[typescript-angular] add support for httpResource

Add support for Angular httpResource.

The support is added only for GET request as adviced
by Angular docs:

```
TIP: Avoid using httpResource for mutations like POST or PUT.
Instead, prefer directly using the underlying HttpClient APIs.
```

non-GET methods still rely on rxjs.

Author: gonzalad

docs/generators/typescript-angular.md

@@ -297,6 +297,15 @@ public boolean getHasVendorExtensions() {
         return nonEmpty(vendorExtensions);
     }
 
+    /**
+     * Check if th httpMethod is a GET
+     *
+     * @return true if httpMethod is a GET, false otherwise
+     */
+    public boolean isGet() {
+        return "GET".equalsIgnoreCase(httpMethod);
+    }
+
     /**
      * Check if act as Restful index method
      *

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenOperation.java

@@ -38,6 +38,7 @@
 
 import java.io.File;
 import java.util.*;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -83,6 +84,7 @@ public static enum PROVIDED_IN_LEVEL {none, root, any, platform}
     public static final String RXJS_VERSION = "rxjsVersion";
     public static final String NGPACKAGR_VERSION = "ngPackagrVersion";
     public static final String ZONEJS_VERSION = "zonejsVersion";
+    public static final String USE_HTTP_RESOURCE = "useHttpResource";
 
     protected String ngVersion = "20.0.0";
     @Getter @Setter
@@ -96,6 +98,7 @@ public static enum PROVIDED_IN_LEVEL {none, root, any, platform}
     @Getter protected Boolean stringEnums = false;
     protected QUERY_PARAM_OBJECT_FORMAT_TYPE queryParamObjectFormat = QUERY_PARAM_OBJECT_FORMAT_TYPE.dot;
     protected PROVIDED_IN_LEVEL providedIn = PROVIDED_IN_LEVEL.root;
+    @Setter(AccessLevel.PRIVATE)  private boolean useHttpResource = false;
 
     private boolean taggedUnions = false;
 
@@ -155,6 +158,7 @@ public TypeScriptAngularClientCodegen() {
         this.cliOptions.add(new CliOption(RXJS_VERSION, "The version of RxJS compatible with Angular (see ngVersion option)."));
         this.cliOptions.add(new CliOption(NGPACKAGR_VERSION, "The version of ng-packagr compatible with Angular (see ngVersion option)."));
         this.cliOptions.add(new CliOption(ZONEJS_VERSION, "The version of zone.js compatible with Angular (see ngVersion option)."));
+        this.cliOptions.add(CliOption.newBoolean(USE_HTTP_RESOURCE, "Use httpResource to call GET endpoints").defaultValue(String.valueOf(this.useHttpResource)));
     }
 
     @Override
@@ -310,6 +314,11 @@ public void processOpts() {
         additionalProperties.put("isQueryParamObjectFormatJson", getQueryParamObjectFormatJson());
         additionalProperties.put("isQueryParamObjectFormatKey", getQueryParamObjectFormatKey());
 
+        if (additionalProperties.containsKey(USE_HTTP_RESOURCE)) {
+            this.setUseHttpResource(convertPropertyToBoolean(USE_HTTP_RESOURCE));
+        }
+        writePropertyBack(USE_HTTP_RESOURCE, getUseHttpResource());
+
     }
 
     @Data
@@ -434,7 +443,12 @@ public OperationsMap postProcessOperationsWithModels(OperationsMap operations, L
 
             // Prep a string buffer where we're going to set up our new version of the string.
             StringBuilder pathBuffer = new StringBuilder();
-            ParameterExpander paramExpander = new ParameterExpander(op, this::toParamName);
+            // If useHttpResource=true, means that we use signals and the variable is available under the name `this.toParamName(n) + "Value"`
+            Function<String, String> paramName =
+                    isUseHttpResource(op)
+                            ? n -> this.toParamName(n) + "Value"
+                            : this::toParamName;
+            ParameterExpander paramExpander = new ParameterExpander(op, paramName);
             int insideCurly = 0;
 
