adding csv format interface and handler impl

4 files changed, 188 insertions, 4 deletions

diff --git a/management/format/csv.go b/management/format/csv.go
new file mode 100644
index 0000000..fd8ad33
--- /dev/null
+++ b/management/format/csv.go
@@ -0,0 +1,9 @@
+// Package format provides interfaces to format content into various kinds of
+// data
+package format
+
+// CSVFormattable is implemented with the method FormatCSV, which must return the ordered
+// slice of JSON struct tag names for the type implmenting it
+type CSVFormattable interface {
+	FormatCSV() []string
+}
diff --git a/system/admin/export.go b/system/admin/export.go
new file mode 100644
index 0000000..82b5279
--- /dev/null
+++ b/system/admin/export.go
@@ -0,0 +1,133 @@
+package admin
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"encoding/csv"
+
+	"io/ioutil"
+	"os"
+
+	"github.com/ponzu-cms/ponzu/management/format"
+	"github.com/ponzu-cms/ponzu/system/db"
+	"github.com/ponzu-cms/ponzu/system/item"
+	"github.com/tidwall/gjson"
+)
+
+func exportHandler(res http.ResponseWriter, req *http.Request) {
+	// /admin/contents/export?type=Blogpost&format=csv
+	q := req.URL.Query()
+	t := q.Get("type")
+	f := strings.ToLower(q.Get("format"))
+
+	if t == "" || f == "" {
+		v, err := Error400()
+		if err != nil {
+			res.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		res.WriteHeader(http.StatusBadRequest)
+		_, err = res.Write(v)
+		if err != nil {
+			res.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+	}
+
+	pt, ok := item.Types[t]
+	if !ok {
+		res.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	switch f {
+	case "csv":
+		csv, ok := pt().(format.CSVFormattable)
+		if !ok {
+			res.WriteHeader(http.StatusBadRequest)
+			return
+		}
+
+		fields := csv.FormatCSV()
+		exportCSV(res, req, pt, fields)
+
+	default:
+		res.WriteHeader(http.StatusBadRequest)
+		return
+	}
+}
+
+func exportCSV(res http.ResponseWriter, req *http.Request, pt func() interface{}, fields []string) {
+	tmpFile, err := ioutil.TempFile(os.TempDir(), "exportcsv-")
+	if err != nil {
+		log.Println("Failed to create tmp file for CSV export:", err)
+		res.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	defer os.Remove(filepath.Join(os.TempDir(), tmpFile.Name()))
+	defer tmpFile.Close()
+
+	csvBuf := csv.NewWriter(tmpFile)
+
+	t := req.URL.Query().Get("type")
+
+	// get content data and loop through creating a csv row per result
+	bb := db.ContentAll(t)
+
+	err = csvBuf.Write(fields)
+	if err != nil {
+		res.WriteHeader(http.StatusInternalServerError)
+		log.Println("Failed to write column headers:", fields)
+		return
+	}
+
+	for row := range bb {
+		// unmarshal data and loop over fields
+		rowBuf := []string{}
+
+		for _, col := range fields {
+			// pull out each field as the column value
+			result := gjson.GetBytes(bb[row], col)
+
+			// append it to the buffer
+			rowBuf = append(rowBuf, result.String())
+		}
+
+		// write row to csv
+		err := csvBuf.Write(rowBuf)
+		if err != nil {
+			res.WriteHeader(http.StatusInternalServerError)
+			log.Println("Failed to write column headers:", fields)
+			return
+		}
+	}
+
+	// write the buffer to a content-disposition response
+	csvB, err := ioutil.ReadAll(tmpFile)
+	if err != nil {
+		log.Println("Failed to read tmp file for CSV export:", err)
+		res.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	ts := time.Now().Unix()
+	disposition := `attachment; filename="export-%s-%d.csv"`
+
+	res.Header().Set("Content-Type", "text/csv")
+	res.Header().Set("Content-Disposition", fmt.Sprintf(disposition, t, ts))
+	res.Header().Set("Content-Length", fmt.Sprintf("%d", len(csvB)))
+
+	_, err = res.Write(csvB)
+	if err != nil {
+		log.Println("Failed to write tmp file to response for CSV export:", err)
+		res.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}
diff --git a/system/admin/handlers.go b/system/admin/handlers.go
index 23c7e50..2a76e58 100644
--- a/system/admin/handlers.go
+++ b/system/admin/handlers.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/ponzu-cms/ponzu/management/editor"
+	"github.com/ponzu-cms/ponzu/management/format"
 	"github.com/ponzu-cms/ponzu/management/manager"
 	"github.com/ponzu-cms/ponzu/system/addon"
 	"github.com/ponzu-cms/ponzu/system/admin/config"
@@ -1492,8 +1493,24 @@ func contentsHandler(res http.ResponseWriter, req *http.Request) {
 	</script>
 	`
 
