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Formulas with parameters or App Settings
#7 Formulas using REST or WebApi Calls
Advanced Formula API
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Formulas using WebAPI and REST calls

Formulas can retrieve data from WebAPIs and REST. We have various examples of this on other pages, so this page will just repeat the examples from those page.

Important: Now using Formulas V2 🆕 in 2sxc 16
Formulas V2 has intellisense, stoppability, support for promises and more.

Get Data for a Field from a Web API

Get value for a field from a WebAPI

Try it:

    This formula is very advanced, and will initialize a fields value (if empty) from a WebAPI call.

    🆕 in v2 all formulas returning a promise are stopped by default!
    This is why the code is much simpler compared to v1.

    If ever necessary, the promise returned can specify to not stop the formula, but we don't need this for the current demo.


    Click on the (Σ) button above to see the edit-UI with the formula.

    Formulas of FormulasWebApiText.Title

    Field.Settings.Disabled (Formula-Target: Field.Settings.Disabled)

    v2((data) => {
  // Only enable once data has been loaded
  return !data.Title;
});

    Field.Value (Formula-Target: Field.Value)

    v2((data, context) => {
  // for demo reasons, don't do this till start is toggled.
  if (!data.Start) return data.value;
  
  // Call the sxc web-api controller from other tutorials
  return context.sxc.webApi.fetchJson('app/auto/api/basic/hello')
    .then(data => {
      console.log('got data', data); // log for demo reasons
      return data; // Use the result as the new value
    });
});

    Get dropdown options from WebAPI

    Try it:

      This is an advanced formula which will call a WebApi to get the possible values in a drop down. 


      Click on the (Σ) button above to see the edit-UI with the formula.

      Formulas of FormulasDropdownWebApi.Dropdown

      Field.Settings.DropdownValues (Formula-Target: Field.Settings.DropdownValues)

      v2((data, context) => {
  // Call the sxc web-api controller from other tutorials
  return context.sxc.webApi.fetchJson('app/auto/api/formulas/OptionsFromBackend')
    .then(data => {
      console.log('got data', data);// log for demo reasons
      // The result is a dictionary, so we convert to lines
      const lines = Object.keys(data)
        .map(k => k + ":" + data[k])
        .join('\n');

      return lines;
    });
});

      Get dropdown options from WebAPI accessing App.Data

      Try it:

        This is an advanced formula which will call a WebApi to get the possible values in a drop down - from Data in the App. 


        Click on the (Σ) button above to see the edit-UI with the formula.

        Formulas of FormulasDropDownWebApiData.Dropdown

        Setting DropdownValues (Formula-Target: Field.Settings.DropdownValues)

        v2((data, context) => {
  // Call the sxc web-api controller from other tutorials
  const promise = context.sxc.webApi.fetchJson('app/auto/api/formulas/Persons')
    .then(result => {
      console.log('got result', result);// log for demo reasons
      // The result is a dictionary, so we convert to lines
      return Object.keys(result)
        .map(k => k + ":" + result[k] + ' (' + k + ')')
        .join('\n');
    });

  // Return a loading value and a promise for later...
  return { value: data.value, promise };
});

        Source Code of ../api/FormulasController.cs

        Below you'll see the source code of the file. Note that we're just showing the main part, and hiding some parts of the file which are not relevant for understanding the essentials. Click to expand the code

        // Add namespaces for security check in Oqtane & DNN despite differences in .net core/.net Framework
// If you only target one platform, you can remove the parts you don't need
#if NETCOREAPP
using Microsoft.AspNetCore.Authorization; // .net core [AllowAnonymous] & [Authorize]
using Microsoft.AspNetCore.Mvc;           // .net core [HttpGet] / [HttpPost] etc.
#else
using System.Web.Http;                    // .net 4.5 [AllowAnonymous] / [HttpGet]
using DotNetNuke.Web.Api;                 // [DnnModuleAuthorize] & [ValidateAntiForgeryToken]
#endif
using System.Linq;        // this enables .Select(x => ...)
using System.Collections.Generic;          // To use the Dictionary

[AllowAnonymous]                          // all commands can be accessed without a login
public class FormulasController : Custom.Hybrid.Api14 // see https://r.2sxc.org/CustomWebApi
{
  [HttpGet]                               // [HttpGet] says we're listening to GET requests
  public object OptionsFromBackend()
  {
    var results = new Dictionary<string, string>() {
      { "first", "First option from WebApi" },
      { "second", "Second option from WebApi"},
      { "third", "3rd option" }
    };
    return results;
  }

  // Note: Persons just copied from Books Controller to test functionality
  [HttpGet]                               // [HttpGet] says we're listening to GET requests
  public dynamic Persons()
  {
    return AsList(App.Data["Persons"])
      .ToDictionary(x => x.EntityId.ToString(), p => p.FirstName + " " + p.LastName);
  }
}

// The next line is for 2sxc-internal quality checks, you can ignore this
// 2sxclint:disable:no-dnn-namespaces - 2sxclint:disable:no-web-namespace
        Formulas with parameters or App Settings
        #7 Formulas using REST or WebApi Calls
        Advanced Formula API

        Source Code of this file

        Below you'll see the source code of the file. Note that we're just showing the main part, and hiding some parts of the file which are not relevant for understanding the essentials. Click to expand the code

        @inherits Custom.Hybrid.Razor14
@using ToSic.Razor.Blade;
<!-- unimportant stuff, hidden -->


<div @Sys.PageParts.InfoWrapper()>
  @Html.Partial("../shared/DefaultInfoSection.cshtml")
  <div @Sys.PageParts.InfoIntro()>
    <h2>Formulas using WebAPI and REST calls</h2>
    <p>
      Formulas can retrieve data from WebAPIs and REST. 
      We have various examples of this on other pages, so this page will just repeat the examples from those page. 
    </p>
    @Html.Partial("./Part NowUsingV2.cshtml")
  </div>
</div>


@* Get Value from WebApi *@
<h2>Get Data for a Field from a Web API</h2>



@* Dropdown Values From WebAPI *@



@* Dropdown Values From WebAPI App.Data *@




@* Footer *@
@Html.Partial("../Shared/Layout/FooterWithSource.cshtml", new { Sys = Sys })