             // Iterate through existing string, one character at a time.
@@ -626,6 +640,10 @@ private String getApiFilenameFromClassname(String classname) {
         return toApiFilename(name);
     }
 
+    private boolean getUseHttpResource() {
+        return useHttpResource;
+    }
+
     @Override
     public String toModelName(String name) {
         name = addSuffix(name, modelSuffix);
@@ -766,4 +784,8 @@ public void setProvidedIn(String level) {
     private boolean getIsProvidedInNone() {
         return PROVIDED_IN_LEVEL.none.equals(providedIn);
     }
+
+    private boolean isUseHttpResource(CodegenOperation operation) {
+        return useHttpResource && operation.isGet();
+    }
 }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptAngularClientCodegen.java

@@ -1,9 +1,9 @@
 {{>licenseInfo}}
 /* tslint:disable:no-unused-variable member-ordering */
 
-import { Inject, Injectable, Optional }                      from '@angular/core';
+import { Inject, Injectable, Optional{{#useHttpResource}}, Signal{{/useHttpResource}} }                      from '@angular/core';
 import { HttpClient, HttpHeaders, HttpParams,
-         HttpResponse, HttpEvent{{#httpContextInOptions}}, HttpContext {{/httpContextInOptions}}
+         HttpResponse, HttpEvent{{#httpContextInOptions}}, HttpContext {{/httpContextInOptions}}{{#useHttpResource}}, httpResource, HttpResourceFn, HttpResourceRef{{/useHttpResource}}
         }       from '@angular/common/http';
 import { Observable }                                        from 'rxjs';
 import { OpenApiHttpParams, QueryParamStyle } from '../query.params';
@@ -67,263 +67,19 @@ export class {{classname}} extends BaseService {
     }
 