-	btn := `<div class="col s3"><a href="/admin/edit?type=` + t + `" class="btn new-post waves-effect waves-light">New ` + t + `</a></div></div>`
-	html = html + b.String() + script + btn
+	btn := `<div class="col s3">
+		<a href="/admin/edit?type=` + t + `" class="btn new-post waves-effect waves-light">
+			New ` + t + `
+		</a>
+		</div>`
+	html = html + b.String() + btn
+
+	if _, ok := pt.(format.CSVFormattable); ok {
+		btn = `<div class="col s3">
+				<a href="/admin/edit/export?type=` + t + `&format=csv" class="green darken-4 btn export-post waves-effect waves-light">
+					<i class="material-icons left">system_update_alt</i>
+					.CSV
+				</a>
+				</div>`
+		html = html + b.String() + btn
+	}
+
+	html += `</div>` + script
 
 	adminView, err := Admin([]byte(html))
 	if err != nil {
@@ -2422,7 +2439,15 @@ func searchHandler(res http.ResponseWriter, req *http.Request) {
 
 	posts := db.ContentAll(t + specifier)
 	b := &bytes.Buffer{}
-	p := item.Types[t]().(editor.Editable)
+	pt, ok := item.Types[t]
+	if !ok {
+		res.WriteHeader(http.StatusBadRequest)
+		return
+	}
+
+	post := pt()
+
+	p := post.(editor.Editable)
 
 	html := `<div class="col s9 card">		
 					<div class="card-content">
@@ -2499,9 +2524,25 @@ func searchHandler(res http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	btn := `<div class="col s3"><a href="/admin/edit?type=` + t + `" class="btn new-post waves-effect waves-light">New ` + t + `</a></div></div>`
+	btn := `<div class="col s3">
+			<a href="/admin/edit?type=` + t + `" class="btn new-post waves-effect waves-light">
+				New ` + t + `
+			</a>
+			</div>`
 	html = html + b.String() + btn
 
+	if _, ok := post.(format.CSVFormattable); ok {
+		btn = `<div class="col s3">
+				<a href="/admin/edit/export?type=` + t + `&format=csv" class="green darken-4 btn export-post waves-effect waves-light">
+					<i class="material-icons left">system_update_alt</i>
+					.CSV
+				</a>
+				</div>`
+		html = html + b.String() + btn
+	}
+
+	html += `</div>`
+
 	adminView, err := Admin([]byte(html))
 	if err != nil {
 		log.Println(err)
diff --git a/system/admin/server.go b/system/admin/server.go
index 2180441..426dabd 100644
--- a/system/admin/server.go
+++ b/system/admin/server.go
@@ -37,6 +37,7 @@ func Run() {
 
 	http.HandleFunc("/admin/contents", user.Auth(contentsHandler))
 	http.HandleFunc("/admin/contents/search", user.Auth(searchHandler))
+	http.HandleFunc("/admin/contents/export", user.Auth(exportHandler))
 
 	http.HandleFunc("/admin/edit", user.Auth(editHandler))
 	http.HandleFunc("/admin/edit/delete", user.Auth(deleteHandler))