Graphql Builder for Salesforce Apex

graphBuilder.apex

public class GraphBuilder {
    
    /*

    EXAMPLE
    -------

    String q = new GraphBuilder.QueryOperation(
        new GraphBuilder.QueryResolver(
            'notification',
            new List<GraphBuilder.QueryResolverParameter> {
                new GraphBuilder.QueryResolverParameter('limit', 5),
                new GraphBuilder.QueryResolverParameter('offset', '25'),
                new GraphBuilder.QueryResolverParameter('filterValue', 'SUCCESS', true)
            },
            new List<GraphBuilder.QueryResolverAttribute> {
                new GraphBuilder.QueryResolverAttribute('key'),
                new GraphBuilder.QueryResolverAttribute('message'),
                new GraphBuilder.QueryResolverAttribute(
                    'executions',
                    new List<GraphBuilder.QueryResolverAttribute> {
                        new GraphBuilder.QueryResolverAttribute('executionKey'),
                        new GraphBuilder.QueryResolverAttribute('description'),
                        new GraphBuilder.QueryResolverAttribute(
                            'owner',
                            new List<GraphBuilder.QueryResolverAttribute> {
                                new GraphBuilder.QueryResolverAttribute('ownerName'),
                                new GraphBuilder.QueryResolverAttribute('email')
                            }
                        )
                    }
                ),
                new GraphBuilder.QueryResolverAttribute('createdAt')
            }
        )
    ).toString();

    ----

    query {
        notification(
            limit: 5,
            offset: 25,
            filterValue: \"SUCCESS\"
        ){
            key
            message
            executions {
                executionKey
                description
                owner {
                    ownerName
                    email
                }
            }
            createdAt
        }
    }

    */

    public class QueryOperation {

        private List<QueryResolver> resolvers { get; set; }

        public QueryOperation(QueryResolver resolver) {
            this(new List<QueryResolver> { resolver });
        }

        public QueryOperation(List<QueryResolver> resolverList) {
            this.resolvers = resolverList;
        }

        public override String toString() {
            String response = 'query {\n';

            if (this.resolvers != null) {
                for (QueryResolver resolver : this.resolvers) {
                    response += resolver.toString();
                }
            }

            response += '}\n';
            return response;
        }
    }

    public class QueryResolver {

        private String name { get; set; }
        private List<QueryResolverParameter> parameters { get; set; }
        private List<QueryResolverAttribute> attributes { get; set; }

        public QueryResolver(String resolverName, List<QueryResolverAttribute> attributeList) {
            this(resolverName, null, attributeList);
        }

        public QueryResolver(String resolverName, List<QueryResolverParameter> parameterList, List<QueryResolverAttribute> attributeList) {
            this.name = resolverName;
            this.parameters = parameterList;
            this.attributes = attributeList;
        }

        public override String toString() {
            String response = '    ' + this.name;
            
            if (this.parameters != null) {
                response += '(\n';
                for (Integer i = 0; i < this.parameters.size(); i++) {
                    response += '        ' + this.parameters[i].toString();
                    if (i != this.parameters.size()-1) response += ',';
                    response += '\n';
                }
                response += '    ){\n';
            }
            else
                response +=  ' {\n';

            if (this.attributes != null && this.attributes.size() > 0) {
                for (QueryResolverAttribute attribute : this.attributes) {
                    response += attribute.toString();
                }
            }
            
            response += '    }\n';

            return response;
        }

    }

    public class QueryResolverParameter {

        private String name { get; set; }
        private Object value { get; set; }
        private Boolean escapeValue { get; set; }

        public QueryResolverParameter(String parameterName, Object parameterValue) {
            this(parameterName, parameterValue, false);
        }

        public QueryResolverParameter(String parameterName, Object parameterValue, Boolean escapeParameterValue) {
            this.name = parameterName;
            this.value = parameterValue;
            this.escapeValue = escapeParameterValue;            
        }

        public override String toString() {
            String responseValue = (this.escapeValue == true) ? '"' + String.valueOf(this.value) + '"' : String.valueOf(this.value);
            return this.name + ': ' + ((this.escapeValue == true) ? responseValue.escapeEcmaScript() : responseValue);
        }
    }

    public class QueryResolverAttribute {

        private String name { get; set; }
        private List<QueryResolverAttribute> children { get; set; }

        public QueryResolverAttribute(String attributeName) {
            this(attributeName, null);
        }

        public QueryResolverAttribute(String attributeName, List<QueryResolverAttribute> childrenList) {
            this.name = attributeName;
            this.children = childrenList;
        }

        public override String toString() {
            return this.toString(1); 
        }

        public String toString(Integer indent) {
            String indentation = '';
            for (Integer i = 0; i <= indent; i++) {
                indentation += '    ';
            }

            String response = indentation + this.name;

            if (this.children != null && this.children.size() > 0) {
                response += ' {\n';
                for (QueryResolverAttribute attribute : this.children) {
                    response += attribute.toString(indent + 1);
                }
                response += indentation + '}';
            }

            response += '\n';
            return response;
        }
    }

}