How to determine page mode (Edit/View) in Lightning Experience

Question

Please note that this is about Lightning Experience (with actions overridden), not Classic. So, getParameters() doesn't work here. Here is the output if someone needs to see it's output.

{id=XXXXX, isdtp=p1, nonce=XXXXX, sfdc.override=1, sfdcIFrameHost=web, sfdcIFrameOrigin=https://cs31.lightning.force.com}

I'm using Visualforce page in Lightning experience. The page is used to override edit/view pages.

In that page, there is button to open edit page which is binded to following function.

public PageReference customEdit() {

    PageReference viewPage = new ApexPages.StandardController(customer).edit();
    viewPage.setRedirect(true); 

    return viewPage;
}

When that button is clicked. URL is getting changed to .../edit

But how can i determine whether the page is in edit or view mode in the apex controller ?

View page URL -

https://cs31.lightning.force.com/one/one.app#/sObject/XXXXX/view

Edit page URL -

https://cs31.lightning.force.com/one/one.app#/sObject/XXXXX/edit

Answer 1

getParameters works in LEX as well as long as the parameter is passed correctly and is in the URL(may not be visible in the browser URL).

You can pass the parameter in the pageReference instance you have in your edit action.

public PageReference customEdit() {

    PageReference viewPage = new ApexPages.StandardController(customer).edit();
    viewPage.setRedirect(true); 
    viewPage.getParameters().put('pageMode', 'edit');
    return viewPage;
}

And then fetch the parameter value in the constructor of the controller of the edit page.

ApexPages.currentPage().getParameters().get('pageMode');