field.template(..., true) doesn't work in Embedded Entities view

[RichardBradley]

When using the "Embedded Entities" edit form, the field.template(x) function works fine to set a custom value template, but the field.template(x, true) function appears to have no effect.

To reproduce:

• open this Plunkr demo: http://plnkr.co/edit/YeOBmuIqqAGEcBGINtIw?p=preview

• click on "John" on the dashboard

• click "add new children"

• I have added the following fields to "user" and "child" (see script.js lines 45 - 58)):

      nga.field('custom value template')
        .template("custom value text"),
  
      nga.field('custom row template')
        .template("custom row text", true),
  

Expected behaviour:

I'd expect both the "user" form and the "child" form to have:

• one row which has a label "custom value template" and a value "custom value text"
• one row with just the text "custom row text" (no label)

Observed behaviour:

The user form has the above behaviour, but the child form has:

• one row which has a label "custom value template" and a value "custom value text"
• one row with a label "custom row template" and a text box

[RichardBradley]

The edit.hml and create.html templates where fields are instantiated use a "compile" directive to replace the row with the "template()" of the field, if "template(..., true)" has been called on that field:

    <div ng-repeat="field in ::formController.fields track by $index" compile="::field.getTemplateValueWithLabel(entry)">
        <ma-field field="::field" value="entry.values[field.name()]" entry="entry" entity="::entity" form="formController.form" datastore="::formController.dataStore"></ma-field>
    </div>

The corresponding code in maEmbeddedListField.js does not, hence this bug:

    <div class="form-field form-group" ng-repeat="field in ::fields track by $index">
        <ma-field field="::field" value="entry.values[field.name()]" entry="entry" entity="::targetEntity" form="formName" datastore="::datastore()"></ma-field>
    </div>

However, the obvious fix of applying "compile" in both places has a problem in that the "default" template string differs between the two contexts. In the first context, the default template is the "<ma-field" string as seen above and listed in the docs. In the second context, the default template is similar, but has different attribute values.

I think this will make "template()" tricky to use correctly. However, fixing that issue is much harder and feels out of scope here.

[RichardBradley]

I have created a PR which applies the obvious fix here.

As noted above, there is still a bit of an ugly API here, as the the "default" template string differs between the two contexts.

If I want to be able to show / hide edit rows based on the entity values, like http://stackoverflow.com/questions/35934085/ng-admin-how-to-show-different-fields-according-to-users-selection then I need to change the template based on whether the field is "embedded" or not.

Let's say I want to write a decorator named "showEditCreateIf" which will show/hide an edit/create field based on a field value. Using the same example as the the Field Configuration doc page:

post.editionView()
      .fields([
          nga.field('category', 'choice')
              .choices([
                  { label: 'Tech', value: 'tech' },
                  { label: 'Lifestyle', value: 'lifestyle' }
              ]),
          nga.field('subcategory', 'choice')
              .choices(function(entry) {
                  return subCategories.filter(function (c) {
                      return c.category === entry.values.category;
                  });
              })
              // display subcategory only if there is a category
              .showEditCreateIf("entry.values.category"),
      ]);

Here's a decorator I'm currently using that lets me write code like that, but it's ugly for the reason discussed above:

// Overrides for admin-config/lib/Field/Field.js
myapp.config(function(NgAdminConfigurationProvider) {

    var fieldProto = Object.getPrototypeOf(NgAdminConfigurationProvider.field(""));

    // Use this to add an "ng-if" to the field row in edit / create view.
    // `entry.values[x]` can be used to test the current value of entity properties
    //
    //   e.g. to show subcategory only if there is a category
    //     nga.field('subcategory', 'choice')
    //        .showEditCreateIf('entry.values.category')
    //
    fieldProto.showEditCreateIf = function(expressionStr) {
        if (!this.template()) {
            throw "You cannot use both `showEditCreateNgIf` and `template`";
        }

        this.template(function(entry) {

            var maField = document.createElement('ma-field');

            if (entry._entityName) {
                // This is the standard template, from
                //     ng-admin/Crud/form/edit.html
                // and ng-admin/Crud/form/create.html
                maField.setAttribute('field', '::field');
                maField.setAttribute('value', 'entry.values[field.name()]');
                maField.setAttribute('entry', 'entry');
                maField.setAttribute('entity', '::entity');
                maField.setAttribute('form', 'formController.form');
                maField.setAttribute('datastore', '::formController.dataStore');
            } else {
                // This is the standard template when the field is used
                // in an embedded entity context
                // See ng-admin/Crud/field/maEmbeddedListField.js
                maField.setAttribute('field', '::field');
                maField.setAttribute('value', 'entry.values[field.name()]');
                maField.setAttribute('entry', 'entry');
                maField.setAttribute('entity', '::targetEntity');
                maField.setAttribute('form', 'formName');
                maField.setAttribute('datastore', '::datastore()');
            }

            maField.setAttribute('ng-if', expressionStr);

            return maField.outerHTML;
        }, true);

        return this;
    };
});

Any ideas? Maybe the template() API needs a rethink, or do we need a native "showEditCreateIf" on fields?