Analyze article text content (#22)

dist/manifest.json

@@ -1,7 +1,7 @@
 {
     "manifest_version": 3,
     "name": "Bias Monitor",
-    "version": "1.1.1", 
+    "version": "1.2.0", 
 
     "description": "Gain insight on the political bias of a news article.",
     "icons": {
@@ -10,7 +10,13 @@
         "128": "./imgs/128.png"
     },
 
+    "background": {
+        "service_worker": "background.js"
+    },
+
     "permissions": [
+        "activeTab",
+        "scripting",
         "tabs",
         "storage"
     ],
@@ -22,8 +28,5 @@
         },
         "default_title": "Check this site's bias",
         "default_popup": "index.html"
-    },
-    "host_permissions":[
-        "*://*/"
-    ] 
+    }
 }

src/background.js

@@ -0,0 +1,41 @@
+/**
+ * Kick off the scripts conditional to if the base url
+ * is a news site or not.
+ * 
+ * @param {*} tab_id 
+ * @param {*} tab 
+ */
+async function kick_off_script(tab_id, tab) {
+    try {
+        await chrome.scripting.executeScript({
+            target: { tabId: tab_id },
+            files: ["./content.js"],
+        });
+    } catch(error) {
+        console.debug(error)
+    }
+}
+
+
+/**
+ * Fires on selecting new tabs.
+ */
+chrome.tabs.onActivated.addListener(async (activeInfo) => {
+    chrome.tabs.query({
+    active: true,
+    lastFocusedWindow: true
+    }, async function(tabs) {
+        const tab_id = activeInfo.tabId;
+        const tab = tabs[0]
+        await kick_off_script(tab_id, tab);
+    });
+});
+
+
+/**
+ * Fires on tabs updating, such as reloads.
+ */
+chrome.tabs.onUpdated.addListener(async (tabID, changeInfo, tab) => {
+    if(changeInfo.status == "complete")
+        await kick_off_script(tabID, tab);
+});

src/bias_runner.js

@@ -10,9 +10,38 @@ export default class BiasRunner {
     static async run(active_tab) {
         BiasRunner.page_content = active_tab.title;
         BiasRunner.website_url = active_tab.url;
+        await this.set_page_content();
         await this.update_and_display();
     }
 
+    static async set_page_content() {
+        let page_content = false;
+
+        const max_retries = 11;
+        for(let i = 0; i < max_retries && !page_content; ++i) {
+            const exponential_backoff = Math.pow(2, i);
+            await this.sleep(exponential_backoff)
+            page_content = await this._get_content_from_local_storage();
+        }
+
+        BiasRunner.page_content += page_content;
+    }
+
+    static _get_content_from_local_storage() {
+        return new Promise(function(resolve, reject) {
+            try {
+                chrome.storage.local.get({page_content: {}}, function(result) {
+                    if(BiasRunner.website_url in result.page_content)
+                        resolve(result.page_content[BiasRunner.website_url]);
+                    else
+                        resolve(false);
+                });
+            } catch (error) {
+                resolve(false);
+            }
+        });
+    }
+
     static async update_and_display() {
         let current_bias_score;
         const has_cached_rating = await this._has_cached_rating();
@@ -74,4 +103,10 @@ export default class BiasRunner {
             });
         });
     }
+
+    static sleep(milliseconds) {
+        return new Promise(
+            resolve => setTimeout(resolve, milliseconds)
+        );
+    }
 }

src/content.js

@@ -0,0 +1,44 @@
+async function main() {
+    const page_content = get_page_content();
+    await set_local_storage(page_content);
+}
+
+
+function get_page_content() {
+    const considered_tags = ["h1"];
+    let content = "";
+
+    for (const tag of considered_tags) {
+        const element_arr = document.getElementsByTagName(tag);
+        for (const element of element_arr) {
+            content += element.textContent
+            content += " " 
+        }
+    }
+    const sample_size = 800;
+    const body_text = document.body.innerText;
+    const start_sample = parseInt(body_text.length/10);
+    let body_text_sample = body_text.slice(start_sample, start_sample+sample_size);
+    content += body_text_sample;
+
+    return content;
+}
+
+
+async function set_local_storage(page_content) {
+    return new Promise(function(resolve, reject) {
+        const website_url = window.location.toString();
+        let url_to_content_map = {}
+        url_to_content_map[website_url] = page_content;
+
+        chrome.storage.local.set(
+            {page_content: url_to_content_map},
+            function() {
+                resolve();
+            }
+        );
+    });
+}
+
+
+main();

src/services/post_service.js

@@ -68,10 +68,7 @@ export default class PostService {
 
 
   /**
-   * The responses we get back are mostly in the [-2, 2]
-   * range because we don't send over large requests
-   * with lots of text data. This applies a cusp
-   * transformation to amplify some of the small numbers.
+   * A cusp transformation amplifys some of the small numbers.
    * 
    * @param {*} result 
    * @returns a float after a cusp transformation
@@ -82,8 +79,7 @@ export default class PostService {
     const abs_result_float = Math.abs(result_float);
 
     const squash = 5.7;
-    const vertical_shift = 3;
-    const transformed_val = squash*Math.pow(abs_result_float, 1/2) + vertical_shift;
+    const transformed_val = squash*Math.pow(abs_result_float, 1/2);
 
     return is_negative ? -1*transformed_val : transformed_val; 
   }

webpack.config.js

@@ -11,9 +11,11 @@ if (process.env.TESTBUILD) {
 module.exports = {
   entry: {
     main: entry,
+    background: './src/background.js',
+    content: './src/content.js',
   },
   output: {
       path: output_path,
       filename: '[name].js'
   },
-};
+};