Class: Rhales::LinkBasedInjectionDetector

Inherits:
Object
  • Object
show all
Defined in:
lib/rhales/hydration/link_based_injection_detector.rb

Overview

Generates link-based hydration strategies that use browser resource hints and API endpoints instead of inline scripts

Supported Strategies

  • :link - Basic link reference: <link href="/api/hydration/template">
  • :prefetch - Background prefetch: <link rel="prefetch" href="..." as="fetch">
  • :preload - High priority preload: <link rel="preload" href="..." as="fetch">
  • :modulepreload - ES module preload: <link rel="modulepreload" href="..."
  • :lazy - Lazy loading with intersection observer

All strategies generate both link tags and accompanying JavaScript for data fetching and assignment to window objects.

Instance Method Summary collapse

Constructor Details

#initialize(hydration_config) ⇒ LinkBasedInjectionDetector

Returns a new instance of LinkBasedInjectionDetector.



23
24
25
26
27
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 23

def initialize(hydration_config)
  @hydration_config = hydration_config
  @api_endpoint_path = hydration_config.api_endpoint_path || '/api/hydration'
  @crossorigin_enabled = hydration_config.link_crossorigin.nil? ? true : hydration_config.link_crossorigin
end

Instance Method Details



48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 48

def generate_basic_link(template_name, window_attr, nonce)
  endpoint_url = "#{@api_endpoint_path}/#{template_name}"

  link_tag = %(<link href="#{endpoint_url}" type="application/json">)

  script_tag = <<~HTML.strip
    <script#{nonce_attribute(nonce)} data-hydration-target="#{window_attr}">
    // Load hydration data for #{window_attr}
    window.__rhales__ = window.__rhales__ || {};
    if (!window.__rhales__.loadData) {
      window.__rhales__.loadData = function(target, url) {
        fetch(url)
          .then(r => r.json())
          .then(data => window[target] = data);
      };
    }
    window.__rhales__.loadData('#{window_attr}', '#{endpoint_url}');
    </script>
  HTML

  "#{link_tag}\n#{script_tag}"
end

#generate_for_strategy(strategy, template_name, window_attr, nonce = nil) ⇒ Object 



29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 29

def generate_for_strategy(strategy, template_name, window_attr, nonce = nil)
  case strategy
  when :link
    generate_basic_link(template_name, window_attr, nonce)
  when :prefetch
    generate_prefetch_link(template_name, window_attr, nonce)
  when :preload
    generate_preload_link(template_name, window_attr, nonce)
  when :modulepreload
    generate_modulepreload_link(template_name, window_attr, nonce)
  when :lazy
    generate_lazy_loading(template_name, window_attr, nonce)
  else
    raise ArgumentError, "Unsupported link strategy: #{strategy}"
  end
end

#generate_lazy_loading(template_name, window_attr, nonce) ⇒ Object (private) 



141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 141

def generate_lazy_loading(template_name, window_attr, nonce)
  endpoint_url = "#{@api_endpoint_path}/#{template_name}"
  mount_selector = @hydration_config.lazy_mount_selector || '#app'

  # No link tag for lazy loading - purely script-driven
  script_tag = <<~HTML.strip
    <script#{nonce_attribute(nonce)} data-hydration-target="#{window_attr}" data-lazy-src="#{endpoint_url}">
    // Lazy loading strategy with intersection observer
    window.__rhales__ = window.__rhales__ || {};
    window.__rhales__.initLazyLoading = function() {
      const mountElement = document.querySelector('#{mount_selector}');
      if (!mountElement) {
        console.warn('Rhales: Mount element "#{mount_selector}" not found for lazy loading');
        return;
      }

      const observer = new IntersectionObserver((entries) => {
        entries.forEach(entry => {
          if (entry.isIntersecting) {
            fetch('#{endpoint_url}')
              .then(r => r.json())
              .then(data => {
                window['#{window_attr}'] = data;
                window.dispatchEvent(new CustomEvent('rhales:hydrated', {
                  detail: { target: '#{window_attr}', data: data }
                }));
              })
              .catch(err => console.error('Rhales lazy hydration error:', err));

            observer.unobserve(entry.target);
          }
        });
      });

      observer.observe(mountElement);
    };

    // Initialize when DOM is ready
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', window.__rhales__.initLazyLoading);
    } else {
      window.__rhales__.initLazyLoading();
    }
    </script>
  HTML

  script_tag
end

#generate_modulepreload_link(template_name, window_attr, nonce) ⇒ Object (private) 



120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 120

def generate_modulepreload_link(template_name, window_attr, nonce)
  endpoint_url = "#{@api_endpoint_path}/#{template_name}.js"

  link_tag = %(<link rel="modulepreload" href="#{endpoint_url}">)

  script_tag = <<~HTML.strip
    <script type="module"#{nonce_attribute(nonce)} data-hydration-target="#{window_attr}">
    // Module preload strategy
    import data from '#{endpoint_url}';
    window['#{window_attr}'] = data;

    // Dispatch ready event
    window.dispatchEvent(new CustomEvent('rhales:hydrated', {
      detail: { target: '#{window_attr}', data: data }
    }));
    </script>
  HTML

  "#{link_tag}\n#{script_tag}"
end

#generate_prefetch_link(template_name, window_attr, nonce) ⇒ Object (private) 



71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 71

def generate_prefetch_link(template_name, window_attr, nonce)
  endpoint_url = "#{@api_endpoint_path}/#{template_name}"
  crossorigin_attr = @crossorigin_enabled ? ' crossorigin' : ''

  link_tag = %(<link rel="prefetch" href="#{endpoint_url}" as="fetch"#{crossorigin_attr}>)

  script_tag = <<~HTML.strip
    <script#{nonce_attribute(nonce)} data-hydration-target="#{window_attr}">
    // Prefetch hydration data for #{window_attr}
    window.__rhales__ = window.__rhales__ || {};
    if (!window.__rhales__.loadPrefetched) {
      window.__rhales__.loadPrefetched = function(target, url) {
        fetch(url)
          .then(r => r.json())
          .then(data => window[target] = data);
      };
    }
    window.__rhales__.loadPrefetched('#{window_attr}', '#{endpoint_url}');
    </script>
  HTML

  "#{link_tag}\n#{script_tag}"
end

#generate_preload_link(template_name, window_attr, nonce) ⇒ Object (private) 



95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 95

def generate_preload_link(template_name, window_attr, nonce)
  endpoint_url = "#{@api_endpoint_path}/#{template_name}"
  crossorigin_attr = @crossorigin_enabled ? ' crossorigin' : ''

  link_tag = %(<link rel="preload" href="#{endpoint_url}" as="fetch"#{crossorigin_attr}>)

  script_tag = <<~HTML.strip
    <script#{nonce_attribute(nonce)} data-hydration-target="#{window_attr}">
    // Preload strategy - high priority fetch
    fetch('#{endpoint_url}')
      .then(r => r.json())
      .then(data => {
        window['#{window_attr}'] = data;
        // Dispatch ready event
        window.dispatchEvent(new CustomEvent('rhales:hydrated', {
          detail: { target: '#{window_attr}', data: data }
        }));
      })
      .catch(err => console.error('Rhales hydration error:', err));
    </script>
  HTML

  "#{link_tag}\n#{script_tag}"
end

#nonce_attribute(nonce) ⇒ Object (private) 



190
191
192
193
 
# File 'lib/rhales/hydration/link_based_injection_detector.rb', line 190

def nonce_attribute(nonce)
  require 'erb'
  nonce ? " nonce=\"#{ERB::Util.html_escape(nonce)}\"" : ''
end