Angular 4 sequential Http.post calls

Question

How to make sequential (synchronous) http POST calls (wait the response from each call)

generateDoc(project, Item, language, isDOCXFormat) : Observable<any> {
        return this.http.post(this.sessionStorageService.retrieve('backendApi').baseUri + '/export/document/' + project.projectId + '/' + Item.id,
                     {language:language, isDOCXFormat:isPDFFormat}, option);
    }

Thank you.

Possible duplicate of [How to chain Http calls in Angular2](https://stackoverflow.com/questions/34104638/how-to-chain-http-calls-in-angular2) — Nico Van Belle, Jul 07 '17 at 12:01

score 2 · Answer 1 · answered Jul 07 '17 at 11:59

2

If you want synchronous calls, you can use concatMap:

http.post(url1, data1).concatMap(t=> http.post(url2, data2);

answered Jul 07 '17 at 11:59

Michael Kang

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seems good, can you give me an example with generateDoc(params) method. Thank you – Debutantjsf Jul 07 '17 at 12:16

Angular 4 sequential Http.post calls

1 Answers1