Disable the editing of a calculated field

Hello, Brendan,
 
Thank you for contacting us.
 
Controls dedicated to change the calculated values can be hidden using the following approach:
First of all, names and the captions of all calculated values which are required to be not editable have to contain the symbols mentioned by you: "~#".
 
In order to hide controls from the context menu that appears after the cell is clicked with a right-click, use the following function, allowing to customize the context menu:

pivot.customizeContextMenu(function(items, data, viewType) {
  if (data.measure && data.measure.formula && data.measure.uniqueName.includes("~#"))
    items.splice(3, 1);
  return items;
});

It scans each element of the menu and delete the one dedicated to editing in case the clicked value is the calculated one, and its name contains appropriate symbols.
 
Controls can be removed from the Field List, using the following code snippet:

pivot.on("fieldslistopen", () => {
  setTimeout(() => {
    let measuresList = document.querySelector("#fm-lst-measures").childNodes;
    for (let measure of measuresList)
      if (measure.childNodes[0].innerText.includes("~#"))
        measure.removeChild(measure.childNodes[1]);
  }, 0);
});

It uses the fieldslistopen event which is triggered after the Field List is opened and delete appropriate nodes dedicated to editing of the calculated value.
 
Please check out an example we have prepared for you.
 
Our team would like to kindly draw your attention to the fact that an example demonstrates the general approach of handling such a situation. It does not cover all use cases, e.g., it may work incorrectly for flat form.
 
More information about the customizeContextMenu API in our documentation.
Also, here is a page dedicated to the fieldslistopen event.
 
We hope it works for you.
Do not hesitate to contact us in case of additional questions.
 
Best regards,
Illia

Hello, Brendan,
 
Thank you for your feedback.
 
We would like to kindly notice that the provided solution is quite general. In order to remove other UI controls, additional logic may be required.
 
Concerning the blue icon from your screenshot, you are right about the fact that such elements are created dynamically. Thus, custom logic is required in order to track their creation and handle the removal of an appropriate icon.
 
We recommend considering the usage of the MutationObserver, which is a built-in JavaScript object that observes a DOM element and fires a callback in case of changes.
It allows tracking child nodes as well. Therefore, it is possible to trigger the function responsible for removing an appropriate icon as soon as new objects are created.
We recommend checking out the following page in order to get more information about the object and ways to use it.
 
Please let us know if the above solution works for you. In case it does not, our team can consider adding a property that allows making the value read-only in one of the future minor releases.
 
We are looking forward to hearing from you.
 
Best regards,
Illia

Hello, Brendan,
 
Our team would like to kindly take an interest in whether you did manage to implement the required functionality.
 
We are looking forward to hearing from you.
 
Best regards,
Illia

Hello, Brendan,

Our team is wondering if you succeeded to implement the disabling of editing calculated values.

Do not hesitate to write to us in case assistance is needed.

Best regards,
Illia