 {{#operation}}
-    /**
-{{#summary}}
-     * {{.}}
-{{/summary}}
-{{#notes}}
-     * {{.}}
-{{/notes}}
-     * @endpoint {{httpMethod}} {{{vendorExtensions.x-path-from-spec}}}
-     {{^useSingleRequestParameter}}
-     {{#allParams}}
-     * @param {{paramName}} {{description}}
-     {{/allParams}}
-     {{/useSingleRequestParameter}}
-     {{#useSingleRequestParameter}}
-     {{#allParams.0}}
-     * @param requestParameters
-     {{/allParams.0}}
-     {{/useSingleRequestParameter}}
-     * @param observe set whether or not to return the data Observable as the body, response or events. defaults to returning the body.
-     * @param reportProgress flag to report request and response progress.
-     * @param options additional options
-     {{#isDeprecated}}
-     * @deprecated
-     {{/isDeprecated}}
-     */
-    public {{nickname}}({{^useSingleRequestParameter}}{{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}{{/useSingleRequestParameter}}{{#useSingleRequestParameter}}{{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}RequestParams, {{/allParams.0}}{{/useSingleRequestParameter}}observe?: 'body', reportProgress?: boolean, options?: {httpHeaderAccept?: {{#produces}}'{{{mediaType}}}'{{^-last}} | {{/-last}}{{/produces}}{{^produces}}undefined{{/produces}},{{#httpContextInOptions}} context?: HttpContext{{/httpContextInOptions}}{{#httpTransferCacheInOptions}}, transferCache?: boolean{{/httpTransferCacheInOptions}}}): Observable<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>;
-    public {{nickname}}({{^useSingleRequestParameter}}{{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}{{/useSingleRequestParameter}}{{#useSingleRequestParameter}}{{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}RequestParams, {{/allParams.0}}{{/useSingleRequestParameter}}observe?: 'response', reportProgress?: boolean, options?: {httpHeaderAccept?: {{#produces}}'{{{mediaType}}}'{{^-last}} | {{/-last}}{{/produces}}{{^produces}}undefined{{/produces}},{{#httpContextInOptions}} context?: HttpContext{{/httpContextInOptions}}{{#httpTransferCacheInOptions}}, transferCache?: boolean{{/httpTransferCacheInOptions}}}): Observable<HttpResponse<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
-    public {{nickname}}({{^useSingleRequestParameter}}{{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}{{/useSingleRequestParameter}}{{#useSingleRequestParameter}}{{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}RequestParams, {{/allParams.0}}{{/useSingleRequestParameter}}observe?: 'events', reportProgress?: boolean, options?: {httpHeaderAccept?: {{#produces}}'{{{mediaType}}}'{{^-last}} | {{/-last}}{{/produces}}{{^produces}}undefined{{/produces}},{{#httpContextInOptions}} context?: HttpContext{{/httpContextInOptions}}{{#httpTransferCacheInOptions}}, transferCache?: boolean{{/httpTransferCacheInOptions}}}): Observable<HttpEvent<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
-    public {{nickname}}({{^useSingleRequestParameter}}{{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}{{/useSingleRequestParameter}}{{#useSingleRequestParameter}}{{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}RequestParams, {{/allParams.0}}{{/useSingleRequestParameter}}observe: any = 'body', reportProgress: boolean = false, options?: {httpHeaderAccept?: {{#produces}}'{{{mediaType}}}'{{^-last}} | {{/-last}}{{/produces}}{{^produces}}undefined{{/produces}},{{#httpContextInOptions}} context?: HttpContext{{/httpContextInOptions}}{{#httpTransferCacheInOptions}}, transferCache?: boolean{{/httpTransferCacheInOptions}}}): Observable<any> {
-{{#allParams}}
-{{#useSingleRequestParameter}}
-        const {{paramName}} = requestParameters{{^hasRequiredVars}}?{{/hasRequiredVars}}.{{paramName}};
-{{/useSingleRequestParameter}}
-{{#required}}
-        if ({{paramName}} === null || {{paramName}} === undefined) {
-            throw new Error('Required parameter {{paramName}} was null or undefined when calling {{nickname}}.');
-        }
-{{/required}}
-{{/allParams}}
-
-{{#hasQueryParamsOrAuth}}
-        let localVarQueryParameters = new OpenApiHttpParams(this.encoder);
-{{#queryParams}}
-
-        localVarQueryParameters = this.addToHttpParams(
-            localVarQueryParameters,
-            '{{baseName}}',
-            <any>{{paramName}},
-            {{#isQueryParamObjectFormatJson}}
