added views

templating/context.go

@@ -0,0 +1,141 @@
+package templating
+
+import (
+	"html/template"
+	"io/fs"
+	"path/filepath"
+	"slices"
+	"strings"
+)
+
+type TemplateContext struct {
+	//  WARNING: Path is a URL path, NOT a filesystem path
+	Path string
+	//  WARNING: The keys of these maps are template names, NOT filesystem paths
+	// The values are FS paths absolute from the root directory of the templates FS
+	locals  map[string]string
+	globals map[string]string
+}
+
+func NewTemplateContext(path string) TemplateContext {
+	return TemplateContext{
+		Path:    path,
+		locals:  make(map[string]string),
+		globals: make(map[string]string),
+	}
+}
+
+func (c *TemplateContext) Parse(fsys fs.FS) error {
+	fspath := PathToFSPath(c.Path)
+	entries, err := fs.ReadDir(fsys, fspath)
+
+	if err != nil {
+		return NewError(InvalidPathError, c.Path)
+	}
+
+	for _, e := range entries {
+		if e.IsDir() {
+			// INFO: components in the components directory can be overwritten
+			// by components in the base directory down below
+			// TODO: Maybe allow for subdirectories in the components directory?
+			if e.Name() == TEMPLATE_COMPONENT_DIRECTORY {
+				entries, err := fs.ReadDir(fsys, filepath.Join(fspath, e.Name()))
+				if err != nil {
+					return NewError(FileAccessError, filepath.Join(fspath, e.Name()))
+				}
+
+				for _, e := range entries {
+					ext := filepath.Ext(e.Name())
+
+					if !slices.Contains(TEMPLATE_FORMATS, ext) {
+						continue
+					}
+
+					name := strings.TrimSuffix(e.Name(), ext)
+					if strings.HasPrefix(e.Name(), TEMPLATE_GLOBAL_PREFIX) {
+						c.globals[name] = filepath.Join(fspath, TEMPLATE_COMPONENT_DIRECTORY, e.Name())
+					} else {
+						c.locals[name] = filepath.Join(fspath, TEMPLATE_COMPONENT_DIRECTORY, e.Name())
+					}
+				}
+				continue
+			}
+		}
+
+		ext := filepath.Ext(e.Name())
+
+		if !slices.Contains(TEMPLATE_FORMATS, ext) {
+			continue
+		}
+
+		name := strings.TrimSuffix(e.Name(), ext)
+		if strings.HasPrefix(e.Name(), TEMPLATE_GLOBAL_PREFIX) {
+			c.globals[name] = filepath.Join(fspath, e.Name())
+		} else {
+			c.locals[name] = filepath.Join(fspath, e.Name())
+		}
+	}
+
+	return nil
+}
+
+func (c *TemplateContext) SetGlobals(globals map[string]string) error {
+	// INFO: this allows for overwriting of existing global keys.
+	// Make sure to call this appopriately before or after Parse(), depending on your use case
+	for k, v := range globals {
+		c.globals[k] = v
+	}
+	return nil
+}
+
+func (c *TemplateContext) Globals() map[string]string {
+	return c.globals
+}
+
+func (c *TemplateContext) Template(fsys fs.FS) (*template.Template, error) {
+	t, err := readTemplates(fsys, nil, c.globals)
+	if err != nil {
+		return nil, err
+	}
+
+	t, err = readTemplates(fsys, t, c.locals)
+	if err != nil {
+		return nil, err
+	}
+
+	return t, nil
+}
+
+func readTemplates(fsys fs.FS, t *template.Template, paths map[string]string) (*template.Template, error) {
+	for k, v := range paths {
+		text, err := fs.ReadFile(fsys, v)
+		if err != nil {
+			return nil, NewError(FileAccessError, v)
+		}
+
+		temp, err := template.New(k).Parse(string(text))
+		if err != nil {
+			return nil, err
+		}
+
+		if t == nil {
+			t = temp
+			continue
+		}
+
+		for _, template := range temp.Templates() {
+			_, err = t.AddParseTree(template.Name(), template.Tree)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		_, err = t.AddParseTree(temp.Name(), temp.Tree)
+		if err != nil {
+			return nil, err
+		}
+
+	}
+
+	return t, nil
+}