Combine csr with PreSave into one file for New and Edit forms

Question

I'm trying to combine all the pieces I need into one external client side rendering file so I only need to maintain one file for my list.

When we create a new item in the list there are some csr things I want to do on the NewForm when I render it, and I mostly have the CSR working for that. Upon save, there I have a custom PreSaveAction that creates some other list items and modifies the user input on the page.

When editing an existing item, there are some different things I want to do with the colums and I have the csr doing that correctly. I also want to have a custom PreSaveAction, but this time it needs to just updated the other list items it created on the new form.

Basically I control for New vs Edit in the csr like this

customContext.Templates.Fields = {
    'SpecialColum': { "NewForm": NewFormRender,
                      "EditForm": EditRenderFunction}
}

And that knows which form we're on because that is how it was designed to function.

I see that ctx.BaseViewID is a value of either NewForm or EditForm. But by the time I get to my custom PreSaveAction the ctx is long gone.

How do I pass the context BaseViewID to my PreSaveAction?

Answer 1

Presuming that you did not modify the default webpart on the NewForm and EditForm webpages, then you should be able to access a global JS object named WPQ2FormCtx. This object is loaded before the CSR is executed. The CSR is actually using the contents of this object for things like populating the input fields with values on the EditForm webpage, etc.

So, what you need to do inside the PreSaveAction function is the following:

function PreSaveAction() {
    if (WPQ2FormCtx.FormControlMode === 3) {

        // execute code for NewForm page here

    } else if (WPQ2FormCtx.FormControlMode === 2) {

        // execute code for EditForm page here

    }
}

Personally, I suggest you keep your JS files separate because they will be shorter so they will load and execute faster. Also, nobody can guarantee you 100% that the WPQ2FormCtx object will not become WPQ3FormCtx, although it should not if nobody is messing with the web parts.

---

The way I approached something similar in the past was to create a variable on my global object (I always use only one global variable which is an object and to which I attach functions and other objects) and then set this variable inside the function used for the CSR of the first field in the form.

For example, I would do this:

// My global object.
var myGlobalObject = {...};

// CSR functions here.
myGlobalObject.NewFormRender = function NewFormRender(ctx) {
    myGlobalObject.baseViewID = ctx.BaseViewID;

    // more code here...
};

// more code here...

function PreSaveAction() {
    if (myGlobalObject.baseViewID === 'NewForm') {

        // execute code for NewForm page here...

    } else if (myGlobalObject.baseViewID === 'EditForm') {

        // execute code for EditForm page here...

    }
}

Note that the NewFormRender function above is the one you used for your SpecialColum field. You only need to do this in one of your custom rendering functions.

Answer 2

You could try changing the Scope for the PreSaveAction with

function PreSaveAction(){
   var baseviewId=this;

}.bind(ctx.BaseViewId);

But easier might be to just whack it in the global scope
people who say the global scope is evil, don't understand JavaScript

window.MYBaseViewID = ctx.BaseViewID;