Merge pull request #160 from phillc/page_size

Implements PageSize to requests

Author: phillc

README.md

@@ -94,7 +94,7 @@ kernels, err := linodego.ListKernels(context.Background(), opts)
 
 ```go
 opts := linodego.NewListOptions(2,"")
-// or opts := linodego.ListOptions{PageOptions: &PageOptions: {Page: 2 }}
+// or opts := linodego.ListOptions{PageOptions: &linodego.PageOptions{Page: 2}, PageSize: 500}
 kernels, err := linodego.ListKernels(context.Background(), opts)
 // len(kernels) == 100
 ```

pagination.go

@@ -23,7 +23,8 @@ type PageOptions struct {
 // ListOptions are the pagination and filtering (TODO) parameters for endpoints
 type ListOptions struct {
 	*PageOptions
-	Filter string
+	PageSize int
+	Filter   string
 }
 
 // NewListOptions simplified construction of ListOptions using only
@@ -32,28 +33,38 @@ func NewListOptions(page int, filter string) *ListOptions {
 	return &ListOptions{PageOptions: &PageOptions{Page: page}, Filter: filter}
 }
 
+func applyListOptionsToRequest(opts *ListOptions, req *resty.Request) {
+	if opts != nil {
+		if opts.PageOptions != nil && opts.Page > 0 {
+			req.SetQueryParam("page", strconv.Itoa(opts.Page))
+		}
+
+		if opts.PageSize > 0 {
+			req.SetQueryParam("page_size", strconv.Itoa(opts.PageSize))
+		}
+
+		if len(opts.Filter) > 0 {
+			req.SetHeader("X-Filter", opts.Filter)
+		}
+	}
+}
+
 // listHelper abstracts fetching and pagination for GET endpoints that
 // do not require any Ids (top level endpoints).
 // When opts (or opts.Page) is nil, all pages will be fetched and
 // returned in a single (endpoint-specific)PagedResponse
 // opts.results and opts.pages will be updated from the API response
 // nolint
 func (c *Client) listHelper(ctx context.Context, i interface{}, opts *ListOptions) error {
-	req := c.R(ctx)
-	if opts != nil && opts.PageOptions != nil && opts.Page > 0 {
-		req.SetQueryParam("page", strconv.Itoa(opts.Page))
-	}
-
 	var (
 		err     error
 		pages   int
 		results int
 		r       *resty.Response
 	)
 
-	if opts != nil && len(opts.Filter) > 0 {
-		req.SetHeader("X-Filter", opts.Filter)
-	}
+	req := c.R(ctx)
+	applyListOptionsToRequest(opts, req)
 
 	switch v := i.(type) {
 	case *LinodeKernelsPagedResponse:
@@ -295,23 +306,17 @@ func (c *Client) listHelper(ctx context.Context, i interface{}, opts *ListOption
 // opts.results and opts.pages will be updated from the API response
 // nolint
 func (c *Client) listHelperWithID(ctx context.Context, i interface{}, idRaw interface{}, opts *ListOptions) error {
-	req := c.R(ctx)
-	if opts != nil && opts.Page > 0 {
-		req.SetQueryParam("page", strconv.Itoa(opts.Page))
-	}
-
 	var (
 		err     error
 		pages   int
 		results int
 		r       *resty.Response
 	)
 
-	id, _ := idRaw.(int)
+	req := c.R(ctx)
+	applyListOptionsToRequest(opts, req)
 
-	if opts != nil && len(opts.Filter) > 0 {
-		req.SetHeader("X-Filter", opts.Filter)
-	}
+	id, _ := idRaw.(int)
 
 	switch v := i.(type) {
 	case *DomainRecordsPagedResponse:
@@ -436,23 +441,17 @@ func (c *Client) listHelperWithID(ctx context.Context, i interface{}, idRaw inte
 // When opts (or opts.Page) is nil, all pages will be fetched and
 // returned in a single (endpoint-specific)PagedResponse
 // opts.results and opts.pages will be updated from the API response
+// nolint
 func (c *Client) listHelperWithTwoIDs(ctx context.Context, i interface{}, firstID, secondID int, opts *ListOptions) error {
-	req := c.R(ctx)
-
-	if opts != nil && opts.Page > 0 {
-		req.SetQueryParam("page", strconv.Itoa(opts.Page))
-	}
-
 	var (
 		err     error
 		pages   int
 		results int
 		r       *resty.Response
 	)
 
-	if opts != nil && len(opts.Filter) > 0 {
-		req.SetHeader("X-Filter", opts.Filter)
-	}
+	req := c.R(ctx)
+	applyListOptionsToRequest(opts, req)
 
 	switch v := i.(type) {
 	case *NodeBalancerNodesPagedResponse: