my website selecting which the data on the page gets filtered but the page name remains the same. I want to capture the data for visitors selecting any of the check boxes. Can you please let me know how can this be done?
Presently, I have different page name whenever the user select any of the check box. But by doing this, Page views data for that page becomes irrelevant.
For Omniture tracking, that's very possible, but you need to add a bit of javascript. You need to add an onClick event for the checkbox, and have it submit a custom link event to Adobe. They provide a function for it:
s.tl(this, 'o', 'Checkbox X Clicked');
Prior to this call, you can set props/evars if you want other tracking tied to this event. It doesn't count as a page view, though.
The Omniture implementation guide is here:
http://microsite.omniture.com/t2/help/en_US/sc/implement/oms_sc_implement.pdf... do a search for the s.tl() function. It'll explain.
Presumably, your page has JavaScript that does the filtering.
You would need to add to this JavaScript to send an AJAX request to the server every time the user makes their selection. The server will need to track the requests in a database or a file. After that, you can analyse the results.
There are many ways to send AJAX requests in JavaScript. The basics are here: http://www.w3schools.com/ajax/default.asp but there are also 3rd party libraries available.
Unfortunately there is nothing that "google-analytics' can do for you here, as far as I know.
Good luck,
DC
I'm using Spring and would like to find out if there is some technique that can be used to stay on the same page. So, to be more clear, after you click on a link and the handler executes, there is some condition which dictates that the browser should remain on (or be redirected/forwarded to) the page the browser was currently on. Beehive, which is built on top of Struts, has a way to do this and I'm wondering if Spring has something similar.
It really depends on the use case. Are you submitting a form or something similar that could be submitted through XHR instead? If you can't use XHR, a simple solution is to have the controller return a view to the current page, possibly with some additional state information.
I'm writing an asp.net web app. and i've hit a bit of a brick wall.
basically i have 2 pages, the main page with a text box in and a popup that contains a treeview.
My problem is this. when i select a treeview item i want the program to perform some database transactions using asp.net and then pass the value retrieved from the database into a javascript function that passes the data back from the popup page to the parent page. My problem is that i cannot find any way of calling a javascript function from asp.net. I've tried assigning attributes to controls on page load, but this does not work as when the page loads the data has not been retrieved from the database.
Have a look at the ClientScriptManager class. You can register scripts from code-behind that will run when the HTML page loads. Those scripts can call other javascript functions on the page.
There are many tutorials and examples on the Web. Here's one I found that may help but there are many more.
How to use the client script manager
You hit the nail on the head when you said "I've tried assigning attributes to controls on page load, but this does not work as when the page loads the data has not been retrieved from the database." You just need to discover when you're pulling the data from the database, and then assign the values after that. Without looking at your code, there's no way to know for sure, but Page_PreRender is probably a good bet to assign your values...it's probably after you're pulling information from the db...it's pretty much the last place that you can make things happen before the html is generated for the client.
You can invoke a function resided in the Main Page and call that function in the Main Page from the Child Page which is your pop up window.
Please refer to these links for references
http://chiragrdarji.wordpress.com/2007/03/10/call-parent-windows-javascript-function-from-child-window-or-passing-data-from-child-window-to-parent-window-in-javascript/
http://www.webmasterworld.com/forum91/2957.htm
http://hspinfo.wordpress.com/2008/01/12/call-parent-windows-javascript-function-from-child-window/
This one helps with retrieving popups from values using javascript
http://www.eggheadcafe.com/articles/20060117.asp
This one shows how to fire a postback using javascript, and manage it in the codebehind.
http://weblogs.asp.net/mnolton/archive/2003/06/04/8260.aspx
If you put them together, and use Control.ClientID to find the actual "html name" of your asp.net controls, you'll be able to set that up in no time.
Might not be the prettiest way to do it in town, and incidentally make little baby Jesus cry, but anyway, it works.
[edit]Oh. I just saw that it seems I answered the question the other way around, or "how to trigger codebehind from Javascript". I think the method I suggest may help you, if you use it right.
The javascript of the popup should pass the information to the parent window, and the parent window function should call a postback when it receives the information.
The javascript of the popup window should be only registered on a postback with the correct information retrieved, so that when the postback occurs on the popup because of the selection of the right information, the window closes and passes the information to the parent page.
The parent page, triggering postback, does the thingies you need it to, and the app resumes "normally" from there on, doing whatever you need it to, outside of the popup page.
I have a wizard style interface where I need to collect data from users. I've been asked by my managers that the information is to be collected in a step by step type process.