-            QueryParamStyle.Json,
-            {{/isQueryParamObjectFormatJson}}
-            {{^isQueryParamObjectFormatJson}}
-            {{^style}}
-            {{#queryIsJsonMimeType}}
-            QueryParamStyle.Json,
-            {{/queryIsJsonMimeType}}
-            {{^queryIsJsonMimeType}}
-            QueryParamStyle.Form,
-            {{/queryIsJsonMimeType}}
-            {{/style}}
-            {{#style}}
-            {{#isDeepObject}}
-            QueryParamStyle.DeepObject,
-            {{/isDeepObject}}
-            {{#isFormStyle}}
-            QueryParamStyle.Form,
-            {{/isFormStyle}}
-            {{#isSpaceDelimited}}
-            QueryParamStyle.SpaceDelimited,
-            {{/isSpaceDelimited}}
-            {{#isPipeDelimited}}
-            QueryParamStyle.PipeDelimited,
-            {{/isPipeDelimited}}
-            {{#queryIsJsonMimeType}}
-            QueryParamStyle.Json,
-            {{/queryIsJsonMimeType}}
-            {{/style}}
-            {{/isQueryParamObjectFormatJson}}
-            {{isExplode}},
-        );
-
-{{/queryParams}}
-
-{{/hasQueryParamsOrAuth}}
-        let localVarHeaders = this.defaultHeaders;
-{{#headerParams}}
-        {{#isArray}}
-        if ({{paramName}}) {
-            localVarHeaders = localVarHeaders.set('{{baseName}}', [...{{paramName}}].join(COLLECTION_FORMATS['{{collectionFormat}}']));
-        }
-        {{/isArray}}
-        {{^isArray}}
-        if ({{paramName}} !== undefined && {{paramName}} !== null) {
-            localVarHeaders = localVarHeaders.set('{{baseName}}', String({{paramName}}));
-        }
-        {{/isArray}}
-{{/headerParams}}
-
-{{#authMethods}}
-        // authentication ({{name}}) required
-{{#isApiKey}}
-    {{#isKeyInHeader}}
-        localVarHeaders = this.configuration.addCredentialToHeaders('{{name}}', '{{keyParamName}}', localVarHeaders);
-    {{/isKeyInHeader}}
-    {{#isKeyInQuery}}
-        localVarQueryParameters = this.configuration.addCredentialToQuery('{{name}}', '{{keyParamName}}', localVarQueryParameters);
-    {{/isKeyInQuery}}
-{{/isApiKey}}
-{{#isBasic}}
-    {{#isBasicBasic}}
-        localVarHeaders = this.configuration.addCredentialToHeaders('{{name}}', 'Authorization', localVarHeaders, 'Basic ');
-    {{/isBasicBasic}}
-    {{#isBasicBearer}}
-        localVarHeaders = this.configuration.addCredentialToHeaders('{{name}}', 'Authorization', localVarHeaders, 'Bearer ');
-    {{/isBasicBearer}}
-{{/isBasic}}
-{{#isOAuth}}
-        localVarHeaders = this.configuration.addCredentialToHeaders('{{name}}', 'Authorization', localVarHeaders, 'Bearer ');
-{{/isOAuth}}
-
-{{/authMethods}}
-        const localVarHttpHeaderAcceptSelected: string | undefined = options?.httpHeaderAccept ?? this.configuration.selectHeaderAccept([
-    {{#produces}}
-            '{{{mediaType}}}'{{^-last}},{{/-last}}
-    {{/produces}}
-        ]);
-        if (localVarHttpHeaderAcceptSelected !== undefined) {
-            localVarHeaders = localVarHeaders.set('Accept', localVarHttpHeaderAcceptSelected);
-        }
-
-{{#httpContextInOptions}}
-        const localVarHttpContext: HttpContext = options?.context ?? new HttpContext();
-{{/httpContextInOptions}}
-{{#httpTransferCacheInOptions}}
-
-        const localVarTransferCache: boolean = options?.transferCache ?? true;
-{{/httpTransferCacheInOptions}}
-
-{{#bodyParam}}
-{{- duplicated below, don't forget to change}}
-        // to determine the Content-Type header
-        const consumes: string[] = [
-            {{#consumes}}
-            '{{{mediaType}}}'{{^-last}},{{/-last}}
-            {{/consumes}}
-        ];
-{{/bodyParam}}
-{{#hasFormParams}}
-{{^bodyParam}}
-        // to determine the Content-Type header
-        const consumes: string[] = [
-            {{#consumes}}
-            '{{{mediaType}}}'{{^-last}},{{/-last}}
-            {{/consumes}}
-        ];
-{{/bodyParam}}
-{{/hasFormParams}}
-{{#bodyParam}}
-        const httpContentTypeSelected: string | undefined = this.configuration.selectHeaderContentType(consumes);
-        if (httpContentTypeSelected !== undefined) {
-            localVarHeaders = localVarHeaders.set('Content-Type', httpContentTypeSelected);
-        }
-{{/bodyParam}}
-
-{{#hasFormParams}}
-        const canConsumeForm = this.canConsumeForm(consumes);
-
-        let localVarFormParams: { append(param: string, value: any): any; };
