Tips for enhancing parameters in TypeScript/Angular methods

Question

Tips for enhancing parameters in TypeScript/Angular methods

I'm working with a function that has multiple parameters:

public find(
    cadnum: string,
    pagesize: number,
    startid?: string
  ): Observable<any> {
    let url = "";

    if (cadnum) {
       url+= "?cadnum=" + cadnum;  
    }

     if (pagesize) {
       url+= "&pagesize=" + pagesize;  
    }

 if (startid) {
       url+= "&startid=" + startid;  
    }

    return this.httpClient.get(url);
}

It seems like there may be a better way to handle checking and concatenating the URL string, especially when dealing with more parameters. Any suggestions on how to improve this process?

angular typescript

Answer 1

Answer №1

The simplification of the above code snippet can be seen below:

return this.httpClient.get(url, { 
  headers: { 'Content-Type': 'application/json' },
  params: {
    cadnum, 
    pagesize,
    startid,
  },
});

Another approach is to consolidate the parameters of the find function into an object before sending it to the httpClient:

const params: HttpParams = {
  cadnum, 
  pagesize,
  startid,
  // other parameters 
};

return this.httpClient.get(url, { 
  headers: { 'Content-Type': 'application/json'},
  params, 
});

Answer 2

The simplification of the above code snippet can be seen below:

return this.httpClient.get(url, { 
  headers: { 'Content-Type': 'application/json' },
  params: {
    cadnum, 
    pagesize,
    startid,
  },
});

Another approach is to consolidate the parameters of the find function into an object before sending it to the httpClient:

const params: HttpParams = {
  cadnum, 
  pagesize,
  startid,
  // other parameters 
};

return this.httpClient.get(url, { 
  headers: { 'Content-Type': 'application/json'},
  params, 
});

Answer 3

Answer №2

Utilize an Object as a parameter and iterate through its attributes

// Transforming an object into HttpParams
// Found this function in JHipster :p
const createRequestOption = (params?: any): HttpParams => {
    let options: HttpParams = new HttpParams();
    if (params) {
        Object.keys(params).forEach(key => {
            if (req[key] != null) {
                options = options.set(key, req[key]);
            }
        });
    }
    return options;
};

public find(params? :any): Observable<any> {
    const url = 'http://...';
    const options = createRequestOption(params);
    return this.httpClient.get(url, { params: options});
}

If you prefer strong typing, this approach should also work

public find(params: {
    cadnum: string,
    pagesize: number,
    startid?: string
}): Observable<any> {
    const url = 'http://...';
    const options = createRequestOption(params);
    return this.httpClient.get(url, { params: options});
}

Answer 4

Utilize an Object as a parameter and iterate through its attributes

// Transforming an object into HttpParams
// Found this function in JHipster :p
const createRequestOption = (params?: any): HttpParams => {
    let options: HttpParams = new HttpParams();
    if (params) {
        Object.keys(params).forEach(key => {
            if (req[key] != null) {
                options = options.set(key, req[key]);
            }
        });
    }
    return options;
};

public find(params? :any): Observable<any> {
    const url = 'http://...';
    const options = createRequestOption(params);
    return this.httpClient.get(url, { params: options});
}

If you prefer strong typing, this approach should also work

public find(params: {
    cadnum: string,
    pagesize: number,
    startid?: string
}): Observable<any> {
    const url = 'http://...';
    const options = createRequestOption(params);
    return this.httpClient.get(url, { params: options});
}

Answer 5

Answer №3

Revise your function to accept an array as a parameter, then iterate through each value to construct the corresponding URL.

public generateURL(
    parameters: any[]
  ): Observable<any> {
    let url = "";

parameters.forEach(function (value) {

if (value) {
       url+= "&" + value + "=" + value;  
    }
});

}

Answer 6

Revise your function to accept an array as a parameter, then iterate through each value to construct the corresponding URL.

public generateURL(
    parameters: any[]
  ): Observable<any> {
    let url = "";

parameters.forEach(function (value) {

if (value) {
       url+= "&" + value + "=" + value;  
    }
});

}

Tips for enhancing parameters in TypeScript/Angular methods

Answer №1

Answer №2

Answer №3

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