I've decided to have a page.aspx with each step of the process as a separate user control. step1.ascx step2.ascx etc...
The way it works now, is that when the initial GET request comes in, I render the entire page (which sits inside of a master page) and step1.ascx. When then next POST request comes in for step 2 (using query string step=2), I render only step2.ascx to the browser by overriding the Render(HtmlTextWriter) method and use jQuery html() method to replace the contents of a div.
The problem with this whole approach, besides being hacky (in my opinion) is that it's impossible to update viewstate as this is usually handled server side.
My workaround is to store the contents of step1.ascx into temporary session storage so if the user decides to click the Back button to go back one step, I can spit out the values that were stored for it previously.
I feel I'm putting on my techy hat on here in wanting to try the latest Javascript craze as jQuery with .NET has taken a lot of hack like approaches and reverse engineering to get right. Would it be easier to simply use an updatepanel and be done with it or is there a site with a comprehensive resource of using jQuery to do everything in ASP.NET?
Thanks for taking the time to read this.
Another approach, that might be easier to work with, is to load the entire form with the initial GET request, and then hide all sections except the first one. You then use jQuery to hide and show different parts of the form, and when the final section is shown the entire form is posted in one POST to the server. That way you can handle the input on the server just as if the data entry was done in one step by the user, and still get the step-by-step expreience on the client side.
You could just place all your user controls one after another and turn on the visibility of the current step's control and turn on other controls when appropriate . No need to mess with overriding Render(). This way the user controls' viewstate will be managed by the server. and you can focus on any step validation logic.
Using an UpdatePanel to contain the steps would give the ajax experience and still be able to provide validation on each step. If you are OK with validating multiple steps at once, Tomas Lycken's suggestion (hide/show with JQuery), would give a fast step by step experience.
Did you look into using the ASP.NET Wizard control? It's a bit of a challenge to customize the UI, but otherwise it's worked well for me in similar scenarios.
Clarification:
Put simply, I'd like to put an ASP.NET UpdatePanel inside the info window of Google Maps. This would mean that users could interact with my application from within an info window, without refreshing the page and without closing the currently open info window.
Does anyone know if this is possible?
Update:
Thank you to all those who have so far responded. Very much appreciated.
What I have gleaned from the answers is that:
the update panel has it's own "mysterious mechanics" which might be causing the UpdatePanel to not work correctly inside the InfoWindow. Going down the more direct route of using JQuery to make ajax calls to simple web services should eliminate the hidden complexity of the UpdatePanel and enable the functionality I want.
I am still intrigued as to why the UpdatePanel approach does not work, and as to why using one would "break the model" of Google Maps, when surely an UpdatePanel merely renders as HTML and javascript with a link to the XMLHttpRequest object.
Is it possible to place ASP.NET code inside Google Maps info window?
I'd like to place an UpdatePanel with some AJAXified asp:Button's inside the info window.
AFAICT you simply provide the HTML to place in the info window as a string, so was thinking of rendering a UserControl to a string and placing that string in the info window for the browser to render. Does anyone know if this is likely to work?
If this is not possible in Google maps, does anyone have any idea whether such an implementation would be possible with the corresponding Virtual Earth technology?
José Basilio is right. Instead, use $jquery Live Events and put regular HTML in the Info Window then use Ajax calls with jQuery to get the interactivity you want. Reframe the problem.
VirtualEarth has tigether integration with SilverLight, which should mean that you'll have greater .NET control over your web mapping application. With most Google Maps implementations that we've done we typically just use pure HTML/JavaScript/CSS solutions to create AJAX functionality. Thus we would inject HTML/javascript into the InfoWindow class, for any custom functionality that we needed.
Consider another approach and possibly. What you are really looking for is to be able to respond to a server side event. Maybe something like this if you really and truely need to respond to server side events.
http://windyroad.org/2006/07/25/event-driven-ajax-part-1-pushing-server-side-events/
Once you are handling the events on the client in javascript you can do whatever you like to the map
I'm not sure I'd take this approach, but if you want to get ASP.NET code within an info window, you could use an iframe.
Alternatively have you considered an ASP.NET control such as GoogleMap Control, which would handle all the integration for you?
Rich
UpdatePanel != AJAX. Take a look at using jQuery to make Ajax calls ($.ajax) and creating simple web services/etc. to achieve what you're after. While technically you could wiggle an UpdatePanel into there somehow, it just isn't worth it.
Look here for an excellent example on calling AJAX/web methods with jQuery.
Have you looked at the ExtInfoWindow control? Since you did not state your problem, I can't say whether it is a solution, but it seems that it should be mentioned here.