-        let localVarUseForm = false;
-        let localVarConvertFormParamsToString = false;
-{{#formParams}}
-{{#isFile}}
-        // use FormData to transmit files using content-type "multipart/form-data"
-        // see https://stackoverflow.com/questions/4007969/application-x-www-form-urlencoded-or-multipart-form-data
-        localVarUseForm = canConsumeForm;
-{{/isFile}}
-{{/formParams}}
-        if (localVarUseForm) {
-            localVarFormParams = new FormData();
-        } else {
-            localVarFormParams = new HttpParams({encoder: this.encoder});
-        }
-
-{{#formParams}}
-        {{#isArray}}
-        if ({{paramName}}) {
-        {{#isCollectionFormatMulti}}
-            {{paramName}}.forEach((element) => {
-                localVarFormParams = localVarFormParams.append('{{baseName}}{{#useSquareBracketsInArrayNames}}[]{{/useSquareBracketsInArrayNames}}', <any>element) as any || localVarFormParams;
-            })
-        {{/isCollectionFormatMulti}}
-        {{^isCollectionFormatMulti}}
-            if (localVarUseForm) {
-                {{paramName}}.forEach((element) => {
-                    localVarFormParams = localVarFormParams.append('{{baseName}}{{#useSquareBracketsInArrayNames}}[]{{/useSquareBracketsInArrayNames}}', <any>element) as any || localVarFormParams;
-            })
-            } else {
-                localVarFormParams = localVarFormParams.append('{{baseName}}{{#useSquareBracketsInArrayNames}}[]{{/useSquareBracketsInArrayNames}}', [...{{paramName}}].join(COLLECTION_FORMATS['{{collectionFormat}}'])) as any || localVarFormParams;
-            }
-        {{/isCollectionFormatMulti}}
-        }
-        {{/isArray}}
-        {{^isArray}}
-        if ({{paramName}} !== undefined) {
-            localVarFormParams = localVarFormParams.append('{{baseName}}', {{^isModel}}<any>{{paramName}}{{/isModel}}{{#isModel}}localVarUseForm ? new Blob([JSON.stringify({{paramName}})], {type: 'application/json'}) : <any>{{paramName}}{{/isModel}}) as any || localVarFormParams;
-        }
-        {{/isArray}}
-{{/formParams}}
-
-{{/hasFormParams}}
-    {{^isResponseFile}}
-        let responseType_: 'text' | 'json' | 'blob' = 'json';
-        if (localVarHttpHeaderAcceptSelected) {
-            if (localVarHttpHeaderAcceptSelected.startsWith('text')) {
-                responseType_ = 'text';
-            } else if (this.configuration.isJsonMime(localVarHttpHeaderAcceptSelected)) {
-                responseType_ = 'json';
-            } else {
-                responseType_ = 'blob';
-            }
-        }
-
-    {{/isResponseFile}}
-        let localVarPath = `{{{path}}}`;
-        const { basePath, withCredentials } = this.configuration;
-        return this.httpClient.request{{^isResponseFile}}<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>{{/isResponseFile}}('{{httpMethod}}', `${basePath}${localVarPath}`,
-            {
-    {{#httpContextInOptions}}
-                context: localVarHttpContext,
-    {{/httpContextInOptions}}
-    {{#bodyParam}}
-                body: {{paramName}},
-    {{/bodyParam}}
-    {{^bodyParam}}
-    {{#hasFormParams}}
-                body: localVarConvertFormParamsToString ? localVarFormParams.toString() : localVarFormParams,
-    {{/hasFormParams}}
-    {{/bodyParam}}
-    {{#hasQueryParamsOrAuth}}
-                params: localVarQueryParameters.toHttpParams(),
-    {{/hasQueryParamsOrAuth}}
-    {{#isResponseFile}}
-                responseType: "blob",
-    {{/isResponseFile}}
-    {{^isResponseFile}}
-                responseType: <any>responseType_,
-    {{/isResponseFile}}
-                ...(withCredentials ? { withCredentials } : {}),
-                headers: localVarHeaders,
-                observe: observe,
-    {{#httpTransferCacheInOptions}}
-                ...(localVarTransferCache !== undefined ? { transferCache: localVarTransferCache } : {}),
-    {{/httpTransferCacheInOptions}}
-                reportProgress: reportProgress
-            }
-        );
-    }
+{{#useHttpResource}}
+  {{#isGet}}
+    {{> operationHttpResource }}
+  {{/isGet}}
+{{/useHttpResource}}
+{{^useHttpResource}}
+    {{> operationObservable }}
+{{/useHttpResource}}
+{{#useHttpResource}}
+  {{^isGet}}
+    {{> operationObservable }}
+  {{/isGet}}
+{{/useHttpResource}}
 
 {{/operation}}}
 {{/operations}}