Functions to manage url parameters from JavaScript context

manage_url_parameters.js

function parseUrlParameters(search) {
    var queryParts = {};

    var searchParts = search.split("&");
    for (var i = 0; i < searchParts.length; i++) {
        var searchPart = searchParts[i];

        var whitespaceIndex = searchPart.indexOf("=");

        if (whitespaceIndex !== -1) {
            var key = searchPart.substring(0, whitespaceIndex);
            var value = searchPart.substring(whitespaceIndex + 1);

            queryParts[key] = value;
        } else {
            queryParts[searchPart] = false;
        }
    }

    return queryParts;
}

function replaceUrlParameters(parameters) {
    history.replaceState(null, window.title, setUrlParameter(location.href, parameters));
}

function setUrlParameter(url, parameters) {
    if (!parameters) {
        return url;
    }

    var parser = document.createElement("a");
    parser.href = url;

    url = "";

    if (parser.protocol) {
        url += parser.protocol + "//";
    }

    if (parser.host) {
        url += parser.host;
    }

    if (parser.pathname) {
        url += parser.pathname;
    }

    var queryParts = {};

    if (parser.search) {
        queryParts = parseUrlParameters(parser.search.substring(1));
    }

    var parameterKeys = Object.keys(parameters);

    for (var i = 0; i < parameterKeys.length; i++) {
        var parameterKey = parameterKeys[i];

        let newValue = parameters[parameterKey];

        if (newValue === null) {
            delete queryParts[parameterKey];
        } else {
            queryParts[parameterKey] = newValue;
        }
    }


    var queryPartKeys = Object.keys(queryParts);

    var query = "";

    for (var i = 0; i < queryPartKeys.length; i++) {
        if (query.length === 0) {
            query += "?";
        }
        if (query.length > 1) {
            query += "&";
        }

        var queryPartKey = queryPartKeys[i];

        query += queryPartKey;

        if (queryParts[queryPartKey]) {
            query += "=";

            query += queryParts[queryPartKey];
        }
    }

    url += query;

    if (parser.hash) {
        url += parser.hash;
    }

    return url;
}


function getUrlParameters() {
    return parseUrlParameters(window.location.search.substring(1));
}

function getUrlParameter(key) {
    return getUrlParameters()[key];
}