QueryString Parser

Parse QueryString from the HTTP request into an object.

Logic type	Input	Output
Generic	ctx.payload()	Session variable params (type: any or null if not parsed successfully)

JavaScript

querystring-parser.js

import {
    LoggingAgent,
    SessionStorageAgent
} from "@fstnetwork/loc-logic-sdk";

export async function run(ctx) {
    // read payload
    const payload = await ctx.payload();

    if (!("http" in payload)) throw new Error("this logic only accepts http request");

    // get querystring (skip if empty)
    const query = payload.http.request.query;
    if (!query) return;

    let params = null;
    try {
        // parse querystring to object
        params = Object.fromEntries(new URLSearchParams(query));
    } catch (e) {
        LoggingAgent.warn({
            error: true,
            errorMessage: `unable to parse QueryString parameters: ${e.message}`
            stack: e.stack,
            taskKey: ctx.task.taskKey,
        });
    }

    // log parsed querystring
    LoggingAgent.info({ params: params });

    // write the parsed data into session storage
    await SessionStorageAgent.putJson("params", params);
}

export async function handleError(ctx, error) {
    // error logging
    LoggingAgent.error({
        error: true,
        errorMessage: error.message,
        stack: error.stack,
        taskKey: ctx.task.taskKey,
    });
}

JavaScript (with JSDoc)

querystring-parser.js

import {
    LoggingAgent,
    SessionStorageAgent
} from "@fstnetwork/loc-logic-sdk";

/** @param {import('@fstnetwork/loc-logic-sdk').GenericContext} ctx */
export async function run(ctx) {
    // read payload
    const payload = await ctx.payload();

    if (!("http" in payload)) throw new Error("this logic only accepts http request");

    // get querystring (skip if empty)
    const query = payload.http.request.query;
    if (!query) return;

    let params = null;
    try {
        // parse querystring to object
        params = Object.fromEntries(new URLSearchParams(query));
    } catch (e) {
        LoggingAgent.warn({
            error: true,
            errorMessage: `unable to parse QueryString parameters: ${e.message}`
            stack: e.stack,
            taskKey: ctx.task.taskKey,
        });
    }

    // log parsed querystring
    LoggingAgent.info({ params: params });

    // write the parsed data into session storage
    await SessionStorageAgent.putJson("params", params);
}

/**
 * @param {import('@fstnetwork/loc-logic-sdk').GenericContext} ctx
 * @param {import('@fstnetwork/loc-logic-sdk').RailwayError} error
 */
export async function handleError(ctx, error) {
    // error logging
    LoggingAgent.error({
        error: true,
        errorMessage: error.message,
        stack: error.stack,
        taskKey: ctx.task.taskKey,
    });
}

TypeScript

querystring-parser.ts

import {
    GenericContext,
    RailwayError,
    LoggingAgent,
    SessionStorageAgent
} from "@fstnetwork/loc-logic-sdk";

export async function run(ctx: GenericContext) {
    // read payload
    const payload = await ctx.payload();

    if (!("http" in payload)) throw new Error("this logic only accepts http request");

    // get querystring (skip if empty)
    const query = payload.http.request.query;
    if (!query) return;

    let params = null;
    try {
        // parse querystring to object
        params = Object.fromEntries(new URLSearchParams(query));
    } catch (e) {
        LoggingAgent.warn({
            error: true,
            errorMessage: `unable to parse QueryString parameters: ${e.message}`
            stack: e.stack,
            taskKey: ctx.task.taskKey,
        });
    }

    // log parsed querystring
    LoggingAgent.info({ params: params });

    // write the parsed data into session storage
    await SessionStorageAgent.putJson("params", params);
}

export async function handleError(ctx: GenericContext, error: RailwayError) {
    // error logging
    LoggingAgent.error({
        error: true,
        errorMessage: error.message,
        stack: error.stack,
        taskKey: ctx.task.taskKey,
    });
}

tip

If the QueryString is ?name=Arthur-Dent&age=42, the params object will be parsed into

{
    name: "Arthur-Dent",
    age: